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Clayborn Hall Lessons
 

GRADE TEN --LESSON TWELVE

The material in this lesson represents approximately five days of work for most students assisted daily by an at-home teacher. Students do best when the at-home teacher and student together cover every subject, every day. Feel free to progress through this material at the pace that best suits you both.

Please use the Internet, books, magazines, articles and other research materials to find additional information on a subject. It is always a good idea to research topics through a variety of sources

 

 

Literature 
Know the authors and know their works

Julius Caesar by William Shakespeare
           
(Short lines are original prose format)

                 

ACT V

        

SCENE I. The plains of Philippi.

Enter OCTAVIUS, ANTONY, and their army

OCTAVIUS

Now, Antony, our hopes are answered:
You said the enemy would not come down,
But keep the hills and upper regions;
It proves not so: their battles are at hand;
They mean to warn us at Philippi here,
Answering before we do demand of them.

ANTONY

Tut, I am in their bosoms, and I know
Wherefore they do it: they could be content
To visit other places; and come down
With fearful bravery, thinking by this face
To fasten in our thoughts that they have courage;
But 'tis not so.Enter a Messenger

Messenger

Prepare you, generals:
The enemy comes on in gallant show;
Their bloody sign of battle is hung out,
And something to be done immediately.

ANTONY

Octavius, lead your battle softly on,
Upon the left hand of the even field.

OCTAVIUS

Upon the right hand I; keep thou the left.

ANTONY

Why do you cross me in this exigent?

OCTAVIUS

I do not cross you; but I will do so. March   Drum. Enter BRUTUS, CASSIUS, and their Army; LUCILIUS, TITINIUS, MESSALA, and others

BRUTUS

They stand, and would have parley.

CASSIUS

Stand fast, Titinius: we must out and talk.

OCTAVIUS

Mark Antony, shall we give sign of battle?

ANTONY

No, Caesar, we will answer on their charge.
Make forth; the generals would have some words.

OCTAVIUS

Stir not until the signal.

BRUTUS

Words before blows: is it so, countrymen?

OCTAVIUS

Not that we love words better, as you do.

BRUTUS

Good words are better than bad strokes, Octavius.

ANTONY

In your bad strokes, Brutus, you give good words:
Witness the hole you made in Caesar's heart,
Crying 'Long live! hail, Caesar!'

CASSIUS

Antony,
The posture of your blows are yet unknown;
But for your words, they rob the Hybla bees,
And leave them honeyless.

ANTONY

Not stingless too.

BRUTUS

O, yes, and soundless too;
For you have stol'n their buzzing, Antony,
And very wisely threat before you sting.

ANTONY

Villains, you did not so, when your vile daggers
Hack'd one another in the sides of Caesar:
You show'd your teeth like apes, and fawn'd like hounds,
And bow'd like bondmen, kissing Caesar's feet;
Whilst damned Casca, like a cur, behind
Struck Caesar on the neck. O you flatterers!

CASSIUS

Flatterers! Now, Brutus, thank yourself:
This tongue had not offended so to-day,
If Cassius might have ruled.

OCTAVIUS

Come, come, the cause: if arguing make us sweat,
The proof of it will turn to redder drops. Look;
I draw a sword against conspirators;
When think you that the sword goes up again?
Never, till Caesar's three and thirty wounds
Be well avenged; or till another Caesar
Have added slaughter to the sword of traitors.

BRUTUS

Caesar, thou canst not die by traitors' hands,
Unless thou bring'st them with thee.

OCTAVIUS

So I hope;
I was not born to die on Brutus' sword.

BRUTUS

O, if thou wert the noblest of thy strain,
Young man, thou couldst not die more honourable.

CASSIUS

A peevish schoolboy, worthless of such honour,
Join'd with a masker and a reveller!

ANTONY

Old Cassius still!

OCTAVIUS

Come, Antony, away!
Defiance, traitors, hurl we in your teeth:
If you dare fight to-day, come to the field;
If not, when you have stomachs.     Exeunt OCTAVIUS, ANTONY, and their army

CASSIUS

Why, now, blow wind, swell billow and swim bark!
The storm is up, and all is on the hazard.

BRUTUS

Ho, Lucilius! hark, a word with you.

LUCILIUS

[Standing forth] My lord?     BRUTUS and LUCILIUS converse apart

CASSIUS

Messala!

MESSALA

[Standing forth] What says my general?

CASSIUS

Messala,
This is my birth-day; as this very day
Was Cassius born. Give me thy hand, Messala:
Be thou my witness that against my will,
As Pompey was, am I compell'd to set
Upon one battle all our liberties.
You know that I held Epicurus strong
And his opinion: now I change my mind,
And partly credit things that do presage.
Coming from Sardis, on our former ensign
Two mighty eagles fell, and there they perch'd,
Gorging and feeding from our soldiers' hands;
Who to Philippi here consorted us:
This morning are they fled away and gone;
And in their steads do ravens, crows and kites,
Fly o'er our heads and downward look on us,
As we were sickly prey: their shadows seem
A canopy most fatal, under which
Our army lies, ready to give up the ghost.

MESSALA

Believe not so.

CASSIUS

I but believe it partly;
For I am fresh of spirit and resolved
To meet all perils very constantly.

BRUTUS

Even so, Lucilius.

CASSIUS

Now, most noble Brutus,
The gods to-day stand friendly, that we may,
Lovers in peace, lead on our days to age!
But since the affairs of men rest still incertain,
Let's reason with the worst that may befall.
If we do lose this battle, then is this
The very last time we shall speak together:
What are you then determined to do?

BRUTUS

Even by the rule of that philosophy
By which I did blame Cato for the death
Which he did give himself, I know not how,
But I do find it cowardly and vile,
For fear of what might fall, so to prevent
The time of life: arming myself with patience
To stay the providence of some high powers
That govern us below.

CASSIUS

Then, if we lose this battle,
You are contented to be led in triumph
Thorough the streets of Rome?

BRUTUS

No, Cassius, no: think not, thou noble Roman,
That ever Brutus will go bound to Rome;
He bears too great a mind. But this same day
Must end that work the ides of March begun;
And whether we shall meet again I know not.
Therefore our everlasting farewell take:
For ever, and for ever, farewell, Cassius!
If we do meet again, why, we shall smile;
If not, why then, this parting was well made.

CASSIUS

For ever, and for ever, farewell, Brutus!
If we do meet again, we'll smile indeed;
If not, 'tis true this parting was well made.

BRUTUS

Why, then, lead on. O, that a man might know
The end of this day's business ere it come!
But it sufficeth that the day will end,
And then the end is known. Come, ho! away!    Exeunt

SCENE II. The same. The field of battle.     Alarum. Enter BRUTUS and MESSALA

BRUTUS    Ride, ride, Messala, ride, and give these bills
Unto the legions on the other side.
    Loud alarum

Let them set on at once; for I perceive
But cold demeanor in Octavius' wing,
And sudden push gives them the overthrow.
Ride, ride, Messala: let them all come down.    Exeunt

SCENE III. Another part of the field.   Alarums. Enter CASSIUS and TITINIUS

CASSIUS

O, look, Titinius, look, the villains fly!
Myself have to mine own turn'd enemy:
This ensign here of mine was turning back;
I slew the coward, and did take it from him.

TITINIUS

O Cassius, Brutus gave the word too early;
Who, having some advantage on Octavius,
Took it too eagerly: his soldiers fell to spoil,
Whilst we by Antony are all enclosed.     Enter PINDARUS

PINDARUS

Fly further off, my lord, fly further off;
Mark Antony is in your tents, my lord
Fly, therefore, noble Cassius, fly far off.

CASSIUS

This hill is far enough. Look, look, Titinius;
Are those my tents where I perceive the fire?

TITINIUS

They are, my lord.

CASSIUS

Titinius, if thou lovest me,
Mount thou my horse, and hide thy spurs in him,
Till he have brought thee up to yonder troops,
And here again; that I may rest assured
Whether yond troops are friend or enemy.

TITINIUS

I will be here again, even with a thought.      Exit

CASSIUS

Go, Pindarus, get higher on that hill;
My sight was ever thick; regard Titinius,
And tell me what thou notest about the field.    PINDARUS ascends the hill

This day I breathed first: time is come round,
And where I did begin, there shall I end;
My life is run his compass. Sirrah, what news?

PINDARUS

[Above] O my lord!

CASSIUS

What news?

PINDARUS

[Above] Titinius is enclosed round about
With horsemen, that make to him on the spur;
Yet he spurs on. Now they are almost on him.
Now, Titinius! Now some light. O, he lights too.
He's ta'en.        Shout

And, hark! they shout for joy.

CASSIUS

Come down, behold no more.
O, coward that I am, to live so long,
To see my best friend ta'en before my face!     PINDARUS descends

Come hither, sirrah:
In Parthia did I take thee prisoner;
And then I swore thee, saving of thy life,
That whatsoever I did bid thee do,
Thou shouldst attempt it. Come now, keep thine oath;
Now be a freeman: and with this good sword,
That ran through Caesar's bowels, search this bosom.
Stand not to answer: here, take thou the hilts;
And, when my face is cover'd, as 'tis now,
Guide thou the sword.     PINDARUS stabs him

Caesar, thou art revenged,
Even with the sword that kill'd thee.    Dies

PINDARUS

So, I am free; yet would not so have been,
Durst I have done my will. O Cassius,
Far from this country Pindarus shall run,
Where never Roman shall take note of him.       Exit      Re-enter TITINIUS with MESSALA

MESSALA

It is but change, Titinius; for Octavius
Is overthrown by noble Brutus' power,
As Cassius' legions are by Antony.

TITINIUS

These tidings will well comfort Cassius.

MESSALA

Where did you leave him?

TITINIUS

All disconsolate,
With Pindarus his bondman, on this hill.

MESSALA

Is not that he t hat lies upon the ground?

TITINIUS

He lies not like the living. O my heart!

MESSALA

Is not that he?

TITINIUS

No, this was he, Messala,
But Cassius is no more. O setting sun,
As in thy red rays thou dost sink to-night,
So in his red blood Cassius' day is set;
The sun of Rome is set! Our day is gone;
Clouds, dews, and dangers come; our deeds are done!
Mistrust of my success hath done this deed.

MESSALA

Mistrust of good success hath done this deed.
O hateful error, melancholy's child,
Why dost thou show to the apt thoughts of men
The things that are not? O error, soon conceived,
Thou never comest unto a happy birth,
But kill'st the mother that engender'd thee!

TITINIUS

What, Pindarus! where art thou, Pindarus?

MESSALA

Seek him, Titinius, whilst I go to meet
The noble Brutus, thrusting this report
Into his ears; I may say, thrusting it;
For piercing steel and darts envenomed
Shall be as welcome to the ears of Brutus
As tidings of this sight.

TITINIUS

Hie you, Messala,
And I will seek for Pindarus the while.     Exit MESSALA

Why didst thou send me forth, brave Cassius?
Did I not meet thy friends? and did not they
Put on my brows this wreath of victory,
And bid me give it thee? Didst thou not hear their shouts?
Alas, thou hast misconstrued every thing!
But, hold thee, take this garland on thy brow;
Thy Brutus bid me give it thee, and I
Will do his bidding. Brutus, come apace,
And see how I regarded Caius Cassius.
By your leave, gods:--this is a Roman's part
Come, Cassius' sword, and find Titinius' heart.    Kills himself      Alarum. Re-enter MESSALA, with BRUTUS, CATO, STRATO, VOLUMNIUS, and LUCILIUS

BRUTUS

Where, where, Messala, doth his body lie?

MESSALA

Lo, yonder, and Titinius mourning it.

BRUTUS

Titinius' face is upward.

CATO

He is slain.

BRUTUS

O Julius Caesar, thou art mighty yet!
Thy spirit walks abroad and turns our swords
In our own proper entrails.     Low alarums

CATO

Brave Titinius!
Look, whether he have not crown'd dead Cassius!

BRUTUS

Are yet two Romans living such as these?
The last of all the Romans, fare thee well!
It is impossible that ever Rome
Should breed thy fellow. Friends, I owe more tears
To this dead man than you shall see me pay.
I shall find time, Cassius, I shall find time.
Come, therefore, and to Thasos send his body:
His funerals shall not be in our camp,
Lest it discomfort us. Lucilius, come;
And come, young Cato; let us to the field.
Labeo and Flavius, set our battles on:
'Tis three o'clock; and, Romans, yet ere night
We shall try fortune in a second fight.    Exeunt

SCENE IV. Another part of the field.     Alarum. Enter fighting, Soldiers of both armies; then BRUTUS, CATO, LUCILIUS, and others

BRUTUS

Yet, countrymen, O, yet hold up your heads!

CATO

What bastard doth not? Who will go with me?
I will proclaim my name about the field:
I am the son of Marcus Cato, ho!
A foe to tyrants, and my country's friend;
I am the son of Marcus Cato, ho!

BRUTUS

And I am Brutus, Marcus Brutus, I;
Brutus, my country's friend; know me for Brutus!    Exit

LUCILIUS

O young and noble Cato, art thou down?
Why, now thou diest as bravely as Titinius;
And mayst be honour'd, being Cato's son.

First Soldier

Yield, or thou diest.

LUCILIUS

Only I yield to die:
There is so much that thou wilt kill me straight;   Offering money

Kill Brutus, and be honour'd in his death.

First Soldier

We must not. A noble prisoner!

Second Soldier

Room, ho! Tell Antony, Brutus is ta'en.

First Soldier

I'll tell the news. Here comes the general.    Enter ANTONY

Brutus is ta'en, Brutus is ta'en, my lord.

ANTONY

Where is he?

LUCILIUS

Safe, Antony; Brutus is safe enough:
I dare assure thee that no enemy
Shall ever take alive the noble Brutus:
The gods defend him from so great a shame!
When you do find him, or alive or dead,
He will be found like Brutus, like himself.

ANTONY

This is not Brutus, friend; but, I assure you,
A prize no less in worth: keep this man safe;
Give him all kindness: I had rather have
Such men my friends than enemies. Go on,
And see whether Brutus be alive or dead;
And bring us word unto Octavius' tent
How everything is chanced.   Exeunt

SCENE V. Another part of the field.Enter BRUTUS, DARDANIUS, CLITUS, STRATO, and VOLUMNIUS

BRUTUS

Come, poor remains of friends, rest on this rock.

CLITUS

Statilius show'd the torch-light, but, my lord,
He came not back: he is or ta'en or slain.

BRUTUS

Sit thee down, Clitus: slaying is the word;
It is a deed in fashion. Hark thee, Clitus.    Whispers

CLITUS

What, I, my lord? No, not for all the world.

BRUTUS

Peace then! no words.

CLITUS

I'll rather kill myself.

BRUTUS

Hark thee, Dardanius.    Whispers

DARDANIUS

Shall I do such a deed?

CLITUS

O Dardanius!

DARDANIUS

O Clitus!

CLITUS

What ill request did Brutus make to thee?

DARDANIUS

To kill him, Clitus. Look, he meditates.

CLITUS

Now is that noble vessel full of grief,
That it runs over even at his eyes.

BRUTUS

Come hither, good Volumnius; list a word.

VOLUMNIUS

What says my lord?

BRUTUS

Why, this, Volumnius:
The ghost of Caesar hath appear'd to me
Two several times by night; at Sardis once,
And, this last night, here in Philippi fields:
I know my hour is come.

VOLUMNIUS

Not so, my lord.

BRUTUS

Nay, I am sure it is, Volumnius.
Thou seest the world, Volumnius, how it goes;
Our enemies have beat us to the pit:      Low alarums

It is more worthy to leap in ourselves,
Than tarry till they push us. Good Volumnius,
Thou know'st that we two went to school together:
Even for that our love of old, I prithee,
Hold thou my sword-hilts, whilst I run on it.

VOLUMNIUS

That's not an office for a friend, my lord.    Alarum still

CLITUS

Fly, fly, my lord; there is no tarrying here.

BRUTUS

Farewell to you; and you; and you, Volumnius.
Strato, thou hast been all this while asleep;
Farewell to thee too, Strato. Countrymen,
My heart doth joy that yet in all my life
I found no man but he was true to me.
I shall have glory by this losing day
More than Octavius and Mark Antony
By this vile conquest shall attain unto.
So fare you well at once; for Brutus' tongue
Hath almost ended his life's history:
Night hangs upon mine eyes; my bones would rest,
That have but labour'd to attain this hour.     Alarum. Cry within, 'Fly, fly, fly!'

CLITUS

Fly, my lord, fly.

BRUTUS

Hence! I will follow.    Exeunt CLITUS, DARDANIUS, and VOLUMNIUS

I prithee, Strato, stay thou by thy lord:
Thou art a fellow of a good respect;
Thy life hath had some smatch of honour in it:
Hold then my sword, and turn away thy face,
While I do run upon it. Wilt thou, Strato?

STRATO

Give me your hand first. Fare you well, my lord.

BRUTUS

Farewell, good Strato.    Runs on his sword

Caesar, now be still:
I kill'd not thee with half so good a will.     Dies    Alarum. Retreat. Enter OCTAVIUS, ANTONY, MESSALA, LUCILIUS, and the army

OCTAVIUS

What man is that?

MESSALA

My master's man. Strato, where is thy master?

STRATO

Free from the bondage you are in, Messala:
The conquerors can but make a fire of him;
For Brutus only overcame himself,
And no man else hath honour by his death.

LUCILIUS

So Brutus should be found. I thank thee, Brutus,
That thou hast proved Lucilius' saying true.

OCTAVIUS

All that served Brutus, I will entertain them.
Fellow, wilt thou bestow thy time with me?

STRATO

Ay, if Messala will prefer me to you.

OCTAVIUS

Do so, good Messala.

MESSALA

How died my master, Strato?

STRATO

I held the sword, and he did run on it.

MESSALA

Octavius, then take him to follow thee,
That did the latest service to my master.

ANTONY

This was the noblest Roman of them all:
All the conspirators save only he
Did that they did in envy of great Caesar;
He only, in a general honest thought
And common good to all, made one of them.
His life was gentle, and the elements
So mix'd in him that Nature might stand up
And say to all the world 'This was a man!'

OCTAVIUS

According to his virtue let us use him,
With all respect and rites of burial.
Within my tent his bones to-night shall lie,
Most like a soldier, order'd honourably.
So call the field to rest; and let's away,
To part the glories of this happy day.Exeunt

Answer these questions in your notes.

1.  Brutus makes two fatal mistakes in Julius Caesar, each stemming from his idealized vision of the assassination and from the image of himself as an "honorable man."  One error occurs in Act II, and one in Act III.  Discuss these errors, and trace the events they set in motion that bring about Brutus's downfall.

2.  The play makes clear that during the Roman Republic, few words inspired such anxiety in the Romans as the word king.  Even thought the last king had been driven out of Rome nearly five centuries before the time of Julius Caesar, the Romans long remembered the evils that their ancestors had experienced under such rule.

a.  Looking back at the portrayal of Julius Caesar in the play, do you think that the anxieties of Brutus and others about Caesar's potential "kingship" were justified?

b.  How do you think Shakespeare's Elizabethan audience, living under a benevolent but absolute monarchy at the time the play was presented, might have regarded this choice between the evils of dictatorship and the evils of anarchy and social chaos?

c.  How would people today feel about this problem of "two evils"?  Which "evil" would people today fear more?

Famous Passages from the Play 
Here are some famous passages of the play.  Read each passage carefully (in its context, if you wish), and answer the questions that follow.

1.  Why, man, he doth bestride the narrow world
     Like a Colossus, and we petty men
     Walk under his huge legs and peep about
     To find ourselves dishonorable graves.
     Men at some time are masters of their fates:
     The fault, dear Brutus, is not in our stars,
     But in ourselves, that we are underlings.
                                      - Act I, Scene 2, lines 135-141 
a.  What simile is central to this passage?
b.  Describe the image it puts in your mind.
c.  Write a paraphrase of the last two lines. 


2.  Let's be sacrificers, but not butchers, Caius.
                                                - Act II, Scene 1, line 166 
a.  What is a "sacrificer"?
b.  What is a "butcher"?
c.  Why does the speaker not wish to be a "butcher"? 


3.  The evil that men do lives after them,
     The good is oft interred with their bones.
                                                - Act III, Scene 2, lines 76-77 
a.  Paraphrase these two lines.
b.  Do you agree with this statement?  Explain. 


4.  There is a tide in the affairs of men
     Which, taken at the flood, leads on to fortune;
     Omitted, all the voyage of their life
     Is bound in shallows and in miseries.
     On such a full sea are we now afloat,
     And we must take the current when it serves,
     Or lose our ventures.
                                              - Act IV, Scene 3, lines 216-222 
a.  Identify the two terms of the central metaphor in this passage.
b.  List all the words that extend the metaphor.
c.  What words are omitted in the third line?
d.  What other words would you substitute for ventures?

Writing

Word Order 
Think about whether the meaning changes when the word order changes in the following pairs of sentences.  If the meaning changes, label the pair C.  If the meaning does not change, label the pair NC.

___ 1.  After the police car came the fire engines.
             The police car came after the fire engines.

___ 2.  After the police car came the fire engines.
             The fire engines came after the police car.

___ 3.  He left the car with ten dollars and the girl.
             He left the girl with the car and ten dollars.

___ 4.  She cut her long hair with the scissors.
             She cut her hair with the long scissors.

___ 5.  Father arrived just as we sat down to dinner.
             Just Father arrived as we sat down to dinner.

___ 6.  Around the corner came the long-distance runners.
             The long-distance runners came around the corner.

Word Order 
Set I:  Add only to each sentence so that the sentence has the meaning given below it.  Use a caret (^) to show where the word should go.  The first one has been done for you.

1.  Ted bought only five goldfish for his little brother.
                              ^
Meaning:  Ted did not buy more than five goldfish.

2.  The teacher gave Bess a spelling test after school. 
Meaning:  All Bess had to do after school was take a spelling test.

3.  The young pilot learned to fly a helicopter. 
Meaning:  The older pilots did not learn to fly the helicopter.

Set II:  Add just to each sentence so that it has the meaning given.

1.  Aunt Carol lent Barbara her red dress. 
Meaning:  Aunt Carol wouldn't lend her both the red dress and the black dress.

2.  The carpenter replaced one board on the porch. 
Meaning: The carpenter did not do anything except replace the one board on the porch.

------------------------------------------------------------

Midpoint and Slope Conjectures 
Surveyors and mapmakers of ancient Egypt, China, Greece, and Rome used various coordinate systems to locate points.  Egyptians in particular made extensive use of square grids and used the first known rectangular coordinates at Saqqara around 2650 B.C.  BY the seventeenth century, the age of European exploration, the need for accurate maps and the development of easy-to-use algebraic symbols gave rise to modern coordinate geometry.  Seventeenth-century French philosopher and mathematician René Descartes (pronounced "day cart") is credited with the development of this new system, which is called Cartesian coordinate geometry.  (Cartesian comes from the Latin form of Descartes's name.)

In algebra you graphed points and lines on the Cartesian coordinate system.  So far in this text you have practiced graphing points in the exercise sets.  In algebra, you were probably given a rule for finding the midpoint of a segment and another rule for finding the slope of a line.  In this lesson you'll rediscover these rules.  If you already know them, the following should help you better understand the rules.  Let's take a look.  

Case 1

Case 2

Find the midpoints of AB and CD.

Find the midpoints of EF and GH.

 

Case 3

In cases 1 and 2, the lines are either horizontal or vertical, therefore the midpoint is not difficult to find.  What if a segment is slanted with respect to the axes and you know only the coordinates of its endpoints?

Estimate the coordinates of the midpoints of IJ and KL.  How would you find the coordinates of the midpoints of any segment without having to graph the segment and estimate the midpoints' coordinates?

Let's look again at Cases 1-3 by completing the statements below.

The endpoint of AB are (1,1) and (5,1).
The endpoint of CD are (3,3) and (-3,3).
The endpoint of EF are (1,-2) and (1,4).
The endpoint of GH are (3,2) and (3,-2).
The endpoint of IJ are (-1,1) and (3,3).
The endpoint of KL are (-1,3) and (5,-1).

   The midpoint of AB is (-?-,-?-).
   The midpoint of CD is (-?-,-?-).
   The midpoint of EF is (-?-,-?-).
   The midpoint of GH is (-?-,-?-).
   The midpoint of IJ is (-?-,-?-).
   The midpoint of KL is (-?-,-?-).

How does the x-coordinate of the midpoint of each segment compare with the x-coordinates of the segment's endpoints?  How does the y-coordinates of the midpoint compare with the y-coordinates of the segment's endpoints?  Are you ready to make a conjecture?  Compare your results with the results of others near you.  State a conjecture and add it to your conjecture list.
If (x1,y1) and (x2,y2) are the coordinates of the endpoints of a segment, then the coordinates of the midpoint are -?- (Coordinate Midpoint Conjecture).

Example A

Example B

Find the midpoint (x,y) of AB with endpoints (-8,13) and (14,7).
x = - 8 + 14 = 6 = 3
            2          2
y = 13 + 7 = 20 = 10
           2          2
The midpoint of AB is (3,10).

Find the missing endpoint (x2,y2) of CD if one endpoint is (3,9) and the midpoint is (0,5). 
0 = (x2 + 3), or x2 + 3 = 0, or x2 = - 3
            2
5 = (y2 + 9), or y2 + 9 = 10, or y2 = 1
            2
The missing endpoint of CD is (- 3,1).

Perhaps the most useful characteristic of a line in the coordinate plane is its slope.  The slope of a line is a measure of its incline or steepness.  The grade  of a road is a measure of its steepness or slope.  The pitch of a roof is a measure of its slope.  The incline of a ramp is a measure of its slope.

If a road rises a vertical distance of 50 meters for every run, or horizontal distance, of 300 meters, then the grade, or slope, of the road is 1/6 and is calculated using the formula below.

slope =  rise =    vertical change      =  50  = 1
             run     horizontal change        300   6

Let's take a closer look at this notion of rise over run for slope.  How would you find another three points that lie on AB
Well, one very clear feature of lines is that they are straight - they never change direction.  Thus you can use the straight pattern of the line to predict other points that the line will pass through.  How?  By noticing how much you go up or down and then over or back to get from one point on a line to another point of the line.  That is the rise over run.  To go from point A to point B on the line at right, you can go up three units and then over two units.  So, to find another point that must be on the line, go up three from point B and over two to a new point.  To find more points, go up three over two, and so on.  Or start from point A and go down three and back two.  The slope of the line is 3/2.  Try the two cases below.

Case 1

Case 2

Find the slope of CD.

Find the slope of EF.

Did you get a slope of 4/7 for CD?

Did you get a slope of - 3/4 for EF?

What if the two points are so far away from each other that counting on the graph to find the rise and run is too difficult?  How can you use the coordinates of the two points to calculate the rise and run, and thus the slope?  For example, what is the slope of GH?  You should get a slope of 23/19.

How can you find the rise from the y-coordinates of the points?  How can you find the run?  State a conjecture and add it to your conjecture list

1.  Without calculating them, determine whether the slope of ABCD, EF,and GH is positive, negative, 0, or undefined.

------------------------------------------------

History

France Underwent Revolutions and Changes of Government 
The Congress of Vienna restored the Bourbon monarch, King Louis XVIII, to the throne of France following Napoleon's exile in 1814.  Louis, glad to be king and unwilling to upset the situation, carried on many of the reforms established between 1789 and 1815.  He retained the Bank of France, the stat-supported schools, and the Napoleonic Code.  He accepted a constitution that limited his power and established a legislature to assist in governing the country.  The constitution gave only the wealthy people the right to vote.

Charles X 
When Louis XVIII died in 1824, his brother Charles X - an ardent believer in absolute monarchy  - succeeded him.  As soon as he became king, Charles antagonized his subjects.  First, he pledged that the government would reimburse the émigrés whose estates had been seized and sold to the peasants.  This unpopular policy meant taxing all the people for the benefit of the emigrant nobles, who had opposed any progress of democracy in France.  Second, Charles abolished most of the liberal provisions of the weak constitution his brother had accepted an tried to restore many features of the Old Regime.

Charles's actions caused trouble in France.  Since 1789 the nation had learned too much about throwing off autocratic rule to accept these changes peacefully.  In July 1830 a revolt spread throughout the country.  Faced with growing hostility, Charles X abdicated.

The successful revolt in France inspired revolutions elsewhere.  Two months after Charles's abdication in 1830, for example, the Belgians declared independence from their Dutch rulers.

Louis Philippe, the "Citizen King" 
The leaders of the French revolt of 1830 wanted to be rid of Charles X, but they could not agree on the kind of government they wanted after his departure.  Those favoring a republic lacked the strength to win.  Finally, they reached a compromise and all groups agreed on the choice of another king.  They selected Louis Philippe, Duke of Orléans, who belonged to a branch of the Bourbon family but had a record of liberal beliefs.

The Revolutions of 1848
In 1848 opposition to the regime of Louis Philippe erupted into violence.  Trouble began over the principle of free speech.  In February opponents of the government organized meetings where they criticized official policy.  Louis Philippe issued a decree prohibiting the final meeting.

The publication of the decree sparked riots in Paris.  The disorders did not seem serious until the National Guard, summoned to restore order, joined the rioters.  The disturbances forced Louis Philippe to abdicate and flee to England.

The people of Paris established a temporary government and proclaimed the Second French Republic in 1848.  (The First Republic had lasted from 1792 until 1804, when Napoleon became emperor.)  The most active group in the new government consisted of the urban working classes, whose leaders believed in socialism.  Because economic depression and widespread unemployment had paralyzed France, the socialist members of the government established "national workshops" to give people work.  This action marked the first appearance in modern times of the idea that the government has a responsibility to remedy chronic unemployment.

Louis Napoleon 
The new constitution written by the National Assembly provided for a republican form of government, with an elected president.  The president would serve a four-year term and would not be eligible for a second term.  The National Assembly would be a single legislative body, consisting of representatives elected by universal manhood suffrage.

In December 1848 the Republic held its first elections.  Instead of electing as president someone who had helped to create the Second Republic, however, the voters overwhelmingly chose Louis Napoleon Bonaparte, the nephew of Napoleon.

Louis Napoleon now employed the plebiscite, a device his uncle had used so successfully.  He asked the French people to permit him to draft a new constitution for the Second French Republic.  Most people believed that he was defending law and order.  They voted almost 12 to 1 in his favor.

The Second French Empire 
The new constitution extended Louis Napoleon's term as president to 10 years.  Although it gave him greater power, he remained dissatisfied.  He wanted to follow in the footsteps of his uncle, Napoleon I - and Napoleon I had been an emperor.

In 1852 Louis Napoleon held another plebiscite for another constitution.  By cleverly manipulating the votes. Louis Napoleon won consent to take the title Emperor Napoleon III.  (He called himself the "third" Napoleon because Napoleon I had had a son.  "Napoleon II" had never reigned and died in 1832.)

Problems in the Crimea and Mexico 
In order to quiet discontent at home, Napoleon III tried to win glory abroad.  The weakening Ottoman Empire gave him his chance.

Because of earlier agreements, Russia claimed the right to protect all Orthodox Christians living under the rule of the Ottoman Turks.  Similarly, France protected the Roman Catholics.  In the 1850s both Russia and France claimed jurisdiction over certain holy places in Palestine, which was part of the Ottoman Empire.  The Ottomans granted privileges to the Roman Catholics but did not do the same for the Orthodox Christians.  The czar demanded these same privileges fort eh Orthodox Christians.  Napoleon III took a firm stand against these Russian demands and formed an alliance with Great Britain, which feared Russian expansion toward the eastern Mediterranean.

The Ottoman Turks, backed by France and Great Britain, resisted Russian claims in the Palestine dispute.  The three allies declared war in March 1854, and full-scale fighting began six months later.  The fighting took place mostly in the Crimea, in southern Russia.

The Franco-Prussian War 
Napoleon III decided to try another bold and risky venture, hoping to regain the support of all groups in France.  At this time Prussia was working to unite all the German states under its leadership.  By opposing this unification, Napoleon could gain support of almost all French people because they distrusted Prussia.

Napoleon really hoped that Prussia would back down and that war would not be necessary.  However, Otto von Bismarck, the head of the Prussian government, had decided that war with France would help to achieve German unification.  Bismarck made a series of clever maneuvers that angered the French, and in July 1870 the French legislature declared war on Prussia.

French Defeat 
From the start of the Franco-Prussian War, the French suffered disastrous defeats.  Napoleon III went to the front to take command of the army, and at the battle of Sedan, he fell into the enemy's hands.

Immediately after the capture of Napoleon III, the Legislative Assembly proclaimed the fall of the Second French Empire and the establishment of a Third Republic.  The new government tried to defend the nation, but Paris fell to the Prussians in January 1871, signifying the end of the war.

France Under German Domination 
Bismarck drew up the Treaty of Frankfort, which dictated harsh terms to France.  France had to give up the territories of Alsace and the eastern part of Lorraine on the French-German border.  It also had to pay a huge indemnity to Germany within three years.  German troops were to occupy northern France until they paid the indemnity.

The Third Republic 
After the fall of Napoleon III, quarreling factions in the National Assembly were unable to agree on a constitution until 1875.  Finally, the assembly passed a group of laws known as the Constitution of 1875, which officially made France a republic.

The Third Republic included a president, elected by the legislature for a term of seven years.  The cabinet of ministers had to approve the president's actions and was responsible for government policy.  Although the constitution did not specifically provide for a premier, or prime minister, the position soon became established.

The Dreyfus case 
The most serious danger to the Third Republic arose in 1894.  An attempt to betray French military secrets to Germany was uncovered.  A court accused and convicted Captain Alfred Dreyfus, a Jewish officer, and sentenced him to life imprisonment.  However, evidence soon came to light indicating that Dreyfus had been falsely convicted.  Even so, the French army command would permit no criticism of its actions.  Monarchists, many Catholics, and anti-Semites - people who dislike Jews - supported the army. 

The real traitor was discovered, but the army cleared him.  Emile Zola, a famous French novelist, wrote an open letter, "J'Accuse" ("I Accuse"), in which he paced blame on the army command and its supporters for this scandal.  Although many responsible for the false charges against Dreyfus confessed, his name was not cleared until 1906.

The Dreyfus case led to a clash between the two major groups in France - those who had condemned Dreyfus and supported the army, and those who supported his cause.

The existence of many different political parties caused political instability in France in the early 1900s.  The parties ranged from the monarchists on the far right to radical socialists on the far left.  Major parties contained a number of "splinter groups," or smaller divisions.  No one party ever completely controlled the French government.  In order to get anything done, parties temporarily united to form coalitions, or political groups organized in support of a common cause.

The Nations of Latin America Gained Independence 
By the early 1800s, the ideologies behind the French Revolution and Napoleonic Wars had strongly affected the political and social thinking of many Europeans.  The people in Spain and Portugal's Latin American colonies were also influenced by these European upheavals.  In addition, the Latin Americans took note of the revolutionary experiences of their neighbor to the north - the United States.  In time, strong independence movements swept the whole region, from Mexico the the tip of South America.

Colonial Society 
Social classes based on privilege divided colonial society.  The highest ranks of society consisted of the royal bureaucrats, the owners of large estates, and the great merchants.  An enormous social gap opened between these classes and the town workers. peasants, and slaves. 
Racial discrimination made the situation in Latin America worse than in Europe.  White people, called peninsulars because they were born in Spain or Portugal, ruled colonial society.  Whites born in the colonies - called creoles - suffered social snobbery and job discrimination at the hands of the peninsulars.

Indians and blacks shared the bottom of the social pyramid.  Many of them did not speak the language of the ruling class.  Furthermore, laws upheld racial distinctions.

By the 1700s people of mixed race became the majority in Latin American society:  Mestizos were of Indian and white background, and mulattoes were od black and white ancestry.  Distribution of mestizos and mulattoes varied considerably.  For example, mestizos became prominent in Mexico, but in Brazil mulattoes became the largest group.  Metizos and mulattoes usually faced social and racial barriers constructed by the peninsulars and creoles.  In the Andes, southern Mexico, and parts of Central America, Indians remained the largest group.

Haiti's Slave Revolution 
By the early 1800s, Spain's American colonies were ripe for revolution.  The first successful revolt, however, took place in the French colony of Haiti, on the island of Hispaniola in the West Indies.

In Haiti a small number of French planters grew sugarcane and coffee trees http://www.trentacademy.com/trentschools/10-12hist1.gifon plantations tended by African slaves.  When the French Revolution broke out, the free mulattoes demanded the same rights as French settlers.  In 1794 the black slave population rebelled.  Mulattoes and blacks united under the leadership of Francois-Dominique Toussaint-Louverture (too.SAN   loo.ver.TOOR), a freed slave, and won control of the island.

Napoleon sent an army to try to reestablish French authority.  The French captured Louverture, and he died a prisoner in France in 1803.  Later, a rebel army defeated the French army and killed or drove out many of the white settlers.  Haiti proclaimed its independence in 1804.

Spanish South America 
Three of the great South American leaders - Simón Bolívar, José de San Martín, and Bernado O'Higgins - had traveled or studied in North America and Europe.  They knew well the ideas of the Enlightenment and the French Revolution.

The first revolt against Spain took place in 1810 in the southernmost viceroyalty of La Plata.  Creole rebels seized control of the government, and six years later, they declared the independence of the United Provinces of La Plata, later named Argentina.  Meanwhile, Paraguay declared its own independence.

In the rest of South America, the struggle turned into a long and bloody civil war led by Simón Bolívar, called "the Liberator" by Latin Americans.  Bolívar started the revolt in this native city of Caracas in 1810.  He did not succeed in destroying Spain's power in the viceroyalty of New Granada until 1819.  Then he raised another army in what is now Venezuela, crossed the Andes, and defeated the Spanish at Boyacá (bah.yuh.CHAY).

Bolívar became president, with almost absolute power, of a new nation called Great Colombia.  The new nation included the present-day countries of Colombia, Venezuela, Ecuador, and Panama.

Meanwhile an Argentine general, José de San Martín, gathered an army and made a difficult crossing of the Andes into the region known as Chile.  He joined forces with the Chileans, led by Bernardo O'Higgins, and overcame Spanish resistance there in 1818.

From Chile, San Martín's forces sailed north to capture the city of Lima in Peru.  The Spanish viceroy fled, and San Martín declared the independence of Peru in 1821.  Royalist forces, however, remained in parts of Peru.  Internal squabbling among the independence leaders led some Peruvians to invite Bolívar to help them defeat the Spanish.  San Martín then withdrew, turning leadership over to the ambitious Bolìvar.

In August 1824 Bolívar won a major victory over the forces led by the Spanish viceroy at Junín (hoo.NEEN) in Peru.  By December of that year, the revolutionaries achieved total victory over the forces loyal to Spain at Ayacucho (eye.uh.KOO.choh).  Peru was free.  In 1825 the northern territory of Upper Peru became a separate republic, named Bolivia in honor of Bolívar.

Brazil 
When Napoleon's army invaded Portugal in 1808, King John VI and his family fled to Brazil.  Once there, John elevated Brazil to a realm equal to Portugal and opened its ports to foreign trade.  Even after the overthrow of Napoleon, King John stayed in Brazil.  In 1820, however, a revolt broke out in Portugal, and the Portuguese persuaded King John to return home.

The Portuguese then tried to return Brazil to the status of a colony.  Angered Brazilian creoles persuaded Pedro, King John's son who had stayed in Brazil, to become ruler of an independent Brazil.  Brazil declared its independence as a constitutional monarchy in 1822, and Pedro I ruled as its emperor until 1831.

The new nations of Brazil and Argentina struggled over territory that lay between them.  patriots in this disputed territory gained independence in 1825, calling their new country Uruguay.

Almost all of Latin America and thus become independent by 1825.  Portugal lost its entire New World empire.  The Spanish lost all their colonies except Cuba and Puerto Rico.  Elsewhere in the region, only a few Caribbean islands, parts of Central America, the Guianas, and the Falkland Islands (Malvinas) remained under colonial rule.

Latin American Unity 
Enormous distances, geographical barriers, and regional rivalries prevented unity among the new Latin American countries.  Of the former Spanish and Portuguese territories, only Brazil managed to maintain national unity.  Ecuador and Venezuela broke away from Great Colombia.  The United Provinces of Central America crumbled into five separate countries, and Argentina was threatened with internal divisions.  By 1840 Latin America contained 17 independent nations. 
In 1826 Bolívar called a congress of the Latin American nations to meet Panama to promote unification.  Only Colombia, Peru, Central America, and Mexico attended.  Although the Panama Congress failed, many Latin Americans cherished the ideal of unity.

-------------------------

 

RNA 
The double helix structure explains how DNA can be replicated, or copied.  However, it does not explain how information is contained in the molecule or how that information is put to good use.  As we will see, DNA contains a set of instructions that are coded in the sequence, or order, of nucleotides.  The first step in decoding that message is to copy part of the sequence into RNA (ribonucleic acid).  RNA is the nucleic acid that acts as a messenger between DNA and the ribosomes and carries out the process by which proteins are made from amino acids.  Ribosomes are the organelles in which proteins are made.

The Structure of RNA 

RNA, like DNA, consists of a long chain of macromolecules made up of nucleotides.  Each nucleotide is made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base.  The alternating sugars and phosphate groups form the backbone of the RNA chain.

There are three major differences between RNA and DNA.  The sugar in RNA is ribose, whereas the sugar in DNA is deoxy-ribose.  Another difference between RNA and DNA is that RNA consists of a single strand of nucleotides, although it can form double-stranded sections by folding back on itself in loops.  DNA, as you will recall, is double-stranded.  Lastly, the nitrogeneous bases found in DNA are adenine, thymine, cytosine, and guanine.  RNA also contains adenine, cytosine, and guanine, but uracil (YOOR-uh-sihl) is present instead of thymine.  Like DNA, RNA follows the base-pairing rules.  Adenine bonds to uracil, and cytosine bonds to guanine.

Although a cell contains many different forms of RNA, there are three main types that are involved in expressing the genetic code.  Each of the three main types of RNA will be discussed later in this section.

In its own way, an RNA molecule is a disposable copy of a segment of DNA.  The ability to copy a DNA base sequence into RNA makes it possible for a specific place on the DNA molecule to produce hundreds or even thousands of RNA molecules with the same informs Dation aNA.

Transcription: RNA Synthesis 
As you will recall, DNA replication is also known as DNA synthesis because the molecule being synthesized turns out to be the same as the molecule being copied.  In RNA synthesis, the molecule being copied is just one of the two strands of a DNA molecule.  Thus the molecule being synthesized is different from the molecule being copied.  The term transcription is used to describe this process.  Transcription is the process by which a molecule of DNA is copied into a complementary strand of RNA.  In other words, transcription is the process of transferring information from DNA to RNA.

Why is it necessary for DNA to transfer its genetic information to RNA?  Recall that DNA is found in the nucleus and ribosomes are located in the cytoplasm.  Because DNA does not leave the nucleus, a messenger, or carrier, must bring the genetic information from the DNA in the nucleus out to the ribosomes in the cytoplasm.  The molecule that performs this function is messenger RNA (mRNA), one of the three main types of RNA.

In order to more fully understand how transcription takes place, we must discuss the role that an enzyme known as RNA polymerase (PAHL-ih-mer-ayz) plays in this process.  An enzyme is specific, that is, it works on only on e substance.  For this reason, part of its name is usually derived from the substance on which it works.  Then the suffix -ase is added.  Thus RNA polymerase works on the polymers RNA and DNA.

During transcription, RNA polymerase attaches to special places on the DNA molecule, separates the two strands of the double helix, and synthesizes a messenger RNA strand.  The messenger RNA strand is complementary to one of the DNA strands.  The base-pairing mechanism ensures that the messenger RNA will be a complementary copy of the DNA strand that serves as its template.

Special sequences in DNA serve as "start signals" and are recognized by RNA polymerase and other proteins associated with transcription.  Other areas on the DNA molecule are recognized as termination sites where RNA polymerase releases the newly synthesized messenger RNA molecules.

Protein Synthesis 
The information that DNA transfers to messenger RNA is in the form of a code.  This code is determined by the way in which the four nitrogenous bases are arranged in DNA.  To understand how the code works, we must answer two questions:  What kind of information is contained in DNA, and how is that information decoded?

The nitrogenous bases in DNA contain information that directs protein synthesis.  Why proteins and not other molecules? you might ask.  The answer can be found in the diversity of things that proteins are capable of doing.  Because most enzymes are proteins, proteins control biochemical pathways within the cell.  Not only do proteins direct the synthesis of lipids, carbohydrates, and nucleotides, but they are also responsible for cell structure and cell movement.  Like the manager of a factory, DNA does not work on the assembly line but can control what the cell factory makes by issuing orders to the organelles (workers).  Together, DNA and its assistant, RNA, are directly responsible for making proteins.  As you can see, DNA and RNA are like nucleic-acid executives who run the entire cell factory.

The Nature of the Genetic Code 
As you will recall, proteins are made by stringing amino acids together to form long chains called polypeptides.  Each polypeptide contains a combination of any or all of the 20 different amino acids.  How, the, can a particular order of nitrogenous bases in DNA and RNA be translated into a particular order of amino acids in a polypeptide?

As you know, DNA and RNA each contain different nitrogenous bases (DNA contains A, T, D, G; RNA contains A, U, C, G); hence, different nucleotides.  For this reason, the genetic code must have a four-letter "alphabet."  In order to code for the 20 different amino acids, more than one nucleotide must make up the code word for each amino acid.  If code words were two nucleotides long, there would be 42, or 16, different code words.  This is not enough for 20 amino acids.  The four nucleotides arranged in triplets, or three, however, produce 43, or 64, different code words.  This is more than enough to produce a different code word for each amino acid.  Therefore, the smallest size for a code word in DNA is three nucleotides.

The code words of the DNA nucleotides are copied onto a strand of messenger RNA.  Each combination of three nucleotides on the messenger RNA is called a codon (KOH-dohn), or three-letter code word.  Each codon specifies a particular amino acid that is to be placed in the polypeptide chain.  It is interesting to note that there is more than one codon for each amino acid.  For example, the amino acid leucine (LOO-seen) has six different codons.  There is also one codon, AUG, that can either specify the amino acid methionine (muh-THIGH-uh-neen) or serve as a starter for the synthesis of a protein.  For this reason, AUG is called an "initiator" codon.  Notice also that there are three "stop" codons.  They do not code for an amino acid.  Instead, these codons act like period at the end of a sentence:  They signify the end of a polypeptide.

First
Base
in
Code
Word

A

Lysine
Lysine
Asparagine
Asparagine

Arginine
Arginine
Serine
Serine

Isoleucine
Methionine
Isoluecine
Isoluecine

Threonine
Threonine
Threonine
Threonine

A
G
U
C

Third
Base
in
Code
Word

G

Glutamic acid
Glutamic acid
Aspartic acid
Aspartic acid

Glycine
Glycine
Glycine
Glycine

Valine
Valine
Valine
Valine

Alanine
Alanine
Alanine
Alanine

A
G
U
C

U

"Stop" codon
"Stop" codon
Tyrosine
Tyrosine

"Stop" codon
Trytophan
Cysteine
Cysteine

Leucine
Leucine
Phenylalanine
Phenylalanine

Serine
Serine
Serine
Serine

A
G
U
C

C

Glutamine
Glutamine
Histidine
Histidine

Arginine
Arginine
Arginine
Arginine

Leucine
Leucine
Leucine
Leucine

Proline
Proline
Proline
Proline

A
G
U
C

 

A

G

U

C

 

Second Base in Code Word

The genetic code consists of 64 codons along with their corresponding amino acids.  These codons are found on messenger RNA.  Of the 64 codons, 61 specify a particular aminohttp://www.trentacademy.com/trentschools/10-12sci3.gif acid.  The other three are stop codons, which signify the end of  polypeptide chain.

Translation 
How does a messenger RNA molecule actually produce a polypeptide?  The decoding of a messenger RNA message into a polypeptide chain )protein) is known as translation.  Translation is an appropriate word for the process because it emphasizes that the message is being translated from the language of nucleic acids into a polypeptide.  The messenger RNA molecule does not produce a polypeptide by itself.  Instead, there is an elaborate mechanism that involves the two other main types of RNA - transfer RNA (tRNA) and ribosomal RNA (rRNA) - and the cytoplasmic organelle known as the ribosome. 
Transfer RNA carries amino acids to the ribosomes, where the amino acids are joined together to form polypeptides.  Transfer RNA is a single strand of RNA that loops back on itself.  There are different transfer RNA molecules 
for each of the 20 amino acids.  Ribosomal RNA makes up the major part of the ribosomes.

The Role of Transfer RNA 
In order to translate the information from a single codon of messenger RNA, such as AUG, we would have to find out which amino acid is coded for by AUG.  The codon AUG codes for the amino acid is methionine.  Methionine is then brought to the polypeptide chain by transfer RNA.

In the drawing at right, you will notice that there are three exposed bases on each transfer RNA molecule.  These nucleotides will base pair with a codon on messenger RNA.  Because the three nucleotides on transfer RNA are complementary to the three nucleotides on messenger RNA, the three transfer RNA nucleotides are called the anticodon. 
Attached to each transfer RNA molecule is the amino acid specified by the codon to which it base pairs.  By matching the transfer RNA anticodon to the messenger RNA codon, the correct amino acid is put into place.  Each transfer RNA acts like a tiny beacon for its specific amino acid.

The Role of Ribosome 
Messenger RNA molecules do not automatically line up transfer RNA molecules and link their amino acids together any more than model airplane parts glue themselves together automatically.  Instead, this process ofp rotein synthesis takes place in organelles known as ribosomes.  Ribosomes are made up of two subunits, a large one and a smaller one.  Each subunit consists of ribosomal RNA and proteins (about 70 different types).

The first part of protein synthesis occurs when the two subunits of the ribosome bind to a molecule of messenger RNA.  Then the initiator codon AUG binds to the first anticodon of transfer RNA, signaling the beginning of a polypeptide chain.  Soon the anticodon of another transfer RNA binds to the next messenger RNA codon.  This second transfer RNA carries the second amino acid that will be placed into the chain of the polypeptide.

As each anticodon and codon bind together, a peptide bond forms between the two amino acids.  A peptide bond is the covalent bond that joins tow amino acids together.  The polypeptide chain continues to grow until the ribosome reaches a stop codon on the messenger RNA. A stop codon is a codon for which no transfer RNA molecule exist.  When the stop codon reaches the ribosome, the ribosome releases the newly formed polypeptide and messenger RNA, completing the process of translation.

As you can now see, the ribosome, in its own way, is at the center of the whole business of making the genetic code work.  In the nucleus, DNA directs the formation of three different kinds of RNA:  transfer RNA, ribosomal RNA, and messenger RNA.  They all leave the nucleus and then seem to go their separate ways.  Despite these different paths, however, they all meet again in the ribosome where protein synthesis takes place.  So the ribosome can be considered the place where a kind of "class reunion" of RNA molecules occurs.  Here each type of RNA molecule plays a role in carrying out the instructions specified in the genetic code.  And the genetic code stores the program for protein synthesis and passes it on from generation to generation.

---

Giovanni Bellini

Born: c. 1426-30, Venice
Died: 1516, Venice

GIOVANNI BELLINI, like his brother Gentile Bellini, began his career as an assistant in the studio of his father, Jacopo Bellini (c. 1400-70). His early work, executed in tempera, reflected a confluence of Byzantine stiffness and the analytical precision of the Flemish. Soon Bellini trained himself to become one of the early masters in the techniques of oil painting. He was later influenced by Donatello (to whose works he was exposed while executing with his father and brother the Pala Gattamelata for the Church of Sant'Antonio da Padova) and by the work of his sister's husband, Andrea Mantegna.

By 1479 Bellini had succeeded his brother in executing a cycle of great historical scenes for the Chamber of the Grand Council [Maggior Consiglio] in the Doge's Palace. Giovanni Bellini's six or seven canvases in the series, acclaimed as among his masterpieces, were destroyed in the devastating Palace fire of 1577.

The theme of Madonna and Child recurs frequently in Bellini's work. Mariolina Olivari comments in Giovanni Bellini [p. 4], "Bellini's paintings are characterized by a strange, subtle tension that always binds the mother and child in a relationship of profound pathos." One of Bellini's most masterful works is the Madonna and Child enthroned with SS. Peter, Catherine, Luisa and Jerome, painted in 1505 when he was approximately 75 years old. The painting is in the Church of S. Zaccaria. Bellini's late work, however, is characterized by highly naturalistic landscapes. 



Madonna and Child

In 1506 Bellini's brother-in-law Andrea Mantegna died after completing only one of a cycle of four paintings commissioned by Cav. Proc. (later Cardinal) Francesco Cornaro (B-60). Thereupon, Cornaro turned to Bellini to execute, with his studio, The Continence of Scipio, perhaps based on a drawing by Mantegna. (See P. F. Brown, Venice and Antiquity [New Haven, 1996], pp. 252-5.) The painter and art historian Giorgio Vasari noted in 1568 that Giorgio Cornaro (presum. H-4, the nephew of Cardinal Cav. Proc. Francesco) had in his colletion at that time another of Giovanni Bellini's paintings, Cena at Emaus; that work, although recorded in an engraving and several derivations by another artist, has not survived.

In The Uffizi: A Guide to the Gallery [Venice: Edizione Storti, 1980, p. 60] Umberto Fortis has noted that "Bellini with his absorption of the achievements of the greatest masters of the age traces the development of Venetian Humanism itself in his own evolution as a painter, to attain a superior, serene autonomy of compositional values."

Bellini trained many younger artists in his workshop, including Giorgione, Titian, Jacopo da Montagna, Rondinello da Ravenna and Benedetto Coda of Ferrara. He was recognized in his own time as the leading painter of his period. Upon visiting Venice in 1506, the German artist Albrecht Durer wrote: "He is the best painter of them all." The prominent writers of his time also joined in his praise, including Pietro Bembo in his verses and Ariosto in Orlando Furioso, Canto 33. In Vasari's words, "There is no lack at Venice of those who endeavored to honor him when dead with sonnets and epigrams, just as he had honored his country when alive."

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