Protein Unit Objectives - Oregon High School



Protein Synthesis Unit Notes

Mrs. Schmit’s Biology Class

By the completion of this unit the learner will be able to:

1. Explain the relationship between DNA, RNA and Protein production.

2. Describe the roles of DNA and RNA in protein synthesis.

3. Model the steps in protein synthesis

4. Compare and contrasts DNA and RNA.

Protein Synthesis Notes

What is protein synthesis?

Flow of Genetic Information:

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DNA holds the code for protein synthesis but ______________________

leave the __________________________

Protein Synthesis is performed at the __________________ in the

_____________________

The cell uses _________________ to _____________ the code from DNA and

________________________ it to the ribosomes.

RNA Structure and Function

I. Ribonucleic Acid Characteristics

a. Bases

b. Simple Sugar –

c. Phosphate

There is no thymine in RNA…… it is replaced with Uracil

II. Structure

a. A nucleic acid backbone

b. ___________ strand

c. Sugar

d.

What are the differences between DNA and RNA?

III. Types of RNA

a. mRNA –

b. rRNA –

c. tRNA –

A. mRNA Function

a. ______________________ DNA code

b. take code ________________________ of nucleus to ribosome

c. give instructions to ribosome _________________________

build a protein .

B. tRNA Function –

d. To deliver _________________ to the ribosome as it is building (synthesizing) _______________.

C. rRNA –

The CODE!! (try to break this code…)

James Watson and Francis Crick, with the help of Rosalind Franklin’s X-ray crystallography images unraveled the structure of DNA:

The fact that bases paired led directly to a theory of how DNA codes for proteins.

It took a few years to determine that the bases spell three-________ “words” called __________

Question:

How many different amino acids are there?

What makes each amino acid different from one another?

PRACTICE:

See the mRNA codon chart. Practice using it.

i. Write the codon for Proline here:

ii. Glycine?

iii. Which amino acid has the most codons?

iv. Which amino acid has the fewest?

v. ______ starts each protein

vi. Three codons tell a __________ to stop making a protein. List them here:

1. What is Transcription?

mRNA synthesis (TRANSCRIPTION – begins with a Promoter on DNA regulates the binding of RNA polymerase and the rate at which transcription takes place)

A mRNA is transcribed (built) using the DNA as a template.

How?

-

-

- Completed when reaches ____________________________________ on DNA – ending transcription.

The original strand is used as the template.

Result: The resulting mRNA looks exactly like the _______ strand of the DNA, with one important distinction each T is replace with a ____.

a. RNA releases from DNA and is __________ before leaving the _______________.

Result is a mRNA molecule

PRACTICE

DNA Strand : A T C G A T G C A T C G

RNA Strand: ______________________________

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1. What is Translation?

How does it happen?

i. mRNA _____________________ and heads to the ________________ where the _________________________ are located.

a. Ribosomes are where _____________________________ occur

b. Each sequence of nucleotides is a _____________. Each codon codes for a specific ____________________________________.

ii. ____________ ______________ are brought to the ribosome by tRNA.

c. There are ________ different _______________ molecules, one for each type of amino acid.

d. tRNA ______________ finds their ________________________ codon on mRNA.

Anticodon – 3 letters found to match the mRNA’s codon.

mRNA codon: UAA CGA GGC

tRNA anticodon: AUU

iii. ___________________ bonds form between the amino acids forming a ______________________.

iv. ______________ stops when a stop codon is reached

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Label the following diagram:

• Original strand (blue)

• Copy strand (template for RNA) (red)

• The mRNA (orange)

• Nucleus

• Nuclear Membrane (black)

• 5’ and 3’ ends of each molecule

• All amino acids (green)

• All missing bases

• Ribosome (brown)

• The next tRNA to be used (yellow)

• Transcription & Translation

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1. Where does transcription take place?

2. Where does translation take place?

3. What does transcription make?

4. What does translation make?

Hint: transcription means “re-write” in the same language [A,T,G,C,U]

translation is changing from one language [A,T,G,C,U]to another [Met-Ala-Glu-etc.]

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