LEC 9 PROTEIN SYNTHESIS

Question 1

What’s is protein synthesis?

Answer 1

Making protein from DNA via RNA

Question 2

The production of protein from specific gene is called?

Answer 2

Gene expression

Question 3

What are the two stages of protein synthesis?

Answer 3

Transcription & Translation

Question 4

What happens during ‘transcription’?

Answer 4

Specific code from gene create mRNA

DNA&raquo_space; mRNA

Question 5

What happens during ‘Translation’?

Answer 5

Ribosomes reads code from mRNA and make protein (polypeptide chain)

mRNA&raquo_space; Protein

Question 6

Whats the bases of the FIRST codon?

Answer 6

AUG

(Chain always starts with AUG)

Question 7

What are ‘introns’?

Answer 7

Non-coding region of gene - No amino acids

(Non-specific information)

Question 8

What are ‘Exons’?

Answer 8

Coding region of gene

(Specific information)

Question 9

T/F
Exons are taken by mRNA and introns are removed

Answer 9

TRUE

(specific information taken by mRNA - make protein)

Question 10

Define ‘Genetic code’?

Answer 10

List of ‘Amino acid’ & matching ‘mRNA codons’

Question 11

Which condon is alway the START codon?

Answer 11

AUG (Methionine)

Chain always start with

Question 12

List the three (3) STOP codons?

Answer 12

UAA
UAG
UGA

Question 13

T/F
Stop codons does not encode for amino acid

Answer 13

TRUE

Question 14

Transcription of the gene occurs in the nucleus with an enzyme called?

Answer 14

RNA polymerase

Question 15

RNA copy is called?

Answer 15

mRNA

Question 16

What are the 3 steps to transcription?

Answer 16

Initiation, Elongation & Termination

Question 17

Explain initiation? (1st step)

Answer 17

1. Transcription factors binds to > promoter
2. RNA polymerase binds to > promoter >DNA unwind

Question 18

Explain Elongation? (2nd step)

Answer 18

RNA polymerase builds> mRNA transcript

Double helix formed

Question 19

Explain Termination?

Answer 19

End of gene > mRNA transcript released

Production stops

Question 20

If information translation goes wrong, what’s the result?

Answer 20

Abnormal cells produce > Cancer

Question 21

Is the Statement TRUE or FALSE?

Introns - Remove
Exons - Spliced together

Answer 21

TRUE

Question 22

Where does Translation occur?

Answer 22

Cytosol (cytoplasm)

(mRNA exit nucleus )

Question 23

mRNA information/coding is translated into___?

Answer 23

Amino acids

Question 24

mRNA is translated by____ &____?

Answer 24

Ribosome & tRNA

(mRNA only reads ribosomes)

Question 25

What’s the function of ribosomes?

Answer 25

Protein synthesis Site

(Reads code from mRNA to make protein)

Question 26

Name the 2 subunits of Ribosomes

Answer 26

Large subunit- tRNA -anticodon

Small subunit- mRNA-codon

Codon > Anticodon

Question 27

What are the three (3) binding sites of ribosomes?

Answer 27

A, P & E

Question 28

What is bonded to the A site, P site and E site?

Answer 28

A site - Binds incoming tRNA

P site - Amino acid added to protein

E site - tRNA exit

Question 29

What is Transfer RNA?

Answer 29

Link between mRNA and amino acid > produce protein

Note:
tRNA make and release amino acid then return to make more

Question 30

What is located at the top and bottom ends of tRNA?

2. What are anticodons?

Answer 30

T- Amino acid
B- anticodons

2. tRNA 3 nucleotides - match mRNA codon

Question 31

What are three (3) stages of translation?

Answer 31

Initiation, Elongation and Termination

Question 32

What happens during initiation?

Answer 32

tRNA binds to mRNA

Question 33

What happens during Elongation?

Answer 33

Amino acid linked - peptide bond
Chain gets longer

(Amino acids joined)

Question 34

What happens during termination?

Answer 34

-Ribosome reaches STOP CODON
(UAG, UAA or UGA)

-Release factor binds to stop codon

• Translation ENDS

Question 35

What is the end product of the translation stages?

Answer 35

Polypeptide chain
(Protein chain)

Question 36

Post translational modification

Answer 36

Polypeptides destined:
Cytocol < Free ribosome

Organelle < Bound ribosome- RER

Question 37

START AND STOP CODONS
(MEMORIZE)

Answer 37

Start: AUG
Stop: UAA, UAG & UGA