Chapter 40: Protein Synthesis

Question 1

What is a codon?

Answer 1

Series of 3 nucleotides on the mRNA that holds instructions for making a protein

Question 2

Each codon signifies a ___, ____, or an _____

Answer 2

Start, Stop, or Amino Acid

Question 3

Process by which mRNA code is read and converted into a specific amino acid sequence (protein)

Answer 3

Translation

Question 4

What are the 3 key players in translation?

Answer 4

Ribosomes, mRNA, and tRNA

Question 5

Ribosomes are made up of ___

Answer 5

rRNA + proteins

Question 6

What is the role of mRNA?

Answer 6

Carries coded instructions for protein synthesis (translation)
Travels from DNA in nucleus to ribosome in the cytoplasm

Question 7

What is the role of tRNA?

Answer 7

Brings AA to the ribosome so it can build proteins

Question 8

tRNA has ____

Answer 8

Anticodons

Question 9

Anticodons are ____

Answer 9

3 nucleotide sequence in tRNA that is complementary to the mRNA codon. Base pair is then formed

Question 10

What are the two main properties of tRNA?

Answer 10

1) has an anticodon that can base-pair with a codon

2) has a site that binds to the kind of AA specified by the codon

Question 11

rRNA makes up ____.

Answer 11

Ribosomes

Question 12

Ribosomes contain more ____ than ____

RNA than protein.

Answer 12

Ribosomal proteins decorate the surface of the ribosome. Ribosomes are mainly rRNAs, but decorated with proteins

Question 13

Ribosomes are made up of two subunits, large and small. The large subunit contains 3 types of sites - what are they?

Answer 13

A site - Aminoacyl-tRNA binding site - acceptor site
P site - Peptidyl-tRNA binding site
E site - Exit site

Question 14

What is the function of the small subunit of the ribosome?

Answer 14

mRNA binding site

Question 15

Where does protein synthesis take place?

Answer 15

Ribosome

Question 16

In E. coli, the ribosome sediments at 70S and is made of two subunits, the large ____ subunit and the small ____ subunit.

Answer 16

Large - 50S
Small - 30S

This setup applies to prokaryotic/mitochondrial as well

Question 17

For eukaryotic organisms, the ribosome is ____ and has a large subunit of ___ and a small subunit of ____.

Answer 17

Ribosome - 80S
Large - 60S
Small - 40 S

Question 18

Ribosomes are RNA-protein supramolecular complexes. They are the ____ abundant type of RNA-protein complex in cells.

Answer 18

Most

Question 19

Although proteins outnumber rRNAs, rRNAs comprise ____ of the ribosomal mass

Answer 19

60%

Question 20

First step in making protein is for the mRNA to more from the _____, through the ____ to the _____

Answer 20

From nucleus, through cytoplasm, to ribosome

Question 21

What is the start codon on mRNA that signals beginning of protein?

Answer 21

AUG

Question 22

What are the 3 steps in translation?

Answer 22

Initiation, Elongation, Termination

Question 23

mRNA is ______ in the nucleus

Answer 23

TransCRIBED

Question 24

Once mRNA moves into cytoplasm, a _____ attaches itself to the mRNA molecule

Answer 24

Ribosome

Question 25

Next a _____ molecule arrives, bringing a specific _____

Answer 25

tRNA

Amino Acid

Question 26

tRNA brings the specific AA to the first ___ bases (codon) on the mRNA

Answer 26

3

Question 27

The 3 unpaired bases (_____) on the tRNA link up with the codon

Answer 27

Anticodon

Question 28

Another tRNA molecules comes into place, bringing a second AA. The anticodon links with the second codon on the _____

Answer 28

mRNA

Question 29

A _____ forms between the two amino acids

Answer 29

Peptide bond

Question 30

The first tRNA molecule ____ its AA and moves off into the cytoplasm

Answer 30

Releases

Question 31

The peptide bonds formed between the AA grow to from a ___

Answer 31

Polypeptide chain

Question 32

Translation continues until a _____ codon is reached

Answer 32

Termination/Stop

Question 33

The ____ mRNA may be used to make many copies of the same protein

Answer 33

Same