Gene Expression 1.3

Question 1

At the ribosome, amino acids are linked by…

Answer 1

Peptide bonds to form polypeptides.

Question 2

Polypeptides can fold to give a ….

Answer 2

3D structure

Question 3

Polypeptide structures are held together by

Answer 3

Hydrogen bonds

Question 4

Amino acids can be separated and identified using…

Answer 4

Chromatography

Question 5

What is the laboratory method used to separate mixtures

Answer 5

Gel electrophoresis

Question 6

What is RNA

Answer 6

Ribonucleic acid
Made of nucleotide subunits
Single stranded

Question 7

What base replaces Thymine in RNA

Answer 7

Uracil

Question 8

Function of mRNA

Answer 8

Formed in the nucleus, from free nucleotides. Transcribed from DNA.
mRNA carries a copy of the DNA code from the nucleus to the ribosome in the cytoplasm.

Question 9

What is the name of the bases that are ‘read’ at the ribosome?

Answer 9

Codon

Question 10

Function of tRNA

Answer 10

tRNA molecules carry specific amino acids, bringing the, to the ribosome to build proteins

Question 11

What are the three bases exposed on the tRNA called?

Answer 11

Anticodon

Question 12

Where do amino acids attach

Answer 12

To the tRNA amino acid attachment site

Question 13

What is rRN

Answer 13

rRNA molecules combine with proteins to form the ribosome

Question 14

What is the phenotype of an organism determined by?

Answer 14

The proteins produced as a result of gene expression. (Also influenced by environmental factors)

Question 15

Where does transcription start

Answer 15

A region of DNA known as the promoter

Question 16

What is the enzyme responsible for transcription

Answer 16

RNA polymerase

Question 17

What does RNA polymerase do

Answer 17

It binds at the promoter and moves along DMA to unwind the double helix. It also breaks the hydrogen bonds between bases.

Question 18

What happens after RNA polymerase has separated DNA.

Answer 18

RNA nucleotides align with their complementary base partner on the template strand and form a primary transcript of mRNA

Question 19

Where does the primary transcript gp

Answer 19

Enters the cytoplasm

Question 20

What are non-coding regions called

Answer 20

Introns

Question 21

What are coding regions called

Answer 21

Exons

Question 22

What is RNA splicing

Answer 22

After the mRNA has been transcribed the intones are removed and the remaining exons are spliced together (order unchanged)

Question 23

What is the transcript called when the exons have been spliced togther

Answer 23

The mature transcript

Question 24

What is Translation

Answer 24

The synthesis of a polypeptide following the code within the mature mRNA transcript

Question 25

What is the translation process

Answer 25

1. Initiated by a start codon on the mRNA strand
2. tRNA molecules become attached to specific amino acids in cytoplasm and transport them to ribosome.
3. The 1st tRNA molecule moves to the ribosome by means of base pairing between the anticodon on the tRNA and the complementary codon on the mRNA strand.
4. Step 3 repeats until a stop codon is reached
5. The amino acids are joined by peptide bonds forming a polypeptide chain

Question 26

Alternative Splicing

Answer 26

Alternative RNA segments treated as introns and exons