Gentic Control Of Protein Stucture And Function

Question 1

What is a codon?

Answer 1

A sequence of three nucleotide based on mRNA that codes for a single amino acid.

Question 2

What is a stop codon?

Answer 2

A codon that doesn’t code for any amino acids but marks the end of a polypeptide chain much like a full stop marks the end of a sentence.

Question 3

How many polypeptide chains does DNA, mRNA and tRNA contain?

Answer 3

DNA- 2
mRNA-1
tRNA- 1

Question 4

Order DNA, mRNA and tRNA in terms of size of the molecule.

Answer 4

DNA largest
mRNA smaller than DNA but larger than mRNA
tRNA is the smallest molecule of the three

Question 5

What is the structure of DNA, mRNA and tRNA?

Answer 5

DNA is a double helix
mRNA is a single helix
tRNA is a clover shape

Question 6

What are the organic bases in DNA, mRNA and tRNA?

Answer 6

DNA -ATGC
mRNA- AUGC
tRNA- AUGC

Question 7

Name all the organic bases.

Answer 7

Adenine
Thymine in DNA /uracil in RNA
Guanine
Cytosine

Question 8

Where is DNA, mRNA and tRNA found?

Answer 8

DNA is mostly found in the nucleus
mRNA is manufactured in the nucleus but found throughout the cell
tRNA is manufactured in the nucleus but found throughout the cell

Question 9

What is the stability of DNA, mRNA and tRNA?

Answer 9

DNA - very stable
mRNA - chemically unstable (easily broken)
tRNA - chemically more stable than mRNA but less stable than DNA

Question 10

What is an anticodon?

Answer 10

Part of tRNA that binds to a codon on the mRNA strand with complementary base pairs.

Question 11

Describe the transcription process.

Answer 11

1. The enzyme DNA helicase acts on a specific region of the DNA to break the hydrogen bonds so the two stands separate and expose the nucleotide bases
2. The enzyme DNA polymerase moves in and binds the free nucleotides from the pool of them in the nucleus.

Question 12

What is a degenerate code?

Answer 12

An amino acid that is coded for my more than one codon. More than one codon codes for the same amino acid.