Lecture 16 - Genetic Code and Translation

Question 1

What is the one gene, one enzyme hypothesis?
What early experiment supported this?

L16 S5;7-8

Answer 1

Each gene was responsible for producing only one polypeptide.

The Beadle and Tatum experiment using Neurospora with mutated genes for amino acid synthesis on minimal medium.

Question 2

Define degenerate code, synonymous codons, and isoaccepting tRNAs.

L16 S23

Answer 2

Degenerate code:
-an amino acid can be specified by more than one codon

Synonymous codons:
-codons that specify the same amino acid

Isoaccepting tRNAs:
-tRNAs that accept the same amino acid but have different anticondons

Question 3

What is the wobble hypothesis?

L16 S25-26

Answer 3

The first and second positions in the codon follow normal base pairing, however there is some variability in base pairing in the third position

Question 4

How do aminoacyl-tRNA synthetases recognize what amino acid is paired with which tRNA?

L16 S34

Answer 4

Each tRNA has certain locations that contain a unique set of bases that specify only one amino acid.

Question 5

What is the Kozak sequence?

L16 S38

Answer 5

Consensus sequence that includes the start codon, AUG, and indicates that that AUG is the one indicating to start protein synthesis.