6.1 Gene Expression (CQ - exam)

Question 1

why it is advantageous for a cell to synthesize mRNA?

Answer 1

It is advantageous for a cell to synthesize mRNA because the genetic code are interpreted through the mRNA, not DNA. They hold information of how to make proteins.

Question 2

triplet hypothesis

Answer 2

proposes the idea that genetic coding is read 3 nucleotides bases at a time. Codons is the name for the 3 nucleotides that code for amino acids. This hypothesis was proven by Crick and Brenner in 1961.

Question 3

3 characteristics of the genetic code

Answer 3

1. Redundant: +1 codon codes for the same amino acid
2. Continuous: knowing where to start and end protein synthesis
3. Nearly universal: almost all organisms use the genetic code table to synthesize proteins

Question 4

Why do all growing polypeptides begin with methionine (Met)?

Answer 4

All growing polypeptides begin with methionine because it is the start codon required for beginning translation.