36. Genetic code - definition and characteristics.

Question 1

Genetic code is the collection of codons that specify all the amino acids found in proteins. A codon is a sequence of 3 bases (triplet code) in mRNA that specifies a particular amino acid.

Answer 1

Genetic code is the collection of codons that specify all the amino acids found in proteins. A codon is a sequence of 3 bases (triplet code) in mRNA that specifies a particular amino acid.

Question 2

The successive codons determine the sequence in which amino acids add to the growing polypeptide chain.

Answer 2

The successive codons determine the sequence in which amino acids add to the growing polypeptide chain.

Question 3

There are 4 bases .’. 4^3 = 64 codons which code for 20 different amino acids. (include 3 stop codons)

Answer 3

There are 4 bases .’. 4^3 = 64 codons which code for 20 different amino acids. (include 3 stop codons)

Question 4

It’s degenerate - a single amino acid may be coded for by more than one codon Non-overlapping - a single nucleotide cannot be part of 2 adjacent codons
Start codon: AUG and Stop codon: UAG, UAA or UGA in RNA and TAG, TAA or TGA in DNA

Nearly universal - the same codon specifies the same amino acid in almost all species

Answer 4

It’s degenerate - a single amino acid may be coded for by more than one codon Non-overlapping - a single nucleotide cannot be part of 2 adjacent codons
Start codon: AUG and Stop codon: UAG, UAA or UGA in RNA and TAG, TAA or TGA in DNA

Nearly universal - the same codon specifies the same amino acid in almost all species