Protien Synthesis

Transcription

Process of copying the genetic information in a molecule of DNA into a complementary strand of mRNA

Translation

Process by which a sequence of bases in mRNA is converted into a sequence of amino acids in a polypeptide.

Features of Genetic Code

• It’s a three letter code - triplet

• The code is universal. Each triplet codes for the same amino acids in all living things

• The code has punctuations. 3 of the DNA triplets act as full stops, while others act as start signals

• Is redundant/degenerate meaning some amino acids are coded for by more than one triplet

Codon

A sequence of three bases on an mRNA molecule that codes for a specific amino acid or for a stop signal

Anticodon

Sequence of three unpaired bases on a tRNA molecule that binds with a codon on mRNA

Gene mutations

A change in the base sequence in a part of DNA

Types of Mutations

Substitution - a base is replaced by a different base

Deletion - a base is lost and not replaced

Insertion - a base is added

Frame- shift mutation

A type of mustation caused by insertion or deletion of on or more nucleotides, resulting in incorrect reading of the sequence of triplets in the genetic code due to the shift in reading frame.