4A.2 Genes & Chromosomes

4A.2 Genes & Chromosomes

Genes

• Contained in DNA.
• Sequence of DNA bases that code for either a polypeptide or a functional RNA (RNA other than mRNA that performs a special task during protein synrthesis).
• Sequence of amino acids in a polypeptide forms the primary structure - different order & number of bases determines different order of amino acids.
• Each amino acid is coded for by a sequence of three bases (codon).
• To make a polypeptide, DNA is first copied into mRNA (1st stage of protein synthesis)
• Genes that don't code for a polypeptide, code for functional RNA (tRNA or rRNA - part of ribosomes)
• Complete set of…