L7 - Introduction to Protein Structure and Function Flashcards
List and describe the four levels of protein structure
- primary
- The amino acid sequence determined by RNA transcript - secondary
- Display Alpha helices and beta strands/sheet - tertiary
- 3D folded protein structure - quaternary
- Association of multiple folded peptide chains into a larger complex
what is the common structure of amino acids
Amino acids consist of an alpha carbon bonded to a carboxyl group (-COOH),
amino group (NH2) and side chain (R-group
what is the common structure of peptide chain
Peptide bond formed by dehydration of two residues to form a peptide backbone of one nitrogen group and two carbon groups
types of physical and chemical properties of amino acid side chains
Physical properties: Size and Shape
Chemical properties: Charged, uncharged, basic, acidic.
how do the physical and chemical properties influence the folding of the peptide chain
the attraction and repulsion of the side chain characteristics to each other form the specialised shapes of proteins as the proteins attempt to pack due to size and shape efficiently.
what interactions determine or stabilise the secondary and tertiary structure
Folding is driven by attainment of lowest energy state
Folding determined by hydrophobic effect and stabilised by hydrogen bonding interactions
Describe how primary structure relates to secondary and tertiary structure
Primary structure determines the folding of proteins into 2nd and 3rd structures based on the psychical and chemical properties of the AA
Describe how tertiary structure determines the protein function
Define a protein domain
Are distinct units of a protein that are stably folded independently from the rest of the protein. Domains often confer a particular function or interaction which contributes to the overall function of the protein.
