U3A1: 2A relationship between nucleic acids + proteins

Question 1

proteome

Answer 1

complete set of proteins expressed by a genome.

Question 2

biomacromolecule

Answer 2

large, complex structures crucial to the functioning and development of all living organisms. includes lipids, polysaccharides, nucleic acids and polypeptides.

Question 3

8 functions of proteins

Answer 3

• enzymes (speed up chemical reactions)
• transport (entry + exit of substances from cells)
• structural (supports cell and tissue shape)
• hormones (communication, inducing change) and receptors (recieving environmental signals)
• defence (recognition + destruction of pathogens)
• motor (muscle movement)
• storage (reserve for molecules in organisms)

Question 4

structure of an amino acid

Answer 4

• central carbon
• hydrogen atom
• amino group
• carboxyl group
• r-group

Question 5

role of the r-group in an amino acid

Answer 5

each amino acid has it’s own specific r-group. therefore the r-group uniquely determines the identity of a particular amino acid.

Question 6

condensation polymerisation

Answer 6

process in which a polymer is formed via a condensation reaction. seperate monomers (amino acids) undergo a condensation reaction, forming a polymer (polypeptide chain) and releasing water as a by-product.

Question 7

primary protein structure

Answer 7

sequence of amino acids in a polypeptide chain. each amino acid is held via peptide bonds.

Question 8

secondary protein structure

Answer 8

polypeptide chain folds + coils by forming hydrogen bonds between amino acids of different sections.

• alpha-helices: helix shape caused by repulsion between equally charged side chains.
• beta-pleated sheets: polypeptide lengths line up (can be parallel or antiparallel) forming a sheet.
• random coils: irregular structures (join alpha helices and beta-pleated sheets).

Question 9

tertiary protein structure

Answer 9

polypeptides are folded into their 3D shape by other proteins, and held in position by hydrogen bonds. it is at this structure that proteins may become functional.

Question 10

quarternary protein structure

Answer 10

2 or more tertiary proteins structures join together.