proteins

Question 1

biological roles of protein

Answer 1

structural
catalytic
signalling
immunological

Question 2

structure of an amino acid

Answer 2

C, H, O, N and S

Question 3

R-group

Answer 3

complex ring structures
R-group determines the amino acid
Can be polar / non-polar / hydrophobic / hydrophilic

Question 4

Amino acids

Answer 4

Twenty different amino acids are found in cells.
Five of them are said to be non-essential as our bodies can make them from other amino acids

Nine are essential and must be obtained from foods we eat.

Six are conditionally essential as they are only required by infants and growing children.

Question 5

Amino Acids as Buffers

Answer 5

in water the amino group and carboxyl groups can ionise

NH2 can become NH3+ and COOH an become COO-

molecule has acidic and basic properties (amphoteric)

By accepting and releasing H+ ions, amino
acids can regulate changes in pH which
means they behave as pH buffers

Question 6

protein elements

Answer 6

carbon, hydrogen, oxygen and nitrogen

Question 6

peptides

Answer 6

combined amino acid (monomers) form peptide (polymers)

Question 7

Peptide Bonds

Answer 7

Two amino acids come together to form a dipeptide, linked by a peptide bond which is a covalent bond.

condensation reaction