Amino acids and proteins

Question 1

amino acid structure

Answer 1

H H O
\ | //
N – C – C amino group, R group and
carboxylic group
/ | \
H R OH

Question 2

what bond joins amino acids

Answer 2

peptide bond

Question 3

what reactions join and break amino acids

Answer 3

condensation and hydrolysis

Question 4

primary structure of amino acids

Answer 4

the sequence of amino acids in a polypeptide chain

Question 5

secondary structure of an amino acid

Answer 5

alpha helix spiral spring held by hydrogen bonds or parallel chains of a beta pleated sheet held by hydrogen bonds

Question 6

tertiary structure of an amino acid

Answer 6

the folding of a protein into its overall 3D shape which is determined by the location of R groups. the bonds which hold the tertiary structure are disulphide bonds, ionic bonds, hydrogen bonds and hydrophilic/ hydrophobic interactions.

Question 7

example of a tertiary protein

Answer 7

enzymes which can be denatured by heat or pH

Question 8

quaternary structure of a protien

Answer 8

complex protein, two or more polypeptide chains curl together. the chains are held together by hydrogen, ionic, disulphide bonds and hydrophobic interactions

Question 9

example of quaternary protein

Answer 9

haemoglobin

Question 10

collagen

Answer 10

a fibrous protein made of 3 parallel polypeptide molecules wound together. each fibre is cross-linked with other fibres to produce a moleculeh with great strength. collagen is strong and insoluble in water so metabolically active

Question 11

haemoglobin

Answer 11

a globular protein