1- proteins

Question 1

amino acids contain:

Answer 1

• an amino group (NH2)
• a carbonyl group (COOH)
• a variable R group

Question 2

how many different amino acids are there?

Answer 2

20

Question 3

what does the R group determine?

Answer 3

the chemical properties of the amino acids

Question 4

draw an amino acid

Answer 4

Question 5

peptide

Answer 5

a component consisting of two or more amino acids linked in a chain

Question 6

polypeptide

Answer 6

linear, unbranched chain of amino acids, which forms as part of a protein molecule

Question 7

protein

Answer 7

a molecule consisting of one singular or multiple polypeptides

Question 8

amino acids are joined by

Answer 8

peptide bonds formed in condensation reactions

Question 9

secondary structure of proteins contain

Answer 9

hydrogen bonds

Question 10

what is the shape of the tertiary structure of a protein determined by?

Answer 10

the type of bond present

Question 11

types of bonds that could be present in tertiary structure

Answer 11

• hydrogen bonds
• ionic bonds- salt bridges, formed between oppositely charged groups on the R groups
• disulphide bridges- covalent bonds between sulphur atoms in cysteine
• weak hydrophobic interacfions- clustering of hydrophobic R groups away from water

Question 12

primary structure of a protein

Answer 12

the linear sequence of amino acids in the polypeptide chain

Question 13

secondary structure

Answer 13

the folding of polypeptide chains into an alpha helix or beta pleated sheet

Question 14

tertiary structure

Answer 14

the 3D folding of the secondary structure into a complex shape. this is formed due to side chain interactions between R groups, after translation.

Question 15

quaternary structure

Answer 15

the 3D arrangement of more than 1 polypeptide

Question 16

fibrous vs globular proteins

Answer 16

Question 17

collagen vs haemoglobin

Answer 17

Question 18

conjugated protein

Answer 18

a protein to which another non-protein chemical group is attached