proteins

Question 1

give 3 examples of natural polymers

Answer 1

proteins

polysaccharides

nucleic acids

Question 2

what is the role of proteins in animals

Answer 2

provide structural material in animal cells and act as catalysts (enzymes) for biochemical processes

Question 3

how are peptides made

Answer 3

by linking amino acids during a condensation reaction

Question 4

what is an amide/peptide link

Answer 4

CON

Question 5

define protein

Answer 5

sequence of amino acids joined by a peptide link

formation is catalysed by a peptidase enzyme

Question 6

what is the primary structure of a protein

Answer 6

sequence of amino acids

Question 7

what is the secondary structure of a protein

Answer 7

amino acids in chain may hydrogen bond with amino a/a forming alpha helix or beta pleated sheets

Question 8

give the location of the N-H bonds in alpha helix

Answer 8

in alpha helix (alpha helicases) N - H bonds in amino acids are on the same side of protein chain

Question 9

give the location of the N - H and C= O bonds in beta pleated sheets

Answer 9

N - H and C = O alternate from one side of the protein chain to the other

Question 10

what is the tertiary structure of a polypeptide

Answer 10

polypeptide arranges into 3d helix or b pleated sheets

held in place by H bonding, ionic interactions, sulfur - sulfur bonds

Question 11

what are disulfide bridges

Answer 11

bonds between 2 cystenine R groups

disulfide bridges = strong covalent bonds

disulfide bridges are therefore stronger than H bonds

Question 12

what is the quaternary structure of a protein

Answer 12

arrangement of protein made from more than 1 polypeptide chain

Question 13

how can 3D structure of a protein be determined

Answer 13

x - ray diffraction

(locates the position of the atoms in space)