Protein Function

Question 1

what determines protein structure

Answer 1

• amino acid sequence

Question 2

what determines protein function

Answer 2

amino acids exposed on exterior of final 3D protein structure (side chains)

Question 3

why are amino acids unique

Answer 3

• chemical reactivity allows it to act as enzymes, structural support, receptors, motors

Question 4

briefly define an enzyme

Answer 4

powerful and highly specific catalysts

Question 5

where does protein-ligand interaction occur

Answer 5

at binding site

Question 6

what does binding selectivity of a protein need

Answer 6

many weak non-covalent bonds occurring at the same time
- van der waals
- hydrogen bonding (weaker than covalent)
- electrostatic attractions

Question 7

how are the binding sites of antibodies versatile

Answer 7

• they can make binding sites that bind tightly and very particularly to invading foreign bodies

Question 8

describe antigen protein structure

Answer 8

• y-shaped
• 4 chains (H+L)
• 2 variable areas (VL + VH)
• length and sequence of loops differ

Question 9

name the common functional classes of enzymes

Answer 9

hydrolase, nuclease, protease, synthase, isomerase, polymerase, kinase, phosphatase, oxido-reductase, ATPase

Question 10

what is the biochemical function of hydrolase

Answer 10

catalysis of hydrolytic cleavage reaction

Question 10

what is the biochemical function of nuclease

Answer 10

breaks down nucleic acid by hydrolyzing bonds between nucleotides

Question 11

what is the biochemical function of protease

Answer 11

breaks down proteins by hydrolyzing peptide bonds between amino acids

Question 12

what is the biochemical function of synthase

Answer 12

synthesis of molecules in anabolic reactions by condensing 2 molecules together

Question 13

what is the biochemical function of isomerase

Answer 13

catalysis rearrangement of bonds within a single molecule

Question 14

what is the biochemical function of polymerase

Answer 14

catalysis of polymerization reactions such as the synthesis of DNA and RNA

Question 15

what is the biochemical function of kinase

Answer 15

catalyzes the addition of phosphate groups to molecules

Question 16

what is the biochemical function of phosphatase

Answer 16

catalyzes the hydrolytic removal of a phosphate group from a molecule

Question 17

what is the biochemical function of oxido-reductase

Answer 17

catalyze reactions where one molecule is oxidized and the other is reduced
- can also be called oxidases, reductases, dehydrogenases

Question 18

what is the biochemical function of ATPase

Answer 18

hydrolysis of ATP

Question 19

what does the name of an enzyme tell us

Answer 19

• substrate
• nature of reaction catalyzed

Question 20

what is the purpose of lysozyme, examples

Answer 20

• natural antibiotic
• breaks bacterial cell walls
• saliva, tears

Question 21

what is an enzyme substrate

Answer 21

molecule that fits in binding site

Question 22

what is a lysozyme substrate

Answer 22

polysaccharide chains in bacterial cell wall
(when it breaks, the bacterial wall ruptures)