eww look you're all zyme

Question 1

what type of proteins are enzymes

Answer 1

globular

Question 2

what are catalysts

Answer 2

alter the rate of chemical reactions without undergoing permanent change themselves

Question 3

do the free energies of the products or reactants in a catalytic reaction have to be lower

Answer 3

products must be lowerrrrrr

Question 4

what does evry chem reaction require

Answer 4

AE

Question 5

do enzymes lower AE, what does this mean

Answer 5

yes, work at lower temps, metabolic processes work faster

Question 6

what is the active site of an enzyme made of?

Answer 6

relatively small number of AAs - it is a small depression within the much larger enzyme molecule

Question 7

where does a substrate fit into

Answer 7

enzyme-substrate complex

Question 9

how is the substrate and enzyme bonded together

Answer 9

temporarily between the AAs in the enzyme active site and the groups in the substrate molecule

Question 10

what does induced fit model suggest

Answer 10

that the active site of an enzyme forms as the substrate interacts and moulds around the substrate molecule

Question 11

how does the induced fit actually affect the enzyme

Answer 11

like a glove there is a general shape but it is able to put strain on substrate molecule to induce a catalytic reaction and change shape

Question 12

what is the general affect of temp on enzymes

Answer 12

temp increase KE of molecules and they will collide more frequently with enzymes’ active sites = more collisions = more enzyme-substrate complexes being formed and so the rate of reaction will increase but with a perpetual increase in temp the hydrogen bonds will begin to break and this will alter the shape of the active - at about 60 degrees it is so disrupted that is has denatured

Question 13

how does pH affect the active site

Answer 13

a change in pH alter the charge of the amino acids in the active site - as a result the substrate can no longer be attached to the active site and the so the enzyme substrate complex can no longer be formed

Question 14

what about a significant change in pH what would that do to an enzyme

Answer 14

it could cause the tertiary structures bonding to break - the active site would therefore be change and the es complex cannot be formed

Question 15

will a change in pH denature an enzyme

Answer 15

no probs only will reduce activity

Question 16

Define competitive inhibition

Answer 16

They have a similar shape to that of a substrate molecule

Question 17

Non competitive inhibitors, what are they

Answer 17

Do not bond to the active site as they have a different shape to the substrate so do not compete - bind to a site away from the active site known as the allosteric site - this causes the active the active site of the enzyme to change shape so it is no longer complimentary to the to the substrate - the es complex can no longer be formed.

Question 18

How will enzyme conc affect the rate of a catalytic reaction

Answer 18

Increasing enzyme conc increases the number of active sites available and for the substrate to collide with.
More ES complexes can form as enzyme conc increases

Question 19

what is a fibrous protein

Answer 19

they form long chains which run parallel to one another. these chains are linked by cross bridges and so form very stable molecules - one example is collagen

Question 20

what is the structure of collagen

Answer 20

its primary structure is an unbranched polypeptide chain
- the secondary structure is a polypeptide that is very tightly wound
- lots of amino acid and glycine helps with close packing
- in the tertiary the chain is twisted into a second helix.

• quaternary is made up of three such polypeptides chains wound together like a rope