1.4 proteins

Question 1

how many different amino acids are there

Answer 1

20

Question 2

where are amino acids made

Answer 2

made in the Golgi and then modified into glycoproteins

Question 3

what three things does and amino acid have

Answer 3

1. amino group
2. carboxyl group
3. R group (which is the thing that changes for each amino acid)

Question 4

what bond bonds the amino and carboxyl group together

Answer 4

peptide bond

Question 5

what are the 4 structures of a protein

Answer 5

primary
secondary
tertiary
quaternary

Question 6

what is the primary structure

Answer 6

the sequence of amino acids

Question 7

what are the two types of secondary structure

Answer 7

alpha helix
beta pleated sheet

Question 8

what are the tree bonds that bond the tertiary structure

Answer 8

ionic
hydrogen
disulphide

Question 9

what is the structure of a tertiary protein

Answer 9

3D
globular
fibrous

Question 10

what is the quaternary structure

Answer 10

several polypeptide chains joined together sometimes with a non-protein molecule

Question 11

what does an enzyme do

Answer 11

lowers the activation energy needed to start a reaction

Question 12

describe the steps of the induced fit model

Answer 12

1. the substrate gets close in proximity with the enzyme
2. the active site changes shape slightly so it is complementary to the substrate
3. this forms an E-S (enzyme-substrate) complex
4. the enzyme then returns to its original shape to push out the two product molecules and is free to bind to another substrate

Question 13

what are the 4 factors affecting enzymes activity

Answer 13

Temperature
pH
Enzyme concentration
Substrate concentration

Question 14

how does temperature affect the enzymes activity

Answer 14

more temp = more kinetic energy leading to more successful collision
however if the temperature gets too high tertiary bonds are broken and the enzymes active site will denature so less E-S complexes as less successful collisions

Question 15

how does pH affect the enzymes activity

Answer 15

rises with pH until reaches optimum and then decreases activity as enzymes denature at both too acidic and too alkali circumstances

Question 16

how does enzyme concentration affect enzyme activity

Answer 16

the greater the amount of enzyme concentration the more likely there will be successful collisions
the rate will plateau when all active sites are full.

Question 17

how does substrate concentration affect enzyme activity

Answer 17

as the reaction proceeds more and more enzymes active sites are filled until all the substrate molecules occupy the active sites
this is called saturation of the active sites

Question 18

name the two types of inhibitors

Answer 18

competitive and non-competitive

Question 19

describe how a competitive inhibitor works

Answer 19

a competitive inhibitor bonds to the active site of the enzyme preventing the substrate from bonding therefore stopping an E-S complex

Question 20

describe how a non-competitive inhibitor works

Answer 20

the inhibitor binds to the enzyme (not at the active site) which then causes a conformational change to the active site making the enzyme and substrate no longer complementary to each other