2.1.4 - enzymes💯

Question 1

enzymes

Answer 1

proteins that act as biological catalysts, without the need of harsh conditions

Question 2

anabolic reactions

Answer 2

synthesis of larger molecules from smaller ones
chemical reactions required for growth

Question 3

catabolic reactions

Answer 3

break down large chemicals and release energy

Question 4

metabolism

Answer 4

all of the chemical reactions that take place within an organism

Question 5

vmax

Answer 5

maximum initial velocity of an enzyme catalysed reaction

Question 6

activation energy

Answer 6

the minimum amount of energy required to start a chemical reaction

Question 7

enzymes and activation energy

Answer 7

enzymes lowe the activation energy

Question 8

enzymes and collisions

Answer 8

enzymes increase the rate of successful collisions and overall rate of reaction

Question 9

active site

Answer 9

part of enzyme where the chemical reaction happens

Question 10

lock and key theory

Answer 10

enzymes active site (lock) us already in appropriate conformation for the substrate to bind. the substrate easily fits into the active site, and no alteration is needed

Question 11

enzyme substrate complex

Answer 11

when the substrate collides with the active site

Question 12

enzyme product complex

Answer 12

when the substrate reacts and the products are formed

Question 13

induced fit hypothesis

Answer 13

theory that states that after partial binding of the substrate to an enzyme, alters the structure of the enzyme so that the active site becomes complementary.

Question 14

intracellular enzymes

Answer 14

enzymes that function within cells

Question 15

example of intracellular enzymes

Answer 15

catalase - catalyses the breakdown of hydrogen peroxide into water and oxygen

Question 16

extracellular enzymes

Answer 16

enzymes that are synthesised and secreted to work outside the cell

Question 17

example of extracellular enzymes

Answer 17

single celled organisms rely on these to make use of polymers for nutrition
bacteria and yeast release enzyjmes to break down large molecules lile proteins
digestion - amylase and trypsin.

Question 18

digestion of starch

Answer 18

1. starch polymers are partially broken down into maltose, where amylase is produced.
2. maltose is broken down into glucose where maltase is present

Question 19

digestion of proteins

Answer 19

trypsin - catalyses the digestion of proteins into smaller peptides, which can then be broken down further. found in the pancreas.

Question 20

factors that affect enzyme activity

Answer 20

pH, temp, concentration of enzyme or substrate

Question 21

effect of temperature on enzyme activity

Answer 21

increasing temp of a reaction environment increases kinetic energy of the particles, leading to more successful collisions, so more ESCs made, increasing rate of reaction

Question 22

temperature coefficient

Answer 22

measure of how much the rate of reaction increases with a 10C rise in temperature - normally taken as 2

Question 23

denatured

Answer 23

loss of an enzymes normal shape so that it no longer functions as the bonds break due to vibrations. happens in the wrong conditions

Question 24

optimum temperature for ennzymes

Answer 24

temp where the enzyme has the highest rate of activity
- human - 37C
- thermophillic bacteria 70C
- psychrophilic organisms 5C

Question 25

pH and hydrogen ion concentration

Answer 25

a change in pH refers to a change in hydrogen ion concentration more H ions - low pH less H ions - high pH

Question 26

renaturation

Answer 26

regaining the correct tertiary structure after dentauration of the protein

Question 27

effect of H ions on R groups

Answer 27

more H ions present, the less R groups will be able to interact with eachother

Question 28

effect of increasing substrate concentration

Answer 28

increasing the number of substrate particles means a higher collision rate with the active site of enzymes and the formation of more enzyme substrate compleces - so the rate increases

Question 29

only way to increase rate of reaction at Vmax of substrate concentration

Answer 29

add more enzymes

Question 30

effect of increasing enzyme concentration

Answer 30

increasing the number of available active sites in a particular area or volume, leading to more ESCs

Question 31

inhibitor

Answer 31

molcules that prevent enzymes from carrying out their normal function of catalysis

Question 32

two types of enzyme inhibition

Answer 32

competitive and non competitive

Question 33

how competitive inhibitors work

Answer 33

- molecule that has a similar shape to the substrate of an enzyme can fit into the active site of the enzyme - blocks substrate from active site, preventing the enzyme from catalysing the reaction - enzyme cannot carry out iys function

Question 34

reversible inhibitors

Answer 34

bind temporarily to the active site of the enzyme

Question 35

competitive inhibitors effect rate on reaction

Answer 35

reduce the rate of reaction but does not chage the Vmax - if enough substration concentration then there will be more substrates than the inhibitors, reaching the Vmax

Question 36

examples of competitive inhibitors

Answer 36

statins - stop cholesterol from being produced aspirin - prevents the synthesis of prostaglandins

Question 37

non competitive inhibitor

Answer 37

- inhibitor binds to the allosteric site, not the active site - causes the tertiary strucure to change, meaning the substrate is no longer complementary - enzyme cannot carry out function

Question 38

effect of a non competitive inhibitor

Answer 38

reduces the rate of reaction - adding more substrate will not overcome the effect.

Question 39

examples of non competitive inhibitors

Answer 39

organophosphates and proton pump inhibitors

Question 40

end product inhibition

Answer 40

the product of a reaction inhibits the enzyme required for the reaction

Question 41

examples of end product inhibition

Answer 41

glucose -- (phosphofructokinase) --> ATP - when ATP levels are too high more ATP binds to the allosteric site on PFK, preventing the productuon of more ATP

Question 42

cofactor

Answer 42

non protein enzyme helpers

Question 43

how cofactors are obrained

Answer 43

via diet as minerals - iron calcium chloride and zinc ions

Question 44

example of cofactor

Answer 44

amylase contains an inorganic cofactor (cl ion) which enables formation of the active site for the substrate starch

Question 45

coenzyme

Answer 45

organic co factor

Question 46

prosthetic group

Answer 46

cofactor that binds tightly to an enzyme and forms a permanent feature of that protei.

Question 47

example of a prosthetic group

Answer 47

Zn2+ for carbonic anhydrase

Question 48

precursor activation

Answer 48

inactive form of the enzyme due to the fact that they can cause damage to the body when active. undergo a change un shape to the active site to be activated

Question 49

apoenzyme

Answer 49

before the cofactor is added

Question 50

holoenzyme

Answer 50

apoenzyme + holoenzyme

Question 51

example of precursor activation

Answer 51

inactive pepsinogen released into the stomach to digest proteins activated by food acid pH then transforms into enzyme pepsin