Fnm 002 Enzymes And Catalysis

Front 1

In addition to reactive groups from amino acid side chains, enzymes may contain non-protein molecules. Give two examples.

Back 1

A prosthetic group, and a coenzyme.

Front 2

Coenzymes are small organic molecules that can be loosely or tightly bound to an enzyme. Tightly bound coenzymes can be called...

Back 2

Allosteric groups

Front 3

What is an 'allosteric group'?

Back 3

Coenzymes are small organic molecules that can be loosely or tightly bound to an enzyme. Tightly bound coenzymes can be called allosteric groups.

Front 4

What is a prosthetic group? (wrt enzymes)

Back 4

A *covalently* bonded organic compound or chelated (Forms a compound containing a ligand bonded to a central metal atom at two or more points with) metal ion

Front 5

What does 'chelated' mean?

Back 5

Form a chelate with

--> A compound containing a ligand (typically organic) bonded to a central metal atom at two or more points

Front 6

'A *covalently* bonded organic compound or chelated (Forms a compound containing a ligand bonded to a central metal atom at two or more points with) metal ion'

Back 6

A prosthetic group

Front 7

Prosthetic groups are covalently bonded to enzymes T/F

Back 7

T (coenzymes are not)

Front 8

'Tightly, but *not* covalently, bound organic compound that can be removed from an enzyme (e.g. by dialysis)'.

Back 8

Coenzyme

Front 9

What is a coenzyme?

Back 9

Tightly, but *not* covalently, bound organic compound that can be removed from an enzyme (e.g. by dialysis).

Front 10

Coeznymes are covalently bonded to enzymes T/F

Back 10

F (prosthetic groups are)

Front 11

Coenzymes can be removed from enzymes T/F If so, how?

Back 11

T --> Dialysis

Front 12

What is dialysis?

Back 12

The separation of particles in a liquid on the basis of differences in their ability to pass through a membrane

Front 13

'The separation of particles in a liquid on the basis of differences in their ability to pass through a membrane'

Back 13

Dialysis

Front 14

Enzyme + prosthetic group/coenzyme =

Back 14

Holo-enzyme (catalytically active)

Front 15

What is a holo-enzyme (wrt 'equation')?

Back 15

Enzyme + prosthetic group (a holo-enzyme is catalytically active)

Front 16

A holo-enzyme is catalytically inactive T/F

Back 16

F (An apo-enzyme is catalytically inactive)

Front 17

A holo-enzyme is catalyticall active T/F

Back 17

T


2120160211 - On train, just left Marylebone after formative mocks

Front 18

'An enzyme without a prosthetic group or coenzyme'

Back 18

An apo-enzyme (catalytically inactive)

Front 19

What is an 'apo-enzyme'?

Back 19

An enzyme without a prosthetic group or coenzyme. It is catalytically inactive.

Front 20

The active site of an enzyme can be considered to consist of:

Back 20

A binding site and a catalytic site

Front 21

Which part of the active site of an enzyme is being described?

'Non-covalent interactions between amino acid side-chains and the substrate(s)'

Back 21

The binding site

Front 22

You need to learn the acidic/basic/hydrophilic/aromatic etc. amino acids.

Back 22

They are in the lecture notes

Front 23

Does multiple interactions with the active site lead to a high, or low degree of specificity for the substrate(s) bound?

Back 23

High

Front 24

Enzymes can/cannot distinguish between D- and L-isomers and between cis- and trans-isomers

Back 24

Can

Front 25

Cis/Trans?

Back 25

Cis

Front 26

Cis/trans?

Back 26

Trans

Front 27

Reactive groups on the surface of the enzyme catalyse the reaction by:

Donating or withdrawing electrons T/F

Back 27

T

Front 28

Reactive groups on the surface of the enzyme catalyse the reaction by:

Stabilising or generating free radical intermediates T/F

Back 28

T

Front 29

Reactive groups on the surface of the enzyme catalyse the reaction by:

Forming temporary covalent bonds T/F

Back 29

T

Front 30

Enzymes act by increasing the activateion energy of the reaction T/F

Back 30

F, they lower the activation energy

Front 31

Enzymes act by increasing the speed at which equilibrium is achieved T/F

Back 31

T

Front 32

Enzymes act by altering the position of the equilibrium T/F

Back 32

F

Front 33

What are the six groups of enzymes?

Back 33

Oxidorenductases

Transferases

Hydrolases

Lyases

Isomerases

Ligases (synthetases)

Front 34

Need to learn about enzyme classification

Back 34

In lecture notes - systematic number (EC number)

e.g. EC 4.1.1.28 (understand this)

Front 35

Hydrolysis of esters of basic amino acids

Back 35

Trypsin

Front 36

Hydrolysis of esters of aromatic amino acids

Back 36

Chymotrypsin

Front 37

Hydrolysis of esters of small neutral amino acids

Back 37

Elastase

Front 38

What is the change to the primary AA sequence to cause the varient form of methylene tetrahydrofolate reductase (MTHFR)

Back 38

Alanine 226 mutated to valine (leads to abnormal metabolism of folic acid, can be overcome with high intakes of folate)

Same gene is associated with spina bifida and other neural tube defects

Front 39

What is V(max)?

Back 39

The maximum rate of reaction of the enzyme when the enzyme is saturated with substrate

Front 40

The maximum rate of reaction of the enzyme when the enzyme is saturated with substrate

Back 40

V(max)

Front 41

What is K(m)?

Back 41

The inverse measure of the affinity of the enzyme for its substrate - it is the concentration of the substrate required to achieve half (V)max

Front 42

The inverse measure of the affinity of the enzyme for its substrate - it is the concentration of the substrate required to achieve half (V)max

Back 42

K(m)

Front 43

What are the units of V(max)?

Back 43

mol of product formed/unit time

Front 44

What are the units of K(m)

Back 44

mol/L (concentration)

Front 45

Back 45

Important to understand!