Enzymes

Question 1

enzymes are

Answer 1

biological catalysts

Question 2

advantages of enzymes as inorganic catalysts

Answer 2

specific to 1 catalytic reaction, don’t produce a range of unwanted byproducts, a lot faster

Question 3

extracellular enzymes

Answer 3

some enzymes are secreted from the cells where they’re made and act on their substrates extracellularly

Question 4

why are enzymes specific in their action

Answer 4

each have a specifically shaped active site that is complementary only to the shape of the substrate molecule

Question 5

why are enzymes described as biological catalysts

Answer 5

speed up reactions by up to 10^12 times at lower temperatures, neutral pH and normal pressures
able to function in conditions that sustain life
unchanged and reusable at end of reaction

Question 6

turnover number of an enzyme

Answer 6

the number of moles of substrate converted to product per mole of enzyme per second under conditions at which the concentration of all substrates is saturating

Question 7

why a non-functioning enzyme may cause serious disease

Answer 7

a metabolic disease due to genetic mutations which don’t allow the enzyme to catalyse chemical functions in the body to work normally

Question 8

activation energy

Answer 8

chemicals need energy to activate reaction in order to increase kinetic energy of the molecules so they move more and are likely to collide then reaction more successfully- enzymes lower this to speed up metabolic reactions

Question 9

Cofactor

Answer 9

Any substance that must be present to ensure enzyme-controlled reactions take place at the appropriate rate- non-protein

Question 10

Coenzymes

Answer 10

Small, organic, non-protein molecules

Question 11

Prosthetic groups

Answer 11

A cofactor permanently bound to an enzyme

Question 12

Enzyme inhibitor

Answer 12

Any substance or molecule that slows down the rate of an enzyme controlled reaction by affecting the molecule in some way

Question 13

Multi-enzyme complexes

Answer 13

Increase efficiency of metabolic reactions without increasing substrate concentration as they keep the enzyme and substrate molecules within the same vicinity and reduce diffusion time

Question 14

Why are many metabolic reactions carried out in particular regions or organelles

Answer 14

Increases efficiency of metabolism and some of the enzymes within organelles are bound into the organelle membrane

Question 15

Allosteric site

Answer 15

Region of an enzyme away from the active site where a non-competitive inhibitor may attach

Question 16

Inactivators

Answer 16

When permanent inhibitors denature the enzyme they are called

Question 17

Medical drugs that act by enzyme inhibition

Answer 17

Aspirin, ATPase inhibitors, ACE inhibitors, protease inhibitors, nucleoside reverse transcript inhibitors

Question 18

Active site

Answer 18

Indebted area on the surface of an enzyme molecule with a shape that is complementary to the shape of the substrate molecule

Question 19

Catalyst

Answer 19

Chemical that speeds up the rate of a reaction and remains unchanged and reusable at the end of a reaction

Question 20

Metabolic/metabolism

Answer 20

The chemical reactions that take place inside living cells or organisms

Question 21

Product

Answer 21

Molecule produced from substrate molecules by an enzyme-catalysed reaction

Question 22

Substrate

Answer 22

Molecule that is altered by an enzyme-catalysed reaction

Question 23

Enzyme-substrate complex

Answer 23

Complex formed by temporary binding of enzyme and substrate molecules during an enzyme-catalysed reaction

Question 24

Enzyme-product complex

Answer 24

Enzyme molecule with product molecules in its active site joined temporarily by non-covalent forces

Question 25

Q10

Answer 25

Temperature coefficient calculated by dividing the rate of reaction at (T+10)’C by the rate at T’C

Question 26

Concentration

Answer 26

Number of molecules per unit volume

Question 27

Competitive inhibition

Answer 27

Inhibition of an enzyme where the inhibitor molecule has a similar shape to the substrate and competes with it for the enzymes active site preventing formation of ES complexes

Question 28

Inhibitor

Answer 28

A substance that reduces or stops a reaction

Question 29

Non-competitive inhibition

Answer 29

Inhibition of an enzyme where the competitor molecule attached to a part of the enzyme but not the active site, if changes the shape of the active site which prevents ES complexes forming as it’s no longer complementary in shape

Question 30

3 ways inorganic ion cofactors increased the rate of enzyme-catalysed reactions

Answer 30

certain ions, co-substrates, changing charge distribution