enzymes

Question 1

what is a catalyst

Answer 1

a substance that speeds up a chemical reaction and is not changed by the reaction

Question 2

what are enzymes

Answer 2

proteins that function as biological catalysts

Question 3

functions of enzymes

Answer 3

Enzymes lowers amount of energy needed for reaction to take place

Enzyme lowers the activation energy needed for reaction to take place

Question 4

what is the substrate

Answer 4

the molecule(s) before they are made to react

Question 5

what is the product

Answer 5

the molecule(s) that are made in a reaction

Question 6

what is a catabolic reaction

Answer 6

molecules are broken down

Question 7

what is an anabolic reaction

Answer 7

molecules are combined

Question 8

what is an optimum temperature

Answer 8

Enzymes have an optimum temperature: the temperature at which they work best giving the fastest reaction ≈ 37°C in animals
When temperature increases, molecules move faster so collide with an enzyme in less time

Having more energy makes them more likely to bind to active site.

Question 9

what happens if the temperature of the enzyme is too high

Answer 9

If temperature is too high, enzyme molecules vibrate too vigorously and enzyme is denatured; it loses its shape and will no longer bind with a substrate.

Question 10

what happens if the temperature of the enzymes is too low

Answer 10

When the temperature is too low there is not enough kinetic energy for the reaction so it reacts too slowly.

Question 11

effect of pH on enzymes

Answer 11

Enzymes are sensitive to pH

Some enzymes work best in an acid and others in an alkaline

Enzymes work best at their optimum pH

If the pH is changed then the enzyme will denature and will no longer fit with substrate- no reaction takes place

Question 12

uses for enzymes

Answer 12

• seeds to germinate
• biological washing powders
• food industry

Question 13

use of enzymes for seeds to germinate

Answer 13

the enzymes turn insoluble food stores to soluble

Question 14

use of enzymes for biological washing powder

Answer 14

enzymes are added to washing powders to help remove stains for example:

Lipase for lipids from fatty foods and greasy fingerprints

Protease for proteins from blood stains

Question 15

use of enzymes for food industry

Answer 15

Isomerase converts glucose to fructose which is sweeter, so less is needed to give a sweet taste

Pectinase helps break down cell walls in fruit juice production so it increases yield, lowers viscosity and reduces cloudiness