Enzymes and Digestion F4

Question 1

What are enzymes?

Answer 1

A biological catalyst that speeds up reactions without being used in the reaction itself

Question 2

What are enzymes made of?

Answer 2

Protein

Question 3

What is enzyme specificity?

Answer 3

Each enzyme is specific in that it will only work on one type of substrate

Question 4

What is the optimum of an enzyme?

Answer 4

When the enzyme is at its highest rate of activity

Question 5

How does low temperature affect enzyme activity?

Answer 5

Enzyme and substrates have low kinetic energy so there are fewer collisions and therefore enzyme activity is low

Question 6

How does high temperature affect enzyme activity?

Answer 6

At temperatures above the optimum enzymes begin to denature. The increase in temperature changes the shape of the active site, no longer fitting the substrate and so rate of activity decreases.

Question 7

How does pH affect enzyme activity?

Answer 7

On either side of the optimum pH they work less well because the incorrect pH changes the shape of the enzyme’s active site

Question 8

How does increasing enzyme concentration affect enzyme activity?

Answer 8

More active sites become available for substrates to fit into, increasing the activity

Question 9

How does higher enzyme concentration affect enzyme activity?

Answer 9

Rate of activity levels off as enzyme concentration increases because the number of substrate molecules becomes limiting and there are not enough to react with the extra enzymes

Question 10

What are inhibitors?

Answer 10

Molecules/Substances which fit loosely into an enzyme’s active site, stopping the substrate from fitting

Question 11

How do inhibitors affect enzyme activity?

Answer 11

These molecules reduce normal enzyme activity

Question 12

What is digestion?

Answer 12

Breaking down of large, insoluble food molecules into small, soluble molecules that can be absorbed

Question 13

What is absorption?

Answer 13

The process in which small, soluble food molecules are transferred from the gut to the blood system

Question 14

Substrate and product of CARBOHYDRASE

Answer 14

Starch => glucose

Question 15

Substrate and product of PROTEASE

Answer 15

Protein => amino acids

Question 16

Substrate and product of LIPASE

Answer 16

Fat => glycerol, fatty acids

Question 17

What are the functions of the lacteal?

Answer 17

Absorbs glycerol and fatty acids, returning them to the blood later

Question 18

What are the functions of the capillary network?

Answer 18

• absorbs amino acids and glucose

- provides excellent blood supply (maintains low concentration gradient)

Question 19

What are the functions of the thin and permeable surface lining?

Answer 19

• consists of single layer of epithelium cells creating short diffusion distance

Question 20

What does it mean to be thermostable?

Answer 20

Can work effectively at a wide range of temperatures.

Question 21

What does it mean to DESCRIBE a graph?

Answer 21

‘Say what you see’ - discuss trend of the graph using data

Question 22

What does it mean to EXPLAIN a graph?

Answer 22

‘Science bit’ - why it’s taking place

Question 23

How does increasing temperature affect enzyme activity?

Answer 23

It increases the kinetic energy, the number of collisions and therefore the rate of activity also increases

Question 24

What is the effect of pre-digesting food for babies?

Answer 24

It increase the surface area of the food, making it easier for enzymes to act on.

Question 25

What advantage does the shape of a villus provide?

Answer 25

Its finger-like shape increases the surface area