Biology 2b

Question 1

What are enzymes?

Answer 1

Biological catalysts.

Question 2

What is a catalyst?

Answer 2

A substance that increases the rate of reaction by providing an alternative route. It is not used up or changed in the reaction.

Question 3

What is unique about every enzymes?

Answer 3

They have a particular shape to fit a certain substrate.

Question 4

What two things need to be kept optimum for enzymes to work?

Answer 4

pH and temperature.

Question 5

What happens to enzymes if they are not at their optimum?

Answer 5

They become denatured, change shape and no longer work properly because they don’t fit the complementary substrate.

Question 6

Which enzyme is used to digest fats and what are the products?

Answer 6

Lipase

Fatty acids and glycerol.

Question 7

What is the role of bile an where is it produced

Answer 7

Emulsifies fats ready for digestion
Made in the liver
Stored in the gallbladder.

Question 8

Which organs produce lipase, carbohydrase and protease enzymes?

Answer 8

The pancreas and the small intestine.

Question 9

What is respiration?

Give the word equation.

Answer 9

Releasing energy from glucose.

Glucose + Oxygen = Carbon dioxide + Water

Question 10

What do animals use energy for?

Answer 10

Building molecules
To allow muscles to contract
Regulation of body temperature.

Question 11

What structure is adopted by DNA?

Answer 11

Double helix

Question 12

What is the type of cell division that produces gametes?

Answer 12

Meiosis

Question 13

What is a stem cell?

Where can we get them?

Answer 13

A cell that is still undifferentiated.

We get them from embryos

Question 14

What is glycogen?

Answer 14

The glucose that is stored in muscles and the liver.

Question 15

What is anaerobic respiration?

Answer 15

Respiration without oxygen.

Glucose = Energy + Lactic acid.

Question 16

How is isomerase used in slimming foods?

Answer 16

It converts glucose syrup into fructose syrup which is sweeter so less of it is used, so less calories are consumed.

Question 17

What chromosomes do males have?

Answer 17

XY

Question 18

What is a recessive gene?

Answer 18

You need 2 to inherit the phenotype (characteristic).

Question 19

What is an allele?

Answer 19

A different form of a gene.

Question 20

Who was Mendel?

Answer 20

A monk that experimented with inheritance in pea plants.

Question 21

Why was it hard for Mendel to get his opinion across?

Answer 21

• It was hard for him to get his work published

- There was little knowledge of inheritance.

Question 22

Is cystic fibrosis recessive or dominant?

Answer 22

Recessive.

Question 23

What 3 ways are fossils made?

Answer 23

• Replacement by minerals.
• Casts and impressions
• Preservation in places where there is no decay.

Question 24

What are problems with the fossil layer?

Answer 24

Soft bodied organisms don’t fossilise.

Not everywhere has been excavated.

Question 25

When do species become extinct?

Answer 25

When they can’t evolve fast enough.