Chapter 9: Respiration

Question 1

Define aerobic respiration

Answer 1

an exothermic reaction in which glucose is broken down using oxygen to produce carbon dioxide and water and release energy for the cells

Question 2

What is an exothermic reaction?

Answer 2

transfers energy to the environment

Question 3

Why do living cells need energy?

Answer 3

• to build up large molecules from smaller ones to make new cell material
• breaking down larger molecules into smaller, soluble ones (during digestion)

Question 4

Why do animals need energy?

Answer 4

-to make muscles contract: all muscular activities require energy

Question 5

What is muscle tissue made up of?

Answer 5

• protein fibres which contract when energy is transferred from respiration
• contain many mitochondria to carry out aerobic respiration

Question 6

What is glycogen?

Answer 6

a carbohydrate store in animals

Question 7

What happens when:

• your heart rate increases
• arteries supplying blood to your muscles dilate

Answer 7

• these changes increase the flow of oxygenated blood to your exercising muscles.
• this increases the the rate of supply of oxygen and glucose for the increases cellular respiration rate needed
• it also increases the rate that carbon dioxide is removed from your muscles.

Question 8

What happens when your breathing rate increases?

Answer 8

-the rate of which oxygen is brought into your body and picked up by your red blood cells is increased, and this oxygen in carried to your muscles.

Question 9

What happens when glycogen stored in the muscles is converted back to glucose?

Answer 9

-cells are supplied with the fuel they need to increase cellular respiration

Question 10

Name 3 body responses to exercise

Answer 10

• increase in heart rate and breathing rate
• glycogen stores in the muscles are converted back to glucose
• flow of oxygenated blood to the muscles increase

Question 11

define anaerobic respiration

Answer 11

an exothermic reaction in which glucose is broken down in the absence of oxygen to produce lactic acid in animals, and ethanol and carbon dioxide in plants.

Question 12

Why is anaerobic respiration not as efficient as aerobic respiration

Answer 12

glucose molecules are not broken down completely, and so less energy is being transferred.

Question 13

What is the end product if anaerobic respiration?

Answer 13

lactic acid; which builds up in the muscles

Question 14

What is the oxygen debt?

Answer 14

The extra oxygen that must be taken into the body after exercise has stopped to complete the aerobic respiration of lactic acid.

Question 15

What is the word equation for oxygen debt repayment?

Answer 15

lactic acid + oxygen ——> carbon dioxide + water

Question 16

What is metabolism?

Answer 16

The sum of all reactions in your body

Question 17

Name 2 common metabolic reactions

Answer 17

• conversions of glucose to starch, glycogen, and cellulose

- use of glucose and nitrate ions to form amino acids that are then used to make proteins

Question 18

Name 2 metabolic functions of the liver

Answer 18

• detoxifying poisonous substances such as ethanol
• breaking down old, worn out blood cells and storing the iron until it is needed
• dealing with lactic acid produced in the muscles

Question 19

How does the liver remove lactic acid?

Answer 19

-liver converts lactic acid back to glucose, which is then broken down to carbon dioxide and water.