Chemistry 9th Chap 8 : Topic 10 - Maryam Publications

Chemistry Chapter 8 : Topic 10

Respiration and Energy Storage

1 / 20

During intense physical exercise, muscle cells may switch from aerobic respiration to anaerobic respiration. Which statement best explains this change?

A) Oxygen supply becomes insufficient, so cells partially break down glucose without oxygen

B) Oxygen supply increases, so cells prefer anaerobic respiration

C) Carbon dioxide is required for anaerobic respiration to occur

D) ATP production completely stops in muscles

2 / 20

Which statement correctly compares aerobic and anaerobic respiration in terms of energy output?

A) Aerobic respiration produces significantly more energy than anaerobic respiration

B) Both produce equal amounts of energy per glucose molecule

C) Neither process produces usable energy

D) Anaerobic respiration produces more energy than aerobic respiration

3 / 20

Why is respiration considered an exothermic process?

A) It requires sunlight to proceed

B) It releases energy during breakdown of glucose

C) It absorbs heat from the surroundings

D) It stores energy in glucose molecules

4 / 20

Which best describes the role of ATP in biological systems?

A) It is the immediate energy carrier for cellular processes

B) It acts as a long-term energy storage molecule

C) It prevents anaerobic respiration

D) It stores genetic information

5 / 20

During anaerobic respiration in human muscles, which substance is produced?

A) Oxygen

B) Lactic acid

C) Glucose

D) Ethanol

6 / 20

Which organism commonly produces ethanol during anaerobic respiration?

A) Yeast

B) Humans

C) Plants

D) Fishes

7 / 20

Why does aerobic respiration release more energy than anaerobic respiration?

A) Because glucose is completely oxidized into carbon dioxide and water.

B) Because no oxygen is used.

C) Because it produces lactic acid.

D) Because glucose is partially broken down.

8 / 20

Which statement best explains why lipids are considered good energy reserves?

A) They dissolve easily in blood plasma.

B) They are immediately used in all cellular reactions.

C) They contain more energy per gram than carbohydrates.

D) They store less energy than carbohydrates.

9 / 20

What is the main advantage of storing energy as lipids instead of glucose?

A) Lipids dissolve easily in water.

B) Lipids produce energy without respiration.

C) Lipids store energy in a more compact and efficient form.

D) Lipids are heavier than glucose.

10 / 20

Which condition is most likely to trigger anaerobic respiration in humans?

A) Resting state with normal oxygen supply

B) Digestion of food in stomach

C) Vigorous exercise causing oxygen shortage

D) High oxygen availability during sleep

11 / 20

Which statement correctly describes energy release during respiration?

A) Energy is absorbed and stored in glucose.

B) Energy is released gradually in usable form ATP.

C) Energy is only released as light.

D) Energy is destroyed during the process.

12 / 20

Why does anaerobic respiration lead to fatigue in muscles?

A) Because ATP production increases too much.

B) Because oxygen increases excessively.

C) Due to accumulation of lactic acid.

D) Because glucose is fully oxidized.

13 / 20

Which equation best represents aerobic respiration?

A) Glucose → Lactic acid + Energy

B) Glucose + Oxygen → Carbon dioxide + Water + Energy

C) Carbon dioxide + Water → Glucose + Oxygen

D) Glucose → Ethanol + Carbon dioxide

14 / 20

Why is respiration essential for all living organisms?

A) It prevents digestion.

B) It stores food permanently.

C) It produces oxygen.

D) It provides energy required for life processes.

15 / 20

Which of the following is NOT a characteristic of lipids?

A) Immediate energy source like ATP.

B) High energy content

C) Insoluble in water

D) Long-term energy storage

16 / 20

What is the primary difference between respiration and combustion?

A) Combustion releases energy in a controlled manner.

B) Respiration is a controlled release of energy in cells.

C) Respiration occurs only outside living cells.

D) Both are non-energy releasing processes.

17 / 20

During starvation, the body mainly uses stored lipids for energy because:

A) Lipids provide high energy yield when carbohydrates are low.

B) Lipids replace ATP directly.

C) Lipids are quickly converted into oxygen.

D) Lipids stop respiration completely.

18 / 20

Which process directly produces ATP in cells?

A) Digestion of food in stomach

B) Photosynthesis only

C) Respiration

D) Excretion

19 / 20

Why is anaerobic respiration considered less efficient?

A) It breaks glucose completely.

B) It requires sunlight.

C) It releases much less ATP per glucose molecule.

D) It produces no energy.

20 / 20

Which statement best explains energy storage in lipids?

A) Lipids are converted into ATP directly in blood plasma.

B) Lipids are stored in adipose tissue for long-term energy supply.

C) Lipids are used only in respiration of plants.

D) Lipids are stored in blood for immediate use.

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