7. Respiration Questions And Answers

7. Respiration Questions

1. (a) Distinguish between gaseous exchange and respiration

 (b) Name the products of anaerobic respiration in plants

2. (a) State two phases of aerobic respiration

 (b) With a reason, state the phase that yields more energy

3. A process that occurs implants is represented by the equation below:-

C₆H₁₆O₆ 2C₂H₅OH + 2CO₂ + Energy

(Glucose) (Ethanol) (Carbon (IV) Oxide)

 (a) Name the process

 (b) State the economic importance of the process named in (a) above

4. Give a reason why it is difficult to calculate respiratory quotient (RQ) in plants

5. a) Explain what is meant by the term oxygen debt in human beings

 b) What are the end products of anaerobic respiration in animals

6. The apparatus below was set up by a student to find out the changes in gases during

germination

 a) After 48 hours the level of water in the U-tube at A and B was as shown. Explain the

observation

 b) Calculate the respiration quotient (RQ) from the equation below:-

2C₅₁H₉₈O₆+145O₂ 102 CO₂ + 98H₂O + Energy

 c) Identify the substrate being respired in the above equation

7. One molecule of lipid gives more energy than one molecule of glucose when respired aerobically

 but it is NOT always used as a respiratory substrate

 a) Give two reasons for this

 b) Name two disaccharides which are reducing sugar

8. (a) (i) Where in a cell does glycolysis take place?

(ii) Name the product of the above process

 (b) Briefly explain Kreb’s cycle in a plant cell during anaerobic respiration

9. How is the mammalian skin adapted to its protective function?

10. The oxidation state of a certain food is represented below by a chemical equation:-

 2 C₃H₂O₂N + 6O₂ (NH)₂CO₂ + 5CO₂ +5H₂O

 a) Calculate the respiratory quotients (RQ) of the food substrate

 b) Identify the food substrate

11. Whooping cough is a disease of the respiratory system name the causative agents and give two

 symptoms

12. How does the sunkness of stomata help in minimizing the rate of transpiration in plants

13. State two roles of adrenaline in man

14. Explain why a rat, though small eats more frequently than an elephant

15. Active yeast cells were added to dilute sugar solution in a container. The mixture was kept in a

 warm room. After a few hours bubbles of a gas were observed escaping from the mixture

 (a) Write an equation to represent the chemical reaction above

(b) State two economic importance of this type of chemical reaction in industry?

16. (a) Give two reasons why fats are not the main respiratory substrates in the body of a mammal

and yet they give a lot of energy when oxidized.

17. The equation below summarizes a metabolic process in plants.

 Glucose Ethanol + carbon (IV) oxide+ Energy

 State two industrial applications of the above equation.

18. (a) Differentiate between respiration and respiratory surface.

 (b) Why is an effective respiratory system often associated with a circulatory system.

19. State two reasons why lipids are rarely used as a respiratory substrate compound to

carbohydrates.

20. The equation below shows respiration for a certain food substrate. Study it and answer questions

 that follow:

2C₅₁H₉₈O₆ + 145O₂ 102CO₂ + 98H₂O

 (a) Calculate the respiratory Quotient, RQ

 (b) Suggest with reasons the possible food substrate

21. The apparatus below was used to investigate anaerobic respiration:-

(a) How would you remove dissolved oxygen from the glucose before the experiment

commencing?

 (b) State what happens to the lime water as the experiment proceeds to the end

(c) Describe the reactions in the experiment

 (d) Explain what would happen if the temperature of glucose solution and yeast was raised

beyond 45^oC?

7. Respiration Answers

1. (a) Gaseous exchange is the movement of gases across a respiratory surface; while

respiration is the biochemical breakdown of food molecules to produce energy (and carbon

IV oxide);

 (b) Ethanol/Alcohol;

Carbon (IV) oxide; and energy; (any two )

2. (a) Glycosis;

Krebs cycle;

(b) Krebs cycle; became oxygen is used to oxidize acid to water, Carbon (IV) Oxide and energy;

3. a) anaerobic respiration/fermentation;

 b) -baking of bread

-brewing industry

4. Carbon (IV) oxide produced in respiration is utilized in photosynthesis; oxygen produced

in photosynthesis is used in respiration;

5. a) Amount of oxygen required to get rid of lactic acid that accumulates in the body tissues when

oxygen available is lower than the demand

 b) Energy/A.T.P/ Lactic acid

6. (a) Germinating seeds respired using oxygen in the conical flask and produced CO₂, which was absorbed by the sodium hydroxide solution. A partial vacuum was created in the conical flask. The atmospheric pressure being higher pushes the water down to A and upto B.

(b) RQ – Vol of CO₂ produced = 102 = 0.70;

Vol. of O₂ used 145

(c) Lipids;

7. (a)

– Complete oxidation of lipids require a lot of oxygen;

– Lipids are insoluble in water hence difficult to transport in the body

– Complete oxidation of lipids take a longer time

(b) Maltose

Lactose

8. a) i) Cytoplasm

ii) Pyruvic acid

 b) Pyruvic acid is broken down; into ethanol and CO₂

9. a) RQ = CO₂ produced

O₂ consumed

= 5 ; = 0.83;

6

 b) Protein;

10. Bacteria, bacteria/ Symptoms

 – Prolonged coughing and vomiting

 – Convulsions and coma

 – Conjuctival haemorrhage

 – Severe bronchopneumonia

 Causative agents

 Symptoms

11. – Lowers saturation deficit by trapping H₂O moisture;

 – Protects direct sunlight to the stomatal pore;

12. They form depressions such that when wind blows it does not carry away water molecules.

13. – Increase rate of respiration

 – Speeds up the heart beat rate

14. A rat has a large surface area to volume ratio thus loses a lot of energy on form of heat therefore eats a lot to replace the lost energy;

15. a)Glucose water + carbon(iv) oxide + energy/210kj

Or

C₆H₁₂O₆ H₂O + CO₂ + ATP (energy) (mark as a whole) 1mk

16. Insoluble hence not easily transported to respiratory sites;

– They require more oxygen to be oxidized;

17. – Making of beer/Brewing/Ethanol/alcohol;

– Baking industry/Raising of the dough:

18. (a) Respiration – Chemical breakdown of food to release energy. 

Respiratory surface – Surface across which respiratory gases exchange.

 (b) Circulatory system transports the respiratory gases to and from tissues; hence maintains

steep concentration gradient around the respiratory surface;

19. – Not every soluble/not readily soluble therefore not easily transported to the site of respiration;

 – A lot of oxygen is required to oxidize one gram of fat/liquid than one gram of glucose;

20. a) RQ = Volume of CO₂ given out = 102 = 0.70;

Volume of O₂ used; 145

 b) Fats/ oil/ lipid;

 Reason: RQ for lipids/ fats/ oils is always less than 0.8; more oxygen is used than

carbon IV produced;

21. (a) Boiling

 (b) becomes milky/cloody /precipitate.

(c) Yeast produces enzyme amylase which catalyze breakdown of glucose anerosiccally into

energy (heat)

CO₂ and Ethanol

CO₂ makes lime water to become cloudy

 (d) High temperature donators enzymes, reduces/stops respiration/stops the reaction.