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. p
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.