Theory question 102
HomeostasisAn individual ate a hot and large meal of cassava with salty groundnut soup. The individual was sweating profusely and did not drink water after the meal.
(a) State one role each played by the following organs involved in the activity above: (i) mouth; (ii) skin; (iii) tongue; (iv) kidney; (v) stomach; (vi) small intestine; (vii) large intestine; (viii) liver.
(b) Name three of the organs listed in 2(a) that contain enzymes needed to breakdown the food.
(c) Name three digestive enzymes that would be involved in the digestion of the meal.
(d) Name two end products of the meal after digestion.
(e)(i) State one effect that the excess salt in the meal might have on the individual. (ii) State three advantages that the individual would derive from the meal.
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(a)(i) Mouth: teeth chew the food; saliva (ptyalin) begins starch digestion.
(ii) Skin: sweat glands remove water and salt and cool the body.
(iii) Tongue: tastes the food and rolls it into a bolus for swallowing.
(iv) Kidney: removes excess salt and conserves water (osmoregulation), producing concentrated urine.
(v) Stomach: stores and churns food; pepsin starts protein digestion; acid kills germs.
(vi) Small intestine: completes digestion of starch, proteins and fats and absorbs the products through the villi.
(vii) Large intestine: absorbs water from undigested food and forms faeces.
(viii) Liver: makes bile to emulsify fats; stores excess glucose as glycogen; deaminates excess amino acids.
(b) Mouth, stomach, small intestine (also accept pancreas/duodenum if listed).
(c) Any three: salivary amylase (ptyalin); pancreatic amylase; maltase; pepsin; trypsin; erepsin (peptidase); lipase.
(d) Any two: glucose; amino acids; fatty acids and glycerol.
(e)(i) Any one: raised blood pressure; thirst and dehydration; strain on the kidneys; water retention/swelling.
(ii) Any three: energy from the cassava (carbohydrate); protein from groundnut for growth and repair; oil (fat) from the soup for energy and warmth; minerals and vitamins.
Link each organ's role to this salty, starchy meal and the lack of drinking water.