Gas Exchange & Transport

Question 1

Explain the relationship between the structural features (large surface area, moist, one or two cells thick and surrounded by an extensive capillary system) and function of gaseous exchange surfaces

Answer 1

The walls of the alveoli share a membrane with the capillaries. This lets oxygen and carbon dioxide diffuse and the moist surroundings aid the absorption process, the greater the surface area, the more gas exchange can occur.

Question 2

Explain how the structure and function of capillaries facilitates the exchange of materials

Answer 2

The capillary wall is made of a single layer of cells to minimize the diffusion distance and aid the process for permeable materials.

Question 3

Characteristics of absorptive surfaces within the digestive system (Villi)

Answer 3

Villi are specialized for absorption in the small intestine as they have a thin wall, one cell thick, which enables a shorter diffusion path. They have a large surface area so there will be more efficient absorption of fatty acids and glycerol into the blood stream

Question 4

Describe the role of digestive enzymes (A,P,L)

Answer 4

Enzymes that break down large complex molecules into smaller simple molecules
Amylase- Carbohydrates - sugars
Protease- proteins - amino acids
Lipase - fatty acids- glycerol

Question 5

Different types of nitrogenous wastes are produced by the breakdown of proteins (A,U,UA,C)

Answer 5

Ammonia, urea, uric acid, and creatinine