PQ : 2.1 - 2.4 Exchange Of Substances Flashcards
Explain how the blood-gas barrier of the chicken is adapted to give more efficient gas
exchange than the blood-gas barrier of the dog.
(3)
Diffusion and active transport are mechanisms by which molecules can enter cells.
Compare and contrast these two mechanisms.
(3)
Endocytosis and exocytosis are processes that move large molecules into a cell or out of a
cell.
Compare and contrast the processes of endocytosis and exocytosis.
(3)
Explain why ATP is required for the movement of sodium ions into the cell. (2)
Describe how glucose molecules move into the cell. (2)
Describe how glucose moves into cells by facilitated diffusion. (2)
Explain how the structure of glycogen allows it to be an energy store. (3)
Give one function of the glycoproteins found in the cell surface membrane.
(1)
Explain how the structure of a phospholipid molecule contributes to the
partial permeability of a cell surface membrane. (3)
Assess the effect of this heart defect on the rate of oxygen diffusion between the alveoli
and the blood. (6)
All cells have a cell surface membrane.
Explain how phospholipids form a cell surface membrane. (3)
Explain why the phospholipids are arranged in two layers in a cell surface membrane. (3)
Describe the function of carrier proteins in a cell surface membrane. (4)
Determine why animal A does not need a circulation system but animal B does. (4)
Describe how glucose enters muscle cells through the cell membrane. (2)
Discuss the importance of ion transport across membranes in human health and disease.
Describe why single-celled organisms, such as Valonia ventricosa, do not need a
specialised gas exchange surface. (2)
