KO 1: Section 5: Transport Across Membranes Flashcards
1
Q
Definition of Diffusion
A
Spreading out of the particles (gas/ solution) resulting in a net movement from an area of higher concentration to an area of lower concentration.
Passive transport
2
Q
Definition of Osmosis
A
The diffusion of water from a dilute solution to a concentrated solution through a partially permeable membrane.
Passive transport
3
Q
Definition of Active transport
A
The movement of substances from a more dilute solution to a more concentrated solution (against a concentration gradient). Requires energy from respiration.
4
Q
Uses of Diffusion
A
- Oxygen and carbon dioxide in gas exchange (leaves and alveoli).
- Urea from cells into the blood plasma for excretion in the kidney.
5
Q
Uses of Osmosis
A
- Movement of water into and out of cells.
6
Q
Uses of Active Transport
A
- Absorption of mineral ions (low concentration) from soil into plant roots.
- Absorption of sugar molecules from lower concentrations in the gut into the blood which has a higher sugar concentration.
7
Q
Factors Affecting Diffusion
A
- Difference in concentrations (concentration gradient).
- Temperature.
- Surface area of membrane.
8
Q
Adaptations of Exchange Surfaces
A
