diffusion, osmosis, active transport 🤍 Flashcards
What is the definition of diffusion?
Diffusion is the movement of particles from an area of HIGHER concentration to an area of LOWER concentration.
Particles move to gain an equal concentration across the membrane (equilibrium).
How is the small intestine adapted for absorption by diffusion? (3 reasons)
- Has microvilli to increase surface area for absorption.
- Thin walls reducing diffusion distance.
- Capillaries and good blood supply
- Lacteals absorb products of lipid digestion.
What is the definition of osmosis?
Osmosis is the net movement of water from an area of high water potential to an area of lower water potential, across a partially permeable membrane.
What is the definition of active transport?
Active transport is the movement of particles against a concentration gradient from an area of low concentration to an area of higher concentration using energy (ATP) released in respiration and carrier proteins.
How does the concentration gradient affect the rate of diffusion?
Diffusion is faster if there is a steeper concentration gradient.
How does the surface area:volume ratio affect the rate of diffusion?
The higher the surface area:volume, the quicker the rate of diffusion.
How does the diffusion distance affect the rate of diffusion?
A shorter diffusion distance increases the rate of diffusion because the molecules have less distance to travel.
How does temperature affect the rate of diffusion?
The higher the temperature, the more kinetic energy the particles will have so they will move and mix more quickly.
