Diffusion, Osmosis and Active Transport Flashcards
What is diffusion?
Diffusion is the movement of particles from an area of high concentration to an area of low concentration.
What is osmosis?
Osmosis is the movement of water molecules across a selectively permeable membrane from an area of low solute concentration to an area of high solute concentration.
True or False: Diffusion requires energy input.
False. Diffusion is a passive process and does not require energy input.
What is active transport?
Active transport is the movement of particles across a cell membrane against the concentration gradient, requiring energy input in the form of ATP.
Fill in the blank: Osmosis is the movement of ________ molecules across a selectively permeable membrane.
water
Which type of transport requires energy input: diffusion, osmosis, or active transport?
Active transport
What is the main driving force behind diffusion?
The main driving force behind diffusion is the concentration gradient.
True or False: Osmosis can occur in both plant and animal cells.
True
In which direction do molecules move in diffusion?
Molecules move from high concentration to low concentration in diffusion.
What is the role of carrier proteins in active transport?
Transport proteins allow the movement of particles across the cell membrane in active transport.
Fill in the blank: In active transport, particles move ________ the concentration gradient.
Up
True or False: Osmosis is a form of passive transport.
True
Which type of transport is responsible for the uptake of nutrients in cells?
Active transport
Fill in the blank: Active transport requires ________ input to move particles across the cell membrane.
energy
True or False: Active transport is the movement of particles up the concentration gradient.
True
What is the role of ATP in active transport?
ATP provides the energy needed for active transport to move particles against the concentration gradient.
What factors affect diffusion
- Diffusion distance (determined cell size and layers)
- concentration gradient
- surface area (allows more space for diffusion)
- temperature
How does diffusion distance affect the rate of diffusion?
Smaller diffusion distance means diffusion occurs faster and larger diffusion distance means it occurs slower
How does concentration gradient affect the rate of diffusion
A steeper concentration gradient means the rate of diffusion will increase and a lower concentration gradient will decrease the rate of diffusion
How does surface area affect the rate of diffusion?
More surface area means the particles have more space to move to so diffusion happens faster
How does temperature affect the rate of diffusion?
Higher temperature increases the kinetic energy of the particles, increasing the rate of diffusion
What happens during osmosis in plant cells
In a solution with high water potential, water moves into the cell, making it turgid/firm (turgor pressure)
In a solution with low water potential, water moves out of the cells, reducing turgor pressure causing the cell content to collapse, becoming plasmolysed
What happens to animal cells during osmosis
In a solution with high water potential, water moves into the cell causing it to swell and potentially burst. This is called lysis
In a solution with low water potential, water moves out of the cells causing the cell to shrink and become crenated.
