B2.1 - Supplying The Cell Flashcards
What is diffusion?
The net movement of particles from a higher concentration to a lower concentration until they reach equilibrium.
Where does diffusion occur in the body?
And what is being diffused?
Between blood and the cells in your body
Diffuses glucose and oxygen into cells that need them
How do you increase the rate of diffusion?
Decrease the distance the particles need to move
Increase the concentration gradient
Increase the surface area
What is osmosis?
The special type of diffusion of water molecules across a selectively permeable cell membrane
What is water potential?
The concentration of free water molecules
What substance has the highest possible water potential?
Pure water
What is active transport?
Allows cells to move substances from an area of low concentration to high concentration against their concentration gradient
How can particles move against the concentration gradient in active transport?
Energy must be transferred from an energy store
What are the three key features of active transport?
Particles transported against concentration gradient
ATP required - comes from respiration
Makes use of carrier proteins in the cell membrane
How do cells adapt to carrying out active transport?
More mitochondria
What does the rate of active transport depend on?
Rate of respiration to produce the required ATP
What are carrier proteins?
Special proteins that span across the width of the cell membrane that can change shape or rotate to transport the molecule into the cell
What are some examples of active transport?
Digestion - glucose transferred into the bloodstream via the villi
Nerve cells - pumps sodium ions out and potassium ions in for creating nerve impulses
Root hair cells - taking in water and mineral ions
What is mitosis?
The process by which body cells divide to produce two identical daughter cells
Why do humans need mitosis?
It grows the cells we need to grow bigger and to replace the dead cells