Cell and movement across membrane Flashcards
What is diffusion?
The movement of particles from a high area of concentration to a low area of concentration across a partially permeable membrane. Doesn’t require energy.
What 4 factors affect the rate of diffusion?
Temperature.
Decrease the distance of diffusion.
Increase S.A.
Increase rate of concentration gradient.
What is an example of diffusion in plant cells?
CO2 enters the stomata and oxygen moves out of cells by diffusion.
Define osmosis.
The movement of water through a partially permeable membrane from a higher water potential to a lower water potential. Doesn’t require energy.
Example of osmosis.
Reabsorption of water in the kidneys.
What does hypotonic mean?
More dilute solution outside the cell.
What does hypertonic mean?
More concentrated solution outside the cell.
How do you find the change in mass
(Final mass - Initial mass) / Initial mass x 100
Define active transport.
Allows cells to move substances from an area of low concentration to an area of high concentration. Energy is required.
Example of active transport.
Nutrients in the soil moves from low to high concentration into the hair cells.
Define mitosis.
A type of cell division which produces daughter cells identical to the parent.
What are the 3 stages of the cell cycle?
Interphase.
Mitosis.
Cytokinesis.
What is interphase?
The replication of the cell, ready for mitosis.
What is prophase?
Where the nucleus membrane breaks down.
What is metaphase?
When the chromosomes align across the centre of the cell.
What is anaphase?
When one copy of each chromosomes move to opposite ends of the cell.