Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
15 Cards in this Set
- Front
- Back
|
What is the structure of the cell membrane? |
The cell membrane is made up of proteins and phospholipids |
|
|
What does selectively permeable mean? |
That the cell membrane allows small molecules to pass through, like oxygen and glucose, and stops large molecules like starch from passing through |
|
|
What does passive transport mean? |
Requires energy and occurs due to different concentrations of substances between the cell and its external environment. This is called a concentration gradient. |
|
|
What are two types of passive transport? |
Osmosis and Diffusion |
|
|
What is diffusion? |
The movement of molecules down a concentration gradient from a high concentration to a low concentration |
|
|
Why is diffusion important in animals and plants? |
•Stomata of leaves carbon dioxide diffuses into the leaf from a higher concentration in the air to a lower concentration in the leaf •Villi of the digestive system glucose diffuses into the blood capillaries from a higher concentration in the villus to a lower concentration in the blood capillaries •Alveolus of the respiratory system oxygen diffuses into the blood capillaries from a higher concentration in the air sac to a lower concentration in the blood capillaries |
|
|
What is osmosis? |
The movement of water molecules from a high water concentration to a low water concentration through a selectively permeable membrane |
|
|
What is the effect of osmosis on plant cells when placed in a low water concentration? |
The cell becomes plasmolysed |
|
|
What is the effect of osmosis on plant cells when placed in a water/solute concentration equal to the cell? |
Nothing/ the cell stays normal |
|
|
What is the effect of osmosis on plant cells when placed in a high water concentration? |
It becomes turgid as the cell wall prevents the plant cell from busting |
|
|
What is the effect of osmosis on animal cells when placed in a solution with a low water concentration? |
The cell becomes shrivelled |
|
|
What is the effect of osmosis on animal cells when placed in a water/ solute concentration equal to the cell? |
Nothing/ cell stays normal |
|
|
What is the effect of osmosis on animal cells when placed in a solution with a high water concentration? |
The cell will burst |
|
|
What is active transport? |
The movement of molecules and ions from a low concentration to a high concentration. Membrane proteins are responsible for moving molecules and ions against the concentration gradient, this requires energy. |
|
|
What are the differences between active and passive transport? |
Active transport requires energy, where passive transport doesn’t, and Active transport is the movement against the concentration gradient, where passive transport isn’t |
