Question | Answer |
What is Diffusion | The movement of molecules of a substance FROM their area of HIGHER concentration TO their area of LOWER concentration until they are evenly spread. |
What happens to the rate of diffusion when there is a steeper concentration gradient | It is faster |
Name 2 substances that diffuse INTO cells in the tissues | Oxygen,
Glucose,
Amino Acids,
Water |
Name 2 substances that can diffuse out of cells in the tissues | Carbon dioxide,
Urea
Water |
What do you call the holes found in cell membranes | Pores (or channels) |
What size must molecules be to be able to diffuse into and out of cells | Small |
What is the name we give to a membrane that chooses what can pass through it? | Selectively permeable |
What are the names of the 2 different types of molecule which make up the cell membrane | Phospho-lipid molecules,
Protein molecules |
Is diffusion Active or Passive | Passive |
What does Passive mean | Does not require Energy |
What is Osmosis | The name for the diffusion of water |
Define Osmosis | Osmosis is the movement of WATER molecules from their area of higher water concentration to their area of lower water concentration THROUGH A SELECTIVELY PERMEABLE MEMBRANE. |
Is Osmosis Active or Passive | Passive |
Define Active transport | The movement of molecules AGAINST their concentration gradient from an area of LOWER concentration to an area of HIGHER concentration. |
Does Active Transport require energy? | Yes |
What happens to ALL cells when placed in 100% water? | They GAIN mass by osmosis. |
What happens to ALL cells when placed in a solutions of a lower water concentration? | They LOSE mass by osmosis. |
What happens to ALL cells when placed in a solution with the same water concentration as their cytoplasm? | Nothing |
What eventually happens to animal cells in solutions with a water concentration GREATER than the cell cytoplasm? | BURST |
What eventually happens to animal cells placed in a solution with a water concentration LESS than the cell cytoplasm? | SHRIVEL |
What eventually happens to PLANT cells in solutions with a water concentration GREATER than the cell cytoplasm? | They swell up and become TURGID |
What eventually happens to PLANT cells in a solution with a water concentration LESS than the cell cytoplasm? | They shrivel and become PLASMOLYSED |
What direction do molecules or ions move during active transport? | Against the concentration gradient. |
What molecule must be present in the cell membrane for active transport? | Protein |
Does active transport need energy? | Yes |
Name a molecule or ion that can be moved into or out of a cell by active transport. | Sodium or Potassium or Iodine |