| what is the function of the cell membrane | controls entry and exit of molecules to cells |
| the cell membrane is ____ _____ | selectively permeable |
| define "selectively permeable" | it will only allow the passage of smaller, soluble molecules through the membrane |
| what does the cell membrane consist of? | proteins
phospholipids |
| what is A in this diagram | Protein |
| what is B in this diagram | Phospholipid |
| what is meant by bilayer? | structure composed of two layers of molecules |
| where in the cell membrane will small molecules like oxygen, co2 and water go through? | phospholipid bilayer |
| where in the membrane will large molecules like glucose go through? | channel forming proteins
so they can move through the membrane in a pore |
| what is the function of other proteins in the cell membrane? | act as carriers to transport molecules and ions across the membrane |
| What is diffusion? | the movement of molecules from a region of higher concentration of the molecule to a region of lower concentration |
| what kind of transport is diffusion an example of? | passive transport |
| does diffusion require energy? | no |
| what is a concentration gradient? | different between two concentrations |
| which side has a high concentration? | left |
| which side has a low concentration | right |
| looking at this diagram, which way will molecules travel during diffusion | left to right |
| during diffusion, in which direction do individual molecules move | randomly |
| what substances to cells require | glucose
oxygen |
| why do substances require glucose and oxygen | so they can release energy during aerobic respiration |
| what waste product to cells make during aerobic respiration | carbon dioxide |
| what must happen to waste products in cells in order for them to stay alive | they must diffuse out of cells |
| diffusion occurs with how many substances at a time? | one only |
| what is osmosis? | the movement of water molecules from a region of higher water concentration to a region of lower water concentration |
| what type of process is osmosis? | passive process |
| does osmosis require energy | no |
| what type of membrane does osmosis take place through | a selectively permeable membrane |
| what happens when a soluble substance dissolves in water? | its molecules spread out into the spaces between the water molecules |
| what must be present for osmosis to occur? | a membrane |
| what is the size of soluble molecules | small |
| what is the size of insoluble molecules | large |
| what is a solvent? | a substance that is able to dissolve other substances |
| what is a solute? | a substance that is dissolved in the solvent |
| what happens when a cell is placed in a substance with a higher salt and lower water concentration compared to the cell | it will become plasmolysed |
| what happens when a cell is placed in a substance with a higher water but lower salt concentration compared to the cell? | it will become turgid |
| what is active transport | the movement of ions and molecules through the cell membrane from a lower concentration of the ions/molecules to a higher concentration of the ions/molecules |
| what does active transport require? | energy from atp |
