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Description
Flashcards by dominique22, updated more than 1 year ago
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Created by dominique22
over 10 years ago
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| Question | Answer |
| What is Diffusion? | the movement of particles down a concentration gradient |
| What factors affect the speed of diffusion? | -as the temperature INCREASES, the rate of diffusion INCREASES |
| Where does diffusion happen faster? | in smaller molecules |
| If you have a box filled with a type of gas (i.e. bromine), and there's a wall between the 2 sides of the box. Side A (left) has more than Side B (right). What would happen if you removed the wall? | The particles would diffuse from A to B, and somewould be on each side. |
| What is the overall movement of this example of dffusion? | High to low concetration |
| Is this always the case? Explain why. | No, because some types of diffusion can move from low concentration to high concentration and high concentration to low concentration. In BOTH DIRECTIONS!!! |
| What would happen if the box is left for a while? | EQUAL Concentrations on both sides and NO movement from the particles. Although, they can move in BOTH directions. |
| Where is diffusion relatively fast? | -in SMALLER molecules |
| What would happen if cells were large?? | The cell's center would die by the time the substance has arrived. |
| Why do we have systems in larger organisms? What processes do they help? | - To transport molecules throughout the body at a faster pace than diffusion because we are mostly made of water (which is a liquid= slower) **EXAMPLES: (e.g. gas exchange, absorbing fod molecules from the intestines to the blood, excretory system, etc.) |
| List the properties of a cell memebrane. | -very thin -DOES NOT support the shape of a cell -flexible |
| List the parts of a cell membrane. | Hydrophilic Region (water loving) Hydrophobic layer (water fearing) transport protein |
| What is the cell membrane? | -the part of the cell that controls what goes in and out of the cell |
| Give the definition of this word: PERMEABLE | -to allow to come in |
| Give the definition of this word: IMPERMEABLE | -not able to pass through |
| Give the definition of this word: SELECTIVELY PERMEABLE | -to control what goes in and out -let some substances in, but not others |
| It depends of the properties of FAT and PROTEINS, whether a substance can enter a cell or not. T or F | TRUE!!! :) |
| What are the four types of diffusion? | Simple, Facilitated, Active transport, and bulk transport |
| What is simple diffusion? | When molecules diffuse down the fatty layer of the membrane. |
| Can Simple Diffusion transport UP a concentration gradient? | No, it can only move down the gradient; from high concentration to low concentration. |
| True or False: Simple Diffusion is a passive process. | True, it requires no energy :) |
| What does simple diffusion use to transport? | Molecules diffusing through the fatty layer of the membrane |
| What is simple diffusion used for? | Fat soluble molecules. |
| List the size and some examples of material that simple diffusion can process. | Smaller sized (e.g. oxygen, carbon dioxide) and Medium sized molecules (e.g. cholesterol) |
| What is Facilitated diffusion? | When protein carriers help diffuse a substance the cell membrane |
| Is Facilitated diffusion specific? | Yes, it is only down a certain channel pathway and only works for one type of material. |
| Facilitated diffusion a not passive process. T or F | False, it is a passive process that requires no energy. |
| List the things that facilitated diffusion can transfer. | Small water soluble ions (e.g. salt) and Medium sized water soluble ions (e.g. glucose, amino acids) |
| What is active transport? | Protein carrier molecules can pump a substance UP the concentration gradient (it can also go in DOWN in both directions) |
| List the characteristics of active transport. | -Carriers are specific -opposite of facilitated diffusion (travels UP instead DOWN the concentration) -moves water soluble ions (e.g. salt, glucose, animo acids, etc.) -NOT A PASSIVE PROCESS requires ENERGY!!! |
| What is bulk transport? | When molecules that are too big to pass through the membrane and vesicles (small sacs of membrane) detach themselves from the cell membrane and fuse back together after it has engulfed the protein molecule. |
| What is special about Bulk Transport? | This process is very organised and IS NOT a passive process!! |
| What is Endocytosis? | transporting large molecules into the cell using vesicles |
| What is Exocytosis? | removing large molecules from the cell using vesicles |
| What are the 2 types of Endocytosis? | Phagocytosis (cell eating) and Pinocytosis (cell drinking) |
| List the characteristics of Phagocytosis | -uses large vesicles to take in other large solid objects (e.g. other cells) -if the cell that is taken is feeding on another cell, it is called a food vacuole (e.g. a human blood cell eating a diseased- causing bacterium.) |
| List the characteristics of Pinocytosis | Uses small vesicles to take in large molecules or liquids |
| What is OSMOSIS? | the diffusion of water through a permeable membrane from high to low concentration until a balance is reached |
| What are osmosis model cells? | they are made of cellulose tubing that are selectively permeable |
| Model Cells are very permeable to small molecules like water. T or F | True!! |
| What are they less permeable to? | large molecules (e.g. glucose) |
| Blood cells are impermeable to water. T or F | False, they are very permeable to water |
| What is another component they are relatively impermeable to? | ions in salt solutions |
| If a blood cell is in a hypotonic solution, what will happen? | The cell will SWELL because there is more water inside the cell than the concentration outside so it is not affected and will take in water. |
| If a blood cell is in a hypertonic solution, what will happen? | There is more of the solution than the water that is inside the cytoplasm of the cell, so the water is going to leave the cell by osmosis. Hence, the cell will SHRINK!!! |
| What if it was placed in a ISOTONIC solution? | Nothing would happen and there would be equal movement between both. This is because there is a balance between the components inside and outside the cell. |
| What makes plant cells different from animal cells? | They have a cell wall |
| What makes a plant, "TURGID?" | When placed in an environment that has a good supply of water, which will make the cell swell up and become FIRM and HARD :) |
| Why is turgidity of a plant so important? | Being turgid, helps to support the soft parts of plants. |
| What makes a plant, "FLACCID?" | When in a HYPERTONIC solution, the plant cell loses water by osmosis. Hence, the plant will WILT and become DROOPY! |
| What is the term used to explain how, 'the cell shrinks away from the plant's wall'? | Plasmolysed (the process is called, Plasmolysis) |
| How do the molecules move? | In constant random movements |
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