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BIO120-Membrane
BC-Membrane Structure & Function
| Question | Answer |
|---|---|
| The term for membranes which allow some molecules to pass through while blocking passage of other molecules. | Selective Permeability |
| Another name for passive transport. | Facilitated Diffusion |
| This term describes equal solute concentrations inside and outside of the cell. | isotonic |
| When the solute concentration is less. | Hypotonic |
| Small sacs (circles) of membrane are called _______. | vesicles |
| This is the diffusion of water across a semi-permeable membrane. | Osmosis |
| Which region of the phospholipid molecule is hydrophyllic? | The Glycerol Head |
| Is it the proteins or the fatty acid tails which are responsible for giving the "Fluid Mosaic Model" of the plasma membrane its MOSAIC portion of the name? | The insertion of the proteins. |
| A cell with an internal salt concentration of 0.1% salt is placed in a solution of 2% salt solution. Is the solution surrounding the cell considered hypotonic or hypertonic? | The solution surrounding the cell is considered hypertonic . |
| Does diffusion move molecules down or up the concentration gradient? | Down |
| The process a cell uses to bring particles into the cell by pinching off a small circle of membrane to form a vesicle enclosing the particles. | Endocytosis |
| In a solution consisting of salt dissolved in water, which is the solute? | salt |
| Which region of the phospholipid molecule are hydrophobic? | Fatty Acid Tails |
| This term describes conditions when the solute concentration is greater. | Hypertonic |
| This method of moving molecules across the membrane uses proteins embedded in the membrane, and uses ATP energy to move molecules against (up) the concentration gradient. | Active Transport |
| A cell with an internal salt concentration of 0.1% salt is placed in a solution of 0.2% salt solution. Which way will water move, into or out of the cell? | Out of the cell. |
| Diffusion is considered to be _______ ________ because no transport proteins are involved and no ATP energy is used. | Passive Transport |
| Is the glycerol head of a phospholipid molecule polar or non-polar? | Polar |
| The process whereby vesicles fuse with the plasma membrane and are able to "dump" the contents to the outside of the cell. | Exocytosis |
| A cell with an internal salt concentration of 0.3% salt is placed in a solution of 0.2% salt solution. Which way will water move, into or out of the cell? | Into the cell |
| Hydrocarbon tails of fatty acids which are saturated will or will not pack tightly together? | They will pack tightly together. |
| Hydrocarbon tails of fatty acids which are UNsaturated will or will not pack tightly together? | They will not pack tightly together. |
| HIV uses which types of membrane protein to attach to immune cells? | CD4 and CCR-5 cell surface proteins |
| These membrane carbohydrates have lipids bonded to them. | Glycolipids |
| These membrane carbohydrates have proteins bonded to them. | Glycoproteins |
| Molecules like diatomic oxygen are _____ and _____ and can pass easily through the membrane. | Nonpolar; hydrophobic |
| Molecules like sugars and water are _____ and _____ and cannot pass easily through the membrane. | Polar; hydrophyllic |
| The interior of the plasma membrane is considered to be _______ due to the non polar nature of the fatty acid tails. | Hydrophobic |
| The exterior of the plasma membrane is considered to be _______ due to the polar nature of the glycerol heads. | Hydrophyllic |
| Which type of transport protein has a tunnel that is hydrophillic? | Channel |
| ______ proteins can bind to molecules and change shape to transfer them across the membrane. | Carrier |
| What are the two types of transport proteins? | Channel and Carrier |
| This is the movement of like molecules down their concentration gradient. | Diffusion |
| _______ transport moves molecules against their concentration gradient and uses carrier proteins. | Active Transport |
| _______ diffusion uses membrane proteins and no ATP energy to move molecules down the concentration gradient. | Facilitated |
| In osmosis water will always move _______ the hypertonic solution across the membrane. | Into |
| Plant cells become ______ or firm when placed in a hypotonic solution. | Turgid |
| What portion of the plant cell is responsible for the fact that the cell does not burst when placed in a hypotonic solution? | Cell wall |
| When the plasma membrane pulls away from the cell wall in a plant cell that is placed in a hypertonic solution, it is known as: | Plasmolysis |
| ______ is a type of endocytosis in which a cell engulfs a particle by extending pseudopodia around it and creating a food vacuole. | Phagocytosis |
| ______ is a type of endocytosis in which a cell obtains fluid by creating vesicles around the fluid. | Pinocytosis |