Term
| Biological membranes consist of _________ and _____________. |
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Definition
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Term
| What are the two main lipids seen in membranes? |
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Definition
| Phospholipids and sterols |
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Term
| Which lipid is the most abundant in membranes? |
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Definition
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Term
| The main sterol in animal cell membranes is |
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Definition
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Term
| Why is it important to prevent membranes from freezing? |
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Definition
| Freezing can kill cells by stopping membrane functions |
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Term
| How do animal cells prevent their membranes from being frozen? |
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Definition
| Increase the amount of cholesterol |
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Term
| How do plant cells prevent their membranes from being frozen? |
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Definition
| increase the amount of unsaturated fats in membrane |
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Term
| What are the different kinds of membrane proteins a cell may have? |
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Definition
Transport proteins
Recognition proteins
Receptor proteins
Cell adhesion proteins
Enzymes |
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Term
| What does the fluid mosaic model propose? |
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Definition
| The membrane consists of fluid phospholipid bilayer in which proteins are embedded and float freely |
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Term
| The ones embedded within the bilayer of the membrane are called |
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Definition
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Term
| The ones held to the membrane surfaces by covalent bonds are called |
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Definition
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Term
| Passive transport is when ions and molecules move ? the concentration gradient. |
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Definition
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Term
Active transport is when ions and molecules move ? the concentration gradient
using ATP. |
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Definition
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Term
| What is concentration gradient? |
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Definition
| Movement of ions or molecules from a region of higher concentration to a region of lower concentration |
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Term
| What can move through the membranes easily? |
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Definition
| Hydrophobic (nonpolar) molecules |
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Term
| What cannot move through very easily? |
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Definition
| Hydrophilic molecules (ions and polar momecules) |
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Term
| What cannot move through the membranes at all? |
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Definition
| Charged atoms and molecules |
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Term
| Ions and molecules can be transported across membranes by using |
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Definition
1. simple diffusion
2. facilitated diffusion
3. osmosis
4. active transport |
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Term
| What is simple diffusion? |
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Definition
| Diffusion through the lipid part of a biological membrane |
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Term
| What is facilitated diffusion? |
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Definition
| Diffusion of polar and charged molecules through transport proteins |
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Term
| What are the two kinds of transport proteins used here? |
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Definition
| Channel proteins , carrier proteins |
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Term
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Definition
| chloride ions cannot be pumped out of epithelial cells causing build up of mucus |
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Term
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Definition
| amino acids can’t pass through kidney cell membranes causing the formation of kidney stones |
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Term
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Definition
| lack of functional photopigment proteins in the cell membranes within photoreceptor cells |
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Term
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Definition
| Diffusion of water across a selectively permeable membrane in response to concentration gradients |
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Term
| What is happening during the following tonicity: |
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Definition
Isotonic
Hypertonic
Hypotonic |
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Term
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Definition
| solution has less solute than the cell, water enters the cell causing it to swell |
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Term
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Definition
| solution surrounding a cells contains more solutes than the cell, water leaving the cell causing it to shrinks |
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Term
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Definition
| concentrations of solutes inside and outside the cell is balanced, no water movement |
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Term
| During exocytosis, the cell is doing what? |
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Definition
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Term
During endocytosis?
the cell is doing what? |
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Definition
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Term
| What are the three pathways of endocytosis? |
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Definition
Pinocytosis
Receptor mediated endocytosis
Phagocytosis |
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Term
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Definition
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Term
| Receptor mediated endocytosis |
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Definition
| target molecules are bound to receptor proteins on the outer cell surface |
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Term
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Definition
| take in large particles or whole cells |
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