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15 Cards in this Set
- Front
- Back
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What are the 3 main principles of cell theory? |
- All organisms are composed of one or more cells - Cells are the smallest units of life - All cells come from pre-existing cells |
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In what ways are cells limited by size? |
Surface are to volume ration. This ratio must be high so that adequate amounts of necessary materials can enter the cell and wastes can escape the cell so there is no waste toxicity build-up. |
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What are stem cells? What are pluripotent stem cells? |
Cell that retain their ability to divide and differentiate into various cell types. Pluripotent stem cells, also known as embryonic stem cells, can form any type of cell in an organism. |
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Name features of a prokaryotic cell. |
- Cell wall, made of peptidoglycan - Plasma membrane - Flagella - Ribosomes - Nucleoid |
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Describe a eukaryotic cell. |
- Range in diameter from 5 - 100 micrometres - Have organelles and are complex - DNA + histones = chromosomes - Ribosomes (larger than prokaryotes) - Plant and Animal |
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What are cellular membranes made of? |
Phospholipids and proteins. Structure is the 'fluid mosaic model'. |
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Name some general functions of membrane proteins. |
- Hormone binding sites - Cell adhesion - Cell-to-cell communication - Channels for passive transport - Pumps for active transport |
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Why is the sodium potassium pump important? |
It ensures proper ion levels within nerves and muscles so they can operate efficiently. |
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What is the difference between active and passive transport? |
Passive transport involves no expenditure of energy on the part of the cell. Includes diffusion, facilitated diffusion, and osmosis. Active transport requires expenditure of energy. Includes sodium-potassium pump, endocytosis, and exocytosis. |
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What is the difference between endocytosis and exocytosis? |
Endocytosis occurs when a portion of the plasma membrane is pinched off the enclose macromolecules or particulates needed by the cell. A vesicle is formed inside the cell. Exocytosis is essentially the opposite but involves the Golgi apparatus. |
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Describe the key parts of the cell cycle. |
- Cell division - G1 - S - G2 (G1 - G2 is in interphase) - M (mitosis) - Cytokinesis |
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Describe Mitosis. |
1. Prophase: chromosomes become visible, nuclear membrane disappears. 2. Metaphase: chromosomes line up along equator, spindle attaches to chromosome centromeres. 3. Anaphase: individual chromatids of chromosomes split and move to opposite poles of cell. 4. Telophase: nuclear membrane reforms, cytokinesis begins. |
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Compare cytokinesis in plant and animal cells. |
Plant: a cell plate forms inside the cell and spreads out. Animal: the plasma membrane is pinched in resulting in a cleavage furrow. |
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Compared to the eukaryotic cell cycle, how do prokaryotic cells divide? |
Binary fission. |
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Tumours are the result of what? |
Uncontrolled cell division. They may occur in any tissue or organ. |
