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55 Cards in this Set
- Front
- Back
What are the 3 main components of a cell? |
Cell membrane, cytoplasm, nucleus. |
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What is the cell membrane? |
The outermost covering surrounding the cytoplasm and help maintain cell shape. |
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What is a semi permeable membrane? |
Allows only selective substances to move in or out of the cell by osmosis or diffusion. |
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What is the cell membrane made up of? |
Tri lamellar structure made of phospholipids and glycoproteins. |
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What are passive channels? |
Remain open all the time, ions can move freely across the membrane. (Na+ and K+ channels) |
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What are active channels? |
Gated channels, classified into 2 types. |
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What are voltage regulated channels? |
Open gates to allow ions to exchange across cell membrane, only if change in voltage. Found in nerve cells and muscle cells. |
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What are chemically regulated channels? |
Respond to certain chemicals produced by the body. Located in cell membranes at synapses. |
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What are chemically regulated channels? |
Respond to certain chemicals produced by the body. Located in cell membranes at synapses. |
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What does the cytoplasm consist of? |
Mitochondria, ribosomes, endoplasmic reticulum, lysosomes, golgi apparatus, centrosome, vacuoles. |
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What is the mitochondria? |
"Powerhouse of cell". Help produce energy in form of ATPS. Responsible for internal respiration at cellular level (exchange of gases). |
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What is the mitochondria? |
"Powerhouse of cell". Help produce energy in form of ATPS. Responsible for internal respiration at cellular level (exchange of gases). |
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What are the ribosomes? |
Small granular particles in cytoplasm. Made up of 60% RNA and 40% protein. Found in free form as well as endoplasmic reticulum. Main function is protein synthesis. |
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What is the endoplasmic reticulum? |
Network of double walled tubules. They help in synthesis of lipids and fatty acids, help transport proteins. |
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What are the lysosomes? |
These are small vesicles containing enzymes. These are also known as "digestive organs" of the cell. Help break down proteins, carbs, and fats. |
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What is the golgi apparatus? |
Between cell membrane and nucleus, helps in distribution of proteins, lipids, and other substances to diff location within or outside of the cell. |
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What are the centrosomes? |
Made up of 9 bundles, each bundle having three tubules. Responsible for spindle formation during cell division. |
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DNA |
Double helix structure made up of nucleotides held together by hydrogen bonds. Carries genetic info. |
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mRNA |
Messenger RNA. Carries messages from nucleus to ribosomes. |
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rRNA |
Decodes info, identifies amino acid needed to make specific protein. |
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tRNA |
Carries a specific amino acid to the proper place to build an amino acid chain. |
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Important properties of cells |
Growth, Reproduction, Absorption, Metabolism, Excretion, Secretion and Irritability. |
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Hypertrophy |
Increase in the size of a cell or organ beyond its normal size. |
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Hyperplasia |
Increase in the size of an organ due to increase in number of cells. |
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Atrophy |
A decrease in size of an organ from its normal size. |
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Aplasia |
If a tissue or organ fails to develop completely. |
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Mitosis |
Division of the cell to produce the two daughter cells with exact copy of mother's genetic material. Diploid cells - same # of chromosomes as mother cell. |
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Meiosis |
Number of chromosomes is reduced to half in daughter cells (haploid). Sperm and Ova produced with meiosis. |
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What are the 2 types of absorption processes? |
Phagocytosis: (Cell eating) and Pinocytosis: (Cell drinking) |
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Secretion |
Release of useful substances by the cells. Certain cells secrete proteins and enzymes by exocytosis, opposite of pinocytosis. |
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Excretion |
Elimination of waste products by the cells |
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Metabolism |
The sum total of all biochemical reactions taking place in all the cells in body. |
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Catabolism |
Substances are broken down into simple units to release energy. E.g. Glucose + O2 → CO2 + Water + Energy. |
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Anabolism |
Making complex substances from simple units. These are synthesized depending on nutritional requirements of the cells. |
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Irritability |
Property of cell to respond to a stimulus.*The muscle cells have property to contract when stimulated |
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Active Transportation |
Movement of molecules through a membrane against their concentration gradient. |
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Passive Transportation |
Particles move across the plasma membrane without utilizing the cell energy. i.e. they utilize their own kinetic energy to move from an area of higher concentration to lower concentration. |
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Osmosis |
Movement of water across a semi permeable membrane. |
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Diffusion |
Movement of dissolved particles across the membrane from an area of higher concentration to an area of lower concentration. |
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Facilitated diffusion |
For big molecules like proteins that can't easily pass through the membrane. |
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Chemical composition of cells |
Water: 85% Proteins: 10% Lipids: 2% Carbohydrates:1.5% Inorganics: 1.5% |
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Water in cells |
40% - Intracellular fluid (fluid inside the cell) 15% - Interstitial fluid (synovial fluid in joints, serous fluid in visceral spaces, lymph, fluid between the cells etc.) 5% - Intravascular fluid (plasma) |
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Isotonic Fluids |
A fluid has the same number of particles (osmolality 275-300 mOsm/L) as of body fluids. *Normal saline |
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Hypertonic Fluids |
Higher osmolality than body cells or body fluids. *10% dextrose. |
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Hypotonic Fluids |
Lower osmolality than body cells or body fluids. *D5W |
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Crystalloids |
Dissolve in water. *salt in water. Can easily move from one compartment to another. Replacement fluids and maintenance. |
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Colloids |
Do not dissolve in water but can be suspended. *Peanut butter is suspension of solid in oil. Large molecules that cannot easily move. |
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Proteins |
Large molecules made up of amino acids. |
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Non-essential amino acids |
Produced by the body in sufficient quantity like cystine and glycine. |
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Essential amino acids |
Not synthesized by the body in sufficient amount and must be added in the food to ensure normal growth. e.g. lysin, tryptophen. |
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Structural Proteins |
Help in building body structures like collagen, elastin and keratin |
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Reactive Proteins |
Needed for various biochemical reactions in body. E.g. enzyme, protein hormones, hemoglobin. |
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Lipids |
Fats and related substances. These are non-soluble in water. Long chain of carbon atoms with hydrogen and oxygen atoms attached to them. |
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Carbohydrates |
Contain carbon, hydrogen, and oxygen atoms. |
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Inorganic ions |
Very important to maintain the pH and to regulate the osmotic pressure of the cells. |