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34 Cards in this Set
- Front
- Back
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What is diffusion?
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A passive process where molecules move from an area of high concentration of molecules to an area of low concentration of molecules.
*As molecules diffuse a state of equilibrium will occur. |
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What is simple diffusion?
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Molecules cross through the phospholipid bilayer.
-The membrane is permeable (allows molecules to pass) |
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What is osmosis?
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Diffusion of water through a selectively permeable membrane, which limits the diffusion of at least some of the solute particles.
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What is isotonic?
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Two fluids that have the same potential osmotic pressure.
Water will move in equal amounts. |
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What is hypertonic?
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When the intracellular fluid shrivels as water flows out of the cell to an area of higher concentration.
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What is hypotonic?
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When the cell swells because water flows into the cell because inside the cell has higher concentration.
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What is facilitated diffusion?
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Movement of molecules is made more efficient by the action of transporters embedded in a cell membrane.
Transports substances down a concentration gradient. Moves from high concentration to low concentration. |
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What are the two types of Facilitated Diffusion?
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Channel-mediated passive transport and Carrier-mediated passive transport.
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What is channel-mediated passive transport?
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Only allow one type of solute to pass through.
Gated channels may be open or closed and may be triggered by any variety of stimuli. Channels allow membranes to be selectively permeable. Aquaporins are water channels that permit rapid osmosis. |
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What is carrier-mediated passive transport?
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Carriers attract and bind to the solute, change shape, and release the solute out the other side of the carrier.
Carriers are usually reversable, depending on the direction of the concentration gradient. |
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What is active transport processes?
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Require the expenditure of metabolic energy by the cell.
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What are the four types of active transports?
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Pumps
Vesicles Endocytosis Exocytosis |
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What is transport by pumps?
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Pumps are membrane transporters that move a substance against its concentration gradient - the opposite of diffusion.
*Move from low to high |
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What is transport by vesicles?
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Allows substances to enter or leave the interior of a cell without actually moving through its plasma membrane.
*becomes one with the membrane. |
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What is endocytosis?
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The plasma membrane traps some extracellular material and brings it into the cell in a vesicle.
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What are the two types of endocytosis?
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Phagocytosis and Pinocytosis
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What is phagocytosis?
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Cell-Eating - Large particles are brought into the cell by vesicles and the vesicles fuse with lysosomes where the particles are digested.
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What is pinocytosis?
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Cell-drinking, fluid and the substances dissolved in it enter the cell.
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What is receptor-mediated endocytosis?
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Membrane receptor molecules recognize substances to be brought into the cell.
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What is exocytosis?
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Large molecules, notably proteins, can leave the cell even though they are too large to move through the plasma membrane.
Molecules are enclosed in vesicles that are then pulled by the cytoskeleton to the plasma membrane, where the contents are released. Exocytosis also provides a way for new material to be added to the plasma membrane. |
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What is catabolism?
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Breaks large molecules into smaller ones, usually releases energy.
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What is anabolism?
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builds large molecules from smaller ones, usually consumes energy.
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What do enzymes do?
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Enzymes are chemical catalysts, reducing activation energy needed for a reaction.
Enzymes regulate cell metabolism. |
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What is the chemical structure of enzymes?
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Proteins of a complex shape.
The active site is where the enzyme molecule fits the substrate molecule - the lock and key model. |
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How are enzymes classified and named?
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Usually have an -ase ending, with the first part of the word signifying the substrate or the type of reaction catalyzed.
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What are the general functions of enzymes?
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Enzymes regulate cell functions by regulating metabolic pathways.
Enzymes are specific in their function. Most enzymes catalyze a chemical reaction in both directions Enzymes are continually being destroyed and replaced. Many enzymes are first synthesized as inactive proenzymes. |
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What are allosteric effectors?
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Various chemical and physical agents that affect enzyme action by changing the shape of the enzyme molecule.
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What are some examples of allosteric effectors?
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Temperature
Hydrogen Ion Concentration Ionizing Radiation Cofactors End products of certain metabolic pathways |
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What are the two types of cell division?
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Mitotic Division (Mitosis) and Meiotic Division (Meiosis)
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What is Mitosis?
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Occurs in all body cells where daughter cells have same number of chromosomes (23 pairs of chromosomes) like mother cells.
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What is Meiosis?
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Where daughter cells have half the number of chromosomes (23 chromosomes) which occurs only in sex cells (ovum and sperm)
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What does cell growth depend on?
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Using genetic information in DNA to make the structural and functional proteins needed for cell survival.
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What is cell reproduction?
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Ensures that genetic information is passed from one generation to the next.
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What are the three phases of cell growth?
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Growth Phase (G1)
Synthesis Phase (S) Second Growth Phase (G2) |
