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Biology Chapter 5
Chapter 5 vocabulary 2
Term | Definition |
---|---|
Biochemical pathway | Metabolic pathway. Begin with a particular reactant and terminate with an end product. |
Enzymes | Usually protein molecules that function as organic catalysts to speed chemical reactions. |
Substrates | The reactant molecules that the enzyme acts on. |
Active site | Region on the surface of an enzyme where the substrate binds and where the reaction occurs. |
Energy of activation (Ea) | The energy needed to cause molecules to react with one another. |
Feedback inhibition | Mechanism for regulating metabolic pathways in which concentration of the product is kept within a certain range until binding of the substrate to the enzymes active site reduces or stops the activity of the pathway. |
Diffusion | molecules move down their concentration gradient until equilibrium is achieved and are distributed equally. |
Solution | Contains both a solute and a solvent. |
Solute | Usually solids or gases like dyes. |
Solvent | Usually liquids |
Facilitated diffusion | Molecules diffuse across a plasma membrane through a channel protein or with the assistance of carrier proteins. |
Aquaporins | Channel proteins for water |
Osmosis | Is the diffusion of water across semipermeable membrane from an area of high concentration to an area of lower concentration. Often uses aquaporins. |
Hypotonic solution | Water moves from areas of low solute concentration. |
Hypertonic solution | Water moves from areas of high solute concentration. |
Isotonic solution | Have equal solute concentrations; the cell never gains or loses water. |
Lysis | Disrupted cells. |
Hemolysis | Disrupted red blood cells. |
Selectively permeable | Certain substances that can freely pass through the membrane, some are transported across, others are prohibited from entering or leaving. |
Passive transport | Substances move from an area of higher concentration to an area of lower concentration and no energy is required. |