Bio 004, College of the Desert

Energy: Capacity to perform work.

Kinetic energy: Energy in motion, (water flowing over a dam).

Potential energy: stored energy, (water stored behind the dam).

Principle of Conservation of energy: energy can neither be created nor destroyed, but can only be converted from one form to another.

Entropy: measure of disorder or randomness. Every time energy is converted from one form to another, entropy increases.

• Chemical energy: energy that arises from the arrangement of atoms. ie: Carbohydrates, fats, and hydrocarbons tend to be especially rich in chemical energy.
• 1. automobile engines; 25% efficiency of converting chemical to kinetic energy. [75%converted to heat].
• 2. 40% efficiency converting chemical to kinetic energy. [60% converted to heat].

Calorie: the amount of energy required to raise one gram of water one degree.

• Adenosine triphosphate (ATP): Energy ex-change currency in all living organisms. Composed of adenine (molecule found in DNA), ribose (sugar found in RNA), and three phosphate groups (PO₄).
• 1. When phosphate bonds are broken, energy is released.
• 2. When phosphate bonds are formed, energy is stored.

Energy coupling: transfer of energy from process that produce energy to processes that consume energy.

Metabolism: Sum total of all chemical reactions in an organism.

Enzymes: specialized protien molecules that increase the rate of a chemical reaction.

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• Activation energy: Amount of energy requires to begin a chemical reaction destabalizes reactants in order to make them more likely to react.

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• By reducing the amount of activation energy required to destabilize reactants, metabolism occurs at cooler temperatures.

Enzyme: chemical that increases the rate of a chemical reaction without increasing the temperature.

Substrate: Molecule with which the enzyme reacts; specific enzyme to a specific substrate (reactant).

Enzyme-substrate complex: temporary molecule formed when an enzyme attaches to a substrate.

Active site: specific region of the enzyme that has a shape and chemistry that fits the substrate molecule.

Induced fit: When entry of the substrate into the enzyme causes the enzyme to change its shape in order to embrace the substrate and catalyze the reaction.

• Inhibitor: A molecule that attraches to an enzyme interfering with its ability to form an enzyme-substrate complex.

Nagative feedback regulation: as the amount of end product increases, end product molecules inhibit a prior reaction stopping the progression of the reaction.

• Positive feedback regulation: as
• the amount of end product increases, end product molecules stimulate a prior reaction promoting the progression of the of the reaction.

Diffusion: movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis: diffusion of molecules across a selectively permeable membrane.

Concentration gradient: difference in number of molecules in a given area.

Dynamic equilibrium: when molecules be-come evenly dispersed while moving equally in all areas.

Passive transport: movement of molecules in which the cell expends no energy.

Facilitated diffusion: increase in the rate of diffusion with assistance from transport proteins.

Isotonic: Solution in which the concentration of water and dissolved materials is equal between a cell and its surroundings.

Hypertonic: solution with more dissolved materials than water.

Hypotonic: Solution with less dissolved materials then water.

Plasmolysis: in a hypertonic solution, a plant cell loses water and the plasma membrane pulls away from the cell wall. [usually result in the cells death].

Active transport: When energy is required to move molecules across a cells membrane against the concentration gradient.

Exocytosis: movement of molecules out of the cytoplasm by vesicles or vacuoles.

Endocytosis: Movement of molecules into the cytoplasm by vesicles or vacuoles.

Phagocytosis: Cell engulfs a particle and packages it within a food vacuole.

Pinocytosis: Cell gulps droplets of fluid by forming tiny vesicles.