Energy Flow, Diffusion/Osmosis, and Enzyme Regulation Vocabulary

Vocabulary flashcards covering key concepts from energy transformations, trophic levels, diffusion/osmosis, tonicity, and enzyme regulation discussed in the lecture.

Entropy

A measure of disorder in a system; natural processes tend to move from order to disorder, and reversing this requires input of energy.

10% Rule (Trophic Level Energy Transfer)

Approximately 90% of energy is lost between trophic levels; about 10% is transferred to the next level, limiting the number of trophic levels.

Primary Production

The process of creating plant biomass (via photosynthesis) at the base of the food chain.

Trophic Level

A position in a food chain (e.g., producers, primary consumers, secondary consumers) that describes energy flow between levels.

Diffusion

Movement of particles from high to low concentration; spontaneous and does not require energy.

Semipermeable Membrane

A membrane that lets some substances pass while restricting others (e.g., dialysis tubing).

Osmosis

Diffusion of water across a semipermeable membrane from high to low water concentration, driven by solute differences (tonicity).

Hypertonic

A solution with a higher solute concentration relative to the reference side; water tends to move out of cells.

Hypotonic

A solution with a lower solute concentration relative to the reference side; water tends to move into cells.

Isotonic

A solution with equal solute concentration on both sides; no net water movement across the membrane.

Passive Transport

Transport that does not require energy; substances move down their concentration gradient.

Active Transport

Transport that requires energy; substances move against their concentration gradient (low to high).

Allosteric

Regulation of an enzyme by binding at a site other than the active site, changing enzyme activity.

Allosteric Site

The region on an enzyme where regulators bind to induce conformational changes affecting activity.

Competitive Inhibition

An inhibitor competes with the substrate for the enzyme’s active site, reducing reaction rate (can be overcome by more substrate).

Noncompetitive Inhibition

An inhibitor binds to an allosteric site, changing enzyme shape and reducing activity; cannot be overcome by more substrate.