Membrane Transport and Energy in Biology

These flashcards cover key vocabulary related to membrane transport mechanisms, energy concepts, and enzyme dynamics as discussed in the lecture.

Membrane Transport

The process by which substances move across cell membranes, including mechanisms like diffusion and active transport.

Diffusion

A passive transport mechanism where molecules move from an area of higher concentration to an area of lower concentration.

Active Transport

An energy-dependent process that moves substances against their concentration gradient.

Endocytosis

The process of taking material into the cell by means of infolding of the cell membrane.

Exocytosis

The process by which a cell releases large amounts of material through vesicles that fuse with the membrane.

ATP

Adenosine triphosphate; the primary energy carrier in cells.

Kinetic Energy

The energy of an object due to its motion.

Potential Energy

The stored energy of an object due to its position or arrangement.

Entropy

A measure of disorder or randomness in a system; indicates the amount of energy available to do work.

Endergonic Reactions

Reactions that require energy input to occur, often associated with cellular work.

Exergonic Reactions

Reactions that release energy, commonly associated with catabolic processes.

Enzyme

A biological catalyst that speeds up chemical reactions in cells.

Active Site

The specific region of an enzyme where substrate molecules bind and undergo a chemical reaction.

Substrate

The reactant molecule upon which an enzyme acts.

Competitive Inhibition

A form of enzyme inhibition where an inhibitor competes with the substrate for the active site.

Noncompetitive Inhibition

A form of enzyme inhibition where an inhibitor binds to a site other than the active site, not preventing substrate binding but inhibiting the enzyme's function.