BIO NMDCAT

The Induced Fit model states the active site is not rigid; substrate binding induces a conformational change that properly positions catalytic groups for optimized catalysis.

At high substrate concentrations, all enzyme active sites are occupied. The reaction velocity reaches a maximum (Vmax), and further substrate addition cannot increase the rate.

Km is a measure of an enzyme's affinity for its substrate, defined as the substrate concentration at which the reaction rate is one-half of the maximum velocity (Vmax).

Enzymes are biological catalysts that accelerate reactions by decreasing the activation energy. They do not provide energy, alter the equilibrium constant, or change the free energy change (ΔG) of the overall reaction.

The tertiary structure of an enzyme, which dictates the shape of the active site, is stabilized by hydrogen bonds, ionic interactions, hydrophobic interactions, van der Waals forces, and covalent disulfide bonds.

A prosthetic group is a non-protein unit that is covalently or very tightly bound to an apoenzyme, making it a permanent part of the functional holoenzyme.

The active site is a specific, flexible 3D pocket formed by a few amino acids that binds the substrate and catalyzes its conversion to product via weak interactions.

Enzymes lower activation energy by providing an alternative reaction pathway where specific R-groups orient and stress substrates, stabilizing the transition state.

Peripheral proteins sit on the outside (or inside) surface of the bilayer.

Both facilitated and simple diffusion are passive processes driven by concentration gradients.

Cholesterol is a steroid, characterized by its four-ring hydrocarbon structure.

Immune cells use recognition markers to identify infected or foreign cells (e.g., pathogens).

Its ability to regulate its own composition and environment is a fundamental property of a living membrane.

Pinocytosis is a type of endocytosis where the membrane invaginates to take in fluid.

The cell membrane's surface markers are crucial for identifying "self" vs "non-self" cells.

Saturated chains pack tightly, resulting in a more rigid, less fluid membrane.

The phosphate group is negatively charged and highly attracted to water.

Carrier proteins bind specific molecules and shift conformation to move them across the membrane.

It is passive (no ATP) but uses a protein facilitator.