Prototype for Bio Review Cards

What is the effect of a competitive inhibitor on enzyme kinetics?

It binds directly to the active site, competing with the substrate. It increases Km (lowers affinity) but Vmax can still be reached at high substrate concentrations.

What is the effect of a non-competitive (allosteric) inhibitor on enzyme kinetics?

It binds to an allosteric site (away from active site), changing enzyme conformation. It lowers Vmax and cannot be overcome by adding more substrate.

What occurs to a plant cell placed in a hypotonic solution vs a hypertonic solution?

Hypotonic: Water enters, cell becomes turgid (normal/healthy state). Hypertonic: Water leaves, causing plasmolysis (plasma membrane pulls away from cell wall).

What occurs to an animal cell placed in a hypotonic vs hypertonic solution?

Hypotonic: Water enters, causing the cell to swell and potentially lyse (burst). Hypertonic: Water leaves, causing the cell to crenate (shrivel).

Primary vs Secondary Active Transport

Primary uses ATP directly (e.g., Na+/K+ pump). Secondary uses the electrochemical gradient created by primary transport to move another solute against its gradient (e.g., Na+/Glucose cotransporter).

Inputs and Outputs of Glycolysis

Location: Cytoplasm. Inputs: 1 Glucose, 2 NAD+, 2 ATP. Net Outputs: 2 Pyruvate, 2 NADH, 2 Net ATP (via substrate-level phosphorylation).

Inputs and Outputs of Pyruvate Oxidation

Location: Mitochondrial Matrix. Inputs: 2 Pyruvate, 2 NAD+, 2 CoA. Outputs: 2 Acetyl-CoA, 2 NADH, 2 CO2.

Inputs and Outputs of the Citric Acid (Krebs) Cycle (per Glucose)

Location: Mitochondrial Matrix. Inputs: 2 Acetyl-CoA. Outputs (2 turns): 6 NADH, 2 FADH2, 2 ATP, 4 CO2.

Role of Oxygen in Cellular Respiration

Acts as the final electron acceptor at the end of the Electron Transport Chain (ETC), combining with electrons and H+ to form H2O.

Mechanism of Chemiosmosis in ATP Synthesis

ETC pumps protons (H+) into the intermembrane space creating a proton-motive force. Protons flow back into the matrix through ATP Synthase, driving ATP phosphorylation.

How do Lactic Acid Fermentation and Alcohol Fermentation regenerate NAD+?

In the absence of O2, NADH transfers its electrons to pyruvate (forming lactate) or acetaldehyde (forming ethanol + CO2), regenerating NAD+ so glycolysis can continue.

Light-Dependent Reactions vs Calvin Cycle in Photosynthesis

Light-Dependent (Thylakoids): Uses H2O and light to produce O2, ATP, and NADPH. Calvin Cycle (Stroma): Uses CO2, ATP, and NADPH to synthesize G3P (precursor to glucose).