Unit 3 Study Guide: Enzymes and Photosynthesis

Enzyme

Protein that catalyzes biochemical reactions.

Active Site

Region on enzyme where substrates bind.

Induced Fit

Enzyme changes shape to better fit substrate.

Activation Energy

Energy required to start a chemical reaction.

Denaturation

Loss of enzyme structure due to extreme conditions.

Competitive Inhibitor

Binds to active site, blocking substrate access.

Noncompetitive Inhibitor

Binds elsewhere, changing enzyme shape and function.

Saturation Point

Maximum rate of reaction when all enzymes are occupied.

Photosynthesis

Process converting light energy into chemical energy.

Autotrophs

Organisms that produce their own food.

Heterotrophs

Organisms that consume others for food.

Light Dependent Reactions

Convert light energy into ATP and NADPH.

Calvin Cycle

Uses ATP and NADPH to fix carbon dioxide.

Chloroplast

Organelle where photosynthesis occurs.

NADPH

Primary electron carrier in photosynthesis.

Thylakoid Membranes

Site of light dependent reactions in chloroplasts.

Stroma

Fluid where the Calvin Cycle occurs.

Redox Process

Involves oxidation and reduction reactions.

Carotenoids

Pigments that absorb red, yellow, and orange light.

G3P

Product of Calvin Cycle, used for energy.

Enzyme Function Factors

Temperature, pH, and chemicals affect enzyme activity.

Hydrolysis of Sucrose

Conversion process sped up by enzymes.

Cyanide

Irreversible inhibitor that blocks enzyme function.

Entropy

Measure of disorder; increases with certain products.

Photosystem I

Complex involved in light reactions of photosynthesis.

Photosystem II

Complex that splits water in light reactions.

Thylakoid Membrane

Site of electron transport in photosynthesis.

Cyclic Electron Flow

Occurs at photosystem I, produces ATP only.

Rubisco

Enzyme catalyzing carbon fixation in plants.

Carbon Fixation

First step in Calvin Cycle, incorporates CO2.

Calvin Cycle Phases

Includes carbon fixation, reduction, regeneration.

Photorespiration

Occurs when O2 binds rubisco, reducing output.

Cellular Respiration Equation

C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O.

Energy Investment Stage

Uses ATP to phosphorylate glucose initially.

Substrate Level Phosphorylation

ATP synthesis during glycolysis and citric acid cycle.

Acetyl CoA

Product of pyruvate oxidation entering citric acid cycle.

Citric Acid Cycle

Converts Acetyl CoA into citrate, releases CO2.

Lactic Acid Fermentation

Occurs in muscle cells when oxygen is depleted.

Electron Transport Chain (ETC)

Final stage of cellular respiration, produces ATP.

Oxidative Phosphorylation

Generates 26-28 ATP via H+ gradient.

Anaerobic Respiration ATP Yield

Only 2 ATP produced per glucose molecule.

Golgi Complex

Modifies and packages proteins for transport.

Oxygen's Role in Respiration

Final electron acceptor in the ETC.

Highlander Deer Mice Adaptation

Genetic trait improves oxygen binding at high altitudes.

Adaptations

Traits developed through random genetic mutations.

Phenotype

Observable characteristics resulting from genetic expression.

ATP Synthase

Enzyme that synthesizes ATP using H+ gradient.

Fats vs. Carbohydrates

Fats store more energy due to carbon chains.

NADH

Electron carrier reduced from NAD+ during respiration.

Glycolysis

First step of cellular respiration, occurs in cytoplasm.

Chemiosmosis

Process powering ATP synthesis via H+ gradient.