Biology 110: Test-2 Potential Questions and Essays

Comprehensive vocabulary flashcards covering the core principles of metabolism, cellular respiration, and photosynthesis detailed in the Biology 110 Test-2 study guide.

Potential and Kinetic Energy

Two fundamental forms of energy that differ in their chemical and cellular manifestations, such as stored chemical energy versus energy of motion.

First Law of Thermodynamics

A fundamental law of thermodynamics stating that energy cannot be created or destroyed, which applies directly to how living organisms transform energy.

Second Law of Thermodynamics

A law of thermodynamics establishing that every energy transfer increases the entropy of the universe, dictating how living organisms maintain order and release heat.

Coupled Reaction

A linked pair of biochemical reactions in metabolism where an exergonic (energy-releasing) reaction directly powers an endergonic (energy-requiring) reaction.

Enzyme Structure and Function

The relationship wherein an enzyme's specific three-dimensional conformation and active site shape determine its catalytic activity and substrate specificity.

Competitive Inhibition

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

Noncompetitive Inhibition

A mechanism of enzyme inhibition where an inhibitor binds to a location other than the active site, altering the enzyme's structure and reducing its function.

Allosteric Site

A specific receptor site on an enzyme distinct from the active site where regulatory molecules bind to activate or inhibit enzyme functioning.

Energy of Activation

The initial amount of energy required to start a chemical reaction, which an enzyme accelerates by lowering this threshold.

Redox Reaction

An oxidation-reduction reaction in which electrons are transferred between chemical species, fundamental to cellular energy extraction.

Electron Carriers

Specialized organic molecules used by biological systems to transport high-energy electrons between metabolic pathways.

Aerobic and Anaerobic Pathways

Two cellular pathways used to extract energy from organic molecules, distinguished by their mechanism of ATP formation, their final electron acceptor, and their end products.

Glycolysis

A primary metabolic pathway of cellular respiration occurring in the cytoplasm that breaks down glucose into pyruvate, evaluated by its inputs, outputs, fate of carbons, and energy transfer.

Formation of Acetyl CoA

The intermediate step in cellular respiration that converts pyruvate into acetyl CoA, analyzed by its inputs, outputs, fate of carbons, energy transfer, and cellular location.

Citric Acid Cycle (aka Krebs Cycle)

A major cyclical pathway of cellular respiration that oxidizes acetyl groups to produce carbon dioxide, ATP, NADH, and $FADH_2$.

Electron Transport & Chemiosmosis

The final stage of cellular respiration where electron transfers drive a proton gradient across a membrane to synthesize the bulk of cellular ATP.

Mitochondria

The cellular organelles where specific stages of cellular respiration (acetyl CoA formation, the Krebs cycle, and electron transport/chemiosmosis) occur to generate ATP, NADH, and $FADH_2$.

RuBP Regeneration

The stage of the Calvin cycle in which energy from ATP is utilized to convert RP back into RuBP.

RuBP

A five-carbon sugar molecule essential to the Calvin cycle that accepts carbon dioxide and is regenerated from RP using ATP.

RP

The intermediate precursor molecule in the Calvin cycle that is converted back into RuBP using energy from ATP.

Calvin Cycle

The light-independent reactions of photosynthesis in which carbon fixation occurs and RuBP is continuously regenerated from RP using energy from ATP.

Photosystem I and Photosystem II

Two distinct light-absorbing protein complexes in the thylakoid membrane that perform complementary roles in light reactions, electron excitation, and ATP/NADPH production.

Phosphorylation

The biochemical addition of a phosphate group to an organic molecule, such as the synthesis of ATP from ADP and inorganic phosphate during photosynthesis and respiration.