Bioenergetics and Cellular Processes

These flashcards cover key vocabulary and concepts related to bioenergetics, cellular respiration, and photosynthesis, facilitating effective study and understanding for the exam.

Bioenergetics

The study of how cells accomplish energy transformations and processes.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transferred.

Second Law of Thermodynamics

Energy transfer leads to increased disorder, or entropy.

Exergonic Reactions

Reactions where products have less energy than reactants.

Endergonic Reactions

Reactions requiring an input of energy, resulting in products with higher energy.

Enzymes

Biological catalysts that speed up reactions by lowering activation energy.

Enzyme Specificity

The concept that each enzyme catalyzes only one type of reaction.

Active Site

The region on an enzyme where substrates bind to form an enzyme-substrate complex.

Induced-fit Model

The model explaining how enzymes change shape to fit substrates during a reaction.

Cofactors

Supporting factors that assist enzymes, which can be either organic (coenzymes) or inorganic.

Competitive Inhibition

When an inhibitor competes with the substrate for binding to the active site.

Noncompetitive Inhibition

When an inhibitor binds to an allosteric site, distorting the enzyme's shape and function.

ATP (Adenosine Triphosphate)

The primary energy carrier in cellular processes, made of adenosine and three phosphates.

Photosynthesis

• Location: Chloroplasts (Thylakoid for light reactions, stroma for Calvin cycle)

• Reactants: CO₂, H₂O, light energy

• Products: Glucose (C₆H₁₂O₆), O₂

Light Reactions

The initial phase of photosynthesis that converts sunlight into ATP and NADPH.

Calvin-Benson Cycle

The dark reactions of photosynthesis that convert CO2 and energy into glucose.

Glycolysis

• Location: Cytoplasm

• Reactants: Glucose, 2 NAD⁺, 2 ADP + 2 Pi

• Products: 2 Pyruvate, 2 NADH, 2 ATP (net)

Krebs Cycle

• Location: Mitochondrial matrix

• Reactants: 2 Acetyl-CoA, 6 NAD⁺, 2 FAD, 2 ADP + 2 Pi

• Products: 4 CO₂, 6 NADH, 2 FADH₂, 2 ATP

Electron Transport Chain (ETC)

A sequence of proteins that transfers electrons during cellular respiration, producing ATP. Happens in the inner mitochondrial membrane.

Chemiosmosis

The process where hydrogen ions diffuse back through ATP synthase to produce ATP.

Fermentation

An anaerobic process that allows glycolysis to continue by converting pyruvate to lactic acid or ethanol.

oxidative phosphorylation

• Location: Inner mitochondrial membrane

• Reactants: NADH, FADH₂, O₂, ADP + Pi

• Products: NAD⁺, FAD, H₂O, ~32–34 ATP