Biology Chapter on Metabolic Processes

Metabolic Processes and Enzymes

• Feedback Inhibition: A metabolic pathway is shut down when its end product accumulates.
• Chemical Resources: Organisms regulate the synthesis of products to prevent waste.
• Cooperativity: Enzyme activity is amplified by substrate binding.
• Allosteric Regulation: A regulatory molecule alters protein function at a different site.
• Active Enzyme Form: Stabilized by an activator binding.
• Inactive Enzyme Form: Stabilized by an inhibitor binding.
• Metabolism: The sum of all chemical reactions in an organism.
• Catabolic Pathways: Break down complex molecules to release energy.
• Anabolic Pathways: Use energy to build complex molecules.
• Bioenergetics: The study of energy flow in organisms.

Energy and Thermodynamics

• Kinetic Energy: Energy of motion.
• Potential Energy: Energy due to position or structure.
• Chemical Energy: Potential energy in chemical bonds.
• Thermodynamics: The study of energy transformations.
• Open System: Exchanges matter and energy with surroundings.
• Closed System: Does not exchange matter with surroundings.
• First Law of Thermodynamics: Energy cannot be created or destroyed.
• Second Law of Thermodynamics: Energy transformations increase entropy (disorder) in the universe.
• Entropy: A measure of disorder in a system.
• Spontaneous Processes: Occur without energy input, increase entropy.
• Ordered Structures: Living organisms create order from less ordered materials using energy.
• Energy Flow in Ecosystems: Enters as light, exits as heat.
• Bioluminescence: Conversion of chemical energy to light.
• Chemical Chaos: Result of unregulated metabolic pathways.
• Exergonic Reaction: Releases energy, is spontaneous.
• Endergonic Reaction: Absorbs energy, is non-spontaneous.
• Equilibrium: State where reactions do no further work.

ATP and Enzyme Function

• ATP: Adenosine triphosphate; the cell's energy currency.
• ADP: Adenosine diphosphate; a product of ATP hydrolysis.
• ATP Hydrolysis: The breaking of phosphate bonds, releasing energy.
• Phosphate Groups: Three phosphate groups in ATP store energy.
• Chemical Work: Involves making or breaking chemical bonds.
• Transport Work: Movement of substances across membranes.
• Mechanical Work: Movement of structures within cells.
• Catalyst: Substance that speeds up a chemical reaction.
• Enzyme: A protein that acts as a catalyst.
• Sucrase: Enzyme that breaks down sucrose.
• ATP Cycle: Continuous regeneration of ATP from ADP.
• Free Energy: Energy available to do work in a system.
• ΔG: Change in free energy; indicates reaction spontaneity.
• Metabolic Reactions: Chemical reactions maintaining life processes.
• Sucrose: A disaccharide made of glucose and fructose.
• Glucose/Fructose: Monosaccharides with formula C₆H₁₂O₆.
• Activation Energy (EA): Energy needed to start a chemical reaction.
• Transition State: Temporary, high-energy state during a chemical reaction.
• Enzyme-Substrate Complex: Temporary complex formed when enzyme binds substrate.
• Induced Fit: Enzyme changes shape to fit substrate.
• Catalysis: Process of accelerating a chemical reaction.
• Cofactors: Non-protein helpers that assist enzyme function.
• Coenzymes: Organic cofactors, often vitamins.
• Competitive Inhibitors: Compete with substrate for the active site.
• Noncompetitive Inhibitors: Bind elsewhere, changing enzyme shape and function.
• Optimal Temperature: Temperature where enzyme activity is maximum.

Enzyme Activity

• Optimal pH: pH level where enzymatic activity is maximum.
• Thermal Energy: Energy from heat that provides activation energy.
• Chemical Groups: Specific functional groups that enhance reaction catalysis.
• Environmental Factors: Conditions like temperature and pH that influence enzyme activity.