BLG143: BIOLOGY I Chapter 8: Energy and Enzymes An Introduction to Metabolism

These flashcards cover key concepts, definitions, and processes related to energy, enzymes, and metabolism for BLG143.

Enthalpy (H)

The total energy of a thermodynamic system, including potential energy and the effect of the system on its surroundings.

Exothermic Reactions

Chemical reactions that release heat energy, resulting in a negative ΔH.

Endothermic Reactions

Chemical reactions that absorb heat energy, resulting in a positive ΔH.

Activation Energy (Ea)

The minimum energy required for a chemical reaction to occur.

Redox Reactions

Chemical reactions involving the transfer of electrons between two species.

Oxidation

The process of losing electrons during a chemical reaction.

Reduction

The process of gaining electrons during a chemical reaction.

Flavin Adenine Dinucleotide (FAD)

A coenzyme that accepts two electrons and two protons to form FADH2.

Nicotinamide Adenine Dinucleotide (NAD+)

A coenzyme that accepts two electrons and one proton to form NADH.

Adenosine Triphosphate (ATP)

The primary energy carrier in cells, providing fuel for various cellular activities.

ATP Hydrolysis

The reaction that breaks down ATP into ADP and inorganic phosphate, releasing energy.

Phosphorylation

The addition of a phosphate group to a molecule, often impacting the molecule's function.

Enzymes

Proteins that act as catalysts to accelerate chemical reactions.

Active Site

The specific region of an enzyme where substrates bind and the reaction occurs.

Induced Fit Model

The concept that enzymes change shape slightly to accommodate substrates upon binding.

Transition State

An unstable intermediate state during a chemical reaction, requiring activation energy to proceed.

Cofactors

Inorganic ions that assist enzymes in catalyzing reactions.

Coenzymes

Organic molecules that participate in enzyme-catalyzed reactions.

Prosthetic Groups

Non-amino acid molecules permanently attached to proteins, aiding in their function.

Optimal Temperature

The specific temperature at which an enzyme has maximum activity.

Optimal pH

The specific pH range at which an enzyme operates most effectively.

Competitive Inhibition

When a molecule competes with a substrate for binding to the active site of an enzyme.

Allosteric Regulation

Regulation of an enzyme by binding to a site other than the active site, altering its activity.

Covalent Modification

The chemical alteration of an enzyme's structure, affecting its function.

Feedback Inhibition

A regulatory mechanism where the end product of a metabolic pathway inhibits an early step.

Metabolic Pathway

A series of chemical reactions in a cell, each catalyzed by a specific enzyme.

Catabolic Pathways

Metabolic pathways that break down molecules to release energy.

Anabolic Pathways

Metabolic pathways that synthesize larger molecules from smaller units.

Molecular Interactions

The forces that determine reactions between molecules during enzyme activity.

Collisional Orientation

The specific alignment required for molecules to collide and react.

Kinetic Energy

The energy possessed by an object due to its motion, influencing reaction rates.

Chemical Energy

Energy stored in the bonds of chemical compounds, released during a reaction.

Potential Energy

The stored energy of a system held by its position or state.

Weak Bonds

Bonds that are easily broken and have high potential energy.

Strong Bonds

Bonds that require significant energy to break and have low potential energy.

Hydrogen Bonds

Attractive interactions that occur between molecules or within them, influencing structure.

Enzyme Specificity

The ability of an enzyme to select for a specific substrate among many potential ones.

Vmax

The maximum rate of an enzyme-catalyzed reaction when the active site is saturated.

Substrate Concentration

The amount of substrate present, affecting the rate of enzyme-catalyzed reactions.

Metabolic Intermediates

Compounds that form in the biochemical pathway between the substrate and final product.

Allosteric Site

The site on an enzyme where regulatory molecules can bind and influence activity.

Non-covalent Interactions

Transient interactions that do not involve sharing electrons, crucial for enzyme function.

Peptide Bonds

The bonds between amino acids in protein chains.

Enzyme Catalysis

The process by which an enzyme accelerates a chemical reaction.

Substrate Binding

The attachment of substrate molecules to an enzyme's active site.

Concentration Gradient

A difference in the concentration of a substance across a space.

Reaction Rate

The speed at which a chemical reaction proceeds.

Thermodynamics

The study of energy transformations in chemical processes.

Chemical Equilibrium

The state in which reactants and products are formed at the same rate.

Negative Feedback

A process that stabilizes a system by reducing the output or activity of processes.

Positive Feedback

A process that enhances and accelerates the direction of a process.

Biological Molecules

Molecules essential for life, including proteins, carbohydrates, lipids, and nucleic acids.

Electron Transport Chain

A series of protein complexes and other molecules that transfer electrons through a membrane.

Metabolic Regulation

The control of metabolic pathways to maintain homeostasis and suitable functioning.

Hydrolysis Reaction

A chemical reaction that involves the breaking down of a compound by adding water.

Cellular Respiration

The metabolic process by which cells convert biochemical energy from nutrients into ATP.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, producing ATP.

Citric Acid Cycle

A key component of cellular respiration, breaking down acetyl-CoA to produce energy.

Electron Acceptors

Molecules that receive electrons, often in redox reactions.

Conformational Change

A change in the shape of a protein that often affects its function.

Enzyme Inhibition

A process that decreases enzyme activity, slowing down biochemical reactions.

Metabolites

Small molecules that are intermediates in metabolic reactions.

Proteins

Large, complex molecules made up of amino acids that perform various functions in the body.

Catalyst

A substance that increases the rate of a reaction without being consumed.

Free Energy

The energy in a physical system that can be converted to do work.

Intramolecular Forces

Forces that hold the atoms within a molecule together.

Extramolecular Forces

Forces acting between molecules, influencing physical properties like boiling and melting points.

Enzyme Regulation

The processes that control an enzyme's activity based on the cell's needs.

Metabolism

All chemical reactions that occur within a living organism to maintain life.

Pathway Intermediates

Intermediate molecules produced during a metabolic pathway.

Biochemical Pathway

A sequence of enzymatic reactions occurring within a cell.

Metabolic Flux

The rate of turnover of metabolites within a metabolic pathway.

Chemical Stability

The tendency of a molecule to resist changes in structure or reactivity.

Environmental Factors

External conditions that affect the activity of enzymes and metabolic processes.

Covalent Bonds

Strong chemical bonds formed by the sharing of electrons between atoms.

Molecular Structure

The three-dimensional arrangement of atoms in a molecule.

Carbohydrates

Organic compounds composed of carbon, hydrogen, and oxygen, which serve as energy sources.

Lipids

Hydrophobic organic molecules including fats, oils, and hormones.

Nucleic Acids

Biopolymers essential for all known forms of life, including DNA and RNA.