Anatomy and Physiology: Chemical Reactions, Homeostasis, and Atomic Structure

Vocabulary flashcards reviewing cellular chemical reactions, metabolic processes, aqueous solutions, pH balance, homeostatic regulation, and atomic structure based on lecture transcript notes.

Reactants

The starting reacting substances whose atoms are rearranged during a chemical reaction.

Products

The different substances formed as a result of a chemical reaction.

Metabolism

All the chemical reactions occurring in the body at any given moment.

Work

The movement of an object or a change in the physical structure of matter.

Energy

The capacity to do work.

Kinetic Energy

Energy in motion or energy that is released during physical movement.

Potential Energy

Stored energy capable of doing work in the future.

Metabolite

A waste product or byproduct generated during metabolic reactions.

Decomposition Reaction

A reaction that breaks down a molecule into smaller components, represented as $AB \rightarrow A + B$.

Catabolism

The metabolic breakdown of complex molecules in the body through decomposition reactions.

Hydrolysis

A water-loosening reaction that breaks apart molecules in the presence of water.

Anabolism

The metabolic process of building complex structures from simpler components.

Dehydration Synthesis

A synthesis reaction that joins molecules together by removing water.

Exchange Reaction

A chemical reaction where reactant components swap partners, such as $AB + CD \rightarrow AD + CB$.

Reversible Reaction

A chemical reaction capable of proceeding in either direction to release or absorb energy.

Enzymes

Proteins that catalyze reactions and speed up metabolic processes by lowering activation energy.

Activation Energy

The amount of energy required to initiate a chemical reaction.

Exergonic Reaction

A reaction that releases energy to its surroundings.

Endergonic Reaction

A reaction that absorbs or requires energy input to proceed.

Nutrients

Essential substances obtained from food that are necessary for normal physiological function.

Organic Molecule

A chemical compound that must contain at least one carbon-hydrogen bond.

Inorganic Molecule

A chemical compound lacking carbon-hydrogen bonds, such as $CO_2$, oxygen, water, acids, bases, and salts.

Solution

A homogeneous mixture created by combining a liquid solvent with solute particles.

Solvent

The liquid medium in a solution used to dissolve, absorb, or dissociate solute particles.

Solutes

Particles dissolved or dispersed within a solvent.

Heat Capacity

The quantity of heat required to raise the temperature of a unit mass of a substance by $1^{\text{o}}\text{C}$.

Thermal Inertia

The tendency of a large body of water to resist rapid temperature changes due to its high heat capacity.

Hydrophilic

Molecules that dissolve readily in water due to polar attraction ("water-loving").

Hydrophobic

Molecules that do not mix with or dissolve in water ("water-fearing").

Colloid

A stable mixture containing dispersed particles that remain permanently in solution without settling out.

Suspension

A mixture containing large particles that will settle out of solution over time if left standing.

pH

A logarithmic measurement representing the percent concentration of hydrogen ions in a solution.

Acid

A hydrogen ion or proton donor that releases acidic hydrogen ions ($H^+$) in solution.

Base

A proton acceptor that releases hydroxide ions ($OH^-$) or removes hydrogen ions from solution.

Buffers

Compounds that stabilize solution pH by removing or replacing excess hydrogen ions.

Homeostasis

The state of dynamic equilibrium maintaining a stable internal physiological environment around a set point.

Auto Regulation

An automatic local adjustment made by a cell, tissue, or organ in response to environmental change.

Extrinsic Regulation

Homeostatic regulation controlled externally by the activities of the nervous system or endocrine system.

Receptor

A sensory mechanism that monitors environmental conditions and detects deviations from homeostatic set points.

Control Center

An integration center that processes signals from receptors and sends commands to effectors.

Effector

A cell, tissue, or organ that responds to control center commands to oppose or enhance a stimulus.

Negative Feedback

A regulatory mechanism where the body's response counteracts deviation and returns conditions to a set point.

Positive Feedback

A regulatory mechanism that exaggerates or intensifies an original stimulus condition.

Atomic Number

The number of protons in an atom's nucleus.

Mass Number

The total weight of an atom, determined by adding the number of protons and neutrons.

Isotope

A structural variation of an element formed when the number of neutrons in the nucleus changes.

Valence Electrons

Electrons occupying the outermost electron shell of an atom.

Cation

A positively charged ion produced when an atom loses one or more electrons.

Anion

A negatively charged ion produced when an atom gains one or more electrons.

Ionic Bond

A chemical bond created by the electrostatic attraction between oppositely charged cations and anions.

Covalent Bond

A strong chemical bond formed when atoms share valence electrons.

Hydrogen Bond

A weak polar attraction between partial positive hydrogen charges and partial negative molecular regions.