Anatomy & Physiology

A set of 100 vocabulary flashcards covering key chemical concepts, elements, reactions, inorganic and organic compounds, and biomolecules from the SCIE157 Introductory Chemistry lecture.

Matter

Anything that occupies space and exists in solid, liquid, or gas form, all composed of chemical elements.

Chemical Element

The simplest form of matter to have unique chemical properties; 118 are known, 26 of which are normally present in the human body.

Trace Elements

Elements present in the body in tiny amounts that play vital physiological roles.

Major Elements

The four elements—oxygen, carbon, hydrogen, and nitrogen—that constitute about $96\%$ of total body mass.

Oxygen (O)

A major element ($65.0\%$ body mass) used to generate $\text{ATP}$ and forming part of water and many organic molecules.

Carbon (C)

A major element ($18.5\%$ body mass) forming backbone chains and rings of all organic molecules.

Hydrogen (H)

A major element ($9.5\%$ body mass); constituent of water and organic molecules whose ionized form ($\text{H}^+$) makes body fluids more acidic.

Nitrogen (N)

A major element ($3.2\%$ body mass) that serves as a constituent component of all proteins and nucleic acids.

Lesser Elements

Eight chemical elements (Ca, P, K, S, Na, Cl, Mg, Fe) that account for about $3.6\%$ of total body mass.

Calcium (Ca)

Lesser element ($1.5\%$ body mass) contributing to bone/tooth hardness; ionized form ($\text{Ca}^{2+}$) needed for blood clotting, hormone release, and muscle contraction.

Phosphorus (P)

Lesser element ($1.0\%$ body mass); component of nucleic acids and $\text{ATP}$, required for normal bone and tooth structure.

Potassium (K)

Lesser element ($0.35\%$ body mass) whose ionized form ($\text{K}^+$) is the most plentiful cation in intracellular fluid, needed for action potentials.

Sodium (Na)

Lesser element ($0.2\%$ body mass) whose ionized form ($\text{Na}^+$) is the most plentiful cation in extracellular fluid, essential for maintaining water balance and action potentials.

Chlorine (Cl)

Lesser element ($0.2\%$ body mass) whose ionized form ($\text{Cl}^-$) is the most plentiful anion in extracellular fluid, essential for maintaining water balance.

Magnesium (Mg)

Lesser element ($0.1\%$ body mass) whose ionized form ($\text{Mg}^{2+}$) is needed for the action of many enzymes.

Iron (Fe)

Lesser element ($0.005\%$ body mass) whose ionized forms ($\text{Fe}^{2+}$ and $\text{Fe}^{3+}$) are part of hemoglobin and some enzymes.

Atom

The defining structure of an element, consisting of a central nucleus surrounded by circulating electrons.

Electrically Neutral Atom

An atom in which the number of positive protons equals the number of negative electrons, resulting in no net charge.

Ion

An atom that has lost or gained an electron, causing the number of protons and electrons to no longer be equal.

Anion

A negatively charged particle formed when an atom gains an electron (e.g., $\text{Cl}^-$).

Cation

A positively charged particle formed when an atom loses an electron (e.g., $\text{Ca}^{2+}$).

Electrolytes

Substances (acids, bases, or salts) that ionize in water, playing essential roles in chemical reactivity, osmotic effects, and electrical balance.

Molecule

A structure formed when two or more atoms become united by a chemical bond through the sharing of electrons.

Compound

A molecule containing atoms derived from two or more different chemical elements (e.g., $\text{CO}_2$).

Chemical Bonds

Forces that unite atoms based on electron sharing, donating, or acquiring; the three main physiological types are ionic, covalent, and hydrogen bonds.

Metabolism

The sum total of all chemical reactions occurring within the body.

Law of Conservation of Mass

Principle stating that mass is neither created nor destroyed during chemical reactions.

Energy

The capacity to do work.

Potential Energy

Energy contained in matter due to its position or state, which is not actively doing work.

Chemical Energy

A form of potential energy stored within the chemical bonds of compounds and molecules.

Kinetic Energy

Energy associated with matter in motion, actively doing work.

Law of Conservation of Energy

Principle stating that energy can neither be created nor destroyed, only converted from one form to another.

Endergonic Reaction

A chemical reaction that absorbs more energy than it releases.

Exergonic Reaction

A chemical reaction that releases more energy than it absorbs.

Activation Energy

The initial energy required to start a chemical reaction.

Catalysts

Substances that accelerate chemical reactions by lowering activation energy without being consumed; enzymes are the most important biological catalysts.

Synthesis Reaction

A chemical reaction in which two or more atoms, ions, or molecules combine to form new and larger molecules.

Anabolism

The sum of all synthesis reactions in the body; energy-storing (endergonic) processes that form new bonds to build larger molecules.

Decomposition Reaction

A chemical reaction in which large molecules are split into smaller atoms, ions, or molecules.

Catabolism

The sum of all decomposition reactions in the body; energy-releasing (exergonic) processes that break covalent bonds.

Exchange Reaction

A reaction consisting of both synthesis and decomposition steps, represented as $\text{AB} + \text{CD} \rightarrow \text{AC} + \text{BD}$.

Reversible Reaction

A chemical reaction that can proceed in either direction depending on reactant and product concentration.

Chemical Equilibrium

A dynamic state in a reversible reaction where the forward and reverse reaction rates balance.

Oxidation-Reduction Reaction

Essential physiological reactions (redox) in which electrons are transferred between atoms or molecules.

Oxidation

The loss of electrons from a substance, resulting in a release of stored energy.

Reduction

The gain of electrons by a substance, resulting in a gain of stored energy.

Inorganic Compounds

Structurally simple compounds that usually lack carbon, including water, acids, bases, and salts.

Organic Compounds

Compounds that ALWAYS contain carbon (and usually hydrogen), capable of forming large complex structures.

Intracellular Fluid (ICF)

Fluid inside body cells, accounting for $65\%$ of total body water.

Extracellular Fluid (ECF)

Fluid outside body cells, accounting for $35\%$ of total body water.

Polarity of Water

Property caused by partial negative charge near oxygen and partial positive charge near hydrogens, giving water life-supporting properties.

Properties of Water Supporting Life

Five key life-supporting features of water: solvency, adhesion, cohesion, chemical reactivity, and thermal stability.

Major Intracellular Ions

The primary ions dissolved within intracellular fluid, specifically $\text{K}^+$ and phosphates.

Major Extracellular Ions

The primary ions dissolved in extracellular fluid: $\text{Na}^+$, $\text{Ca}^{2+}$, $\text{Cl}^-$, and bicarbonate.

Mixture

A combination of elements or compounds physically blended together but not chemically bonded.

Inorganic Acid

A substance that dissociates into hydrogen ions ($\text{H}^+$) and one or more anions in water.

Inorganic Base

A substance that dissociates into hydroxide ions ($\text{OH}^-$) and one or more cations in water.

Inorganic Salt

A substance that dissociates into cations and anions in water, neither of which is $\text{H}^+$ or $\text{OH}^-$.

Monomers

Identical or similar small molecular subunits that serve as building blocks for polymers.

Polymers

Large molecules constructed by combining many repeating monomer subunits via polymerization.

Macromolecules

Very large organic molecules composed of joined monomers, such as starch, proteins, and DNA.

Dehydration Synthesis

A chemical reaction where monomers bond to produce a polymer, releasing a water molecule as a byproduct.

Hydrolysis

A chemical reaction in which water is used to break down a polymer into individual monomers.

Carbohydrates

Organic molecules providing a quickly mobilized energy source; all digested carbohydrates convert to glucose to form $\text{ATP}$.

Monosaccharides

Simple sugars containing from $3$ to $7$ carbon atoms, including glucose, fructose, galactose, deoxyribose, and ribose.

Disaccharides

Simple sugars formed by joining two monosaccharides through dehydration synthesis (e.g., sucrose, lactose, maltose).

Polysaccharides

Complex carbohydrates formed from tens to hundreds of monosaccharides joined by dehydration synthesis.

Glucose

The primary "blood sugar" used by cells to produce $\text{ATP}$.

Fructose

A monosaccharide simple sugar found in fruits.

Galactose

A monosaccharide simple sugar found as a component of milk sugar.

Deoxyribose

A monosaccharide sugar that is a structural component of DNA.

Ribose

A monosaccharide sugar that is a structural component of RNA.

Sucrose

A disaccharide (table sugar) composed of glucose + fructose.

Lactose

A disaccharide (milk sugar) composed of glucose + galactose.

Maltose

A disaccharide composed of two glucose molecules.

Glycogen

The stored polysaccharide form of carbohydrates in animals, synthesized after meals and broken down between meals.

Starch

A plant storage polysaccharide of about $3{,}000$ glucose monomers and the main carbohydrate in human food.

Cellulose

Plant cell wall polysaccharide that humans cannot digest; the most abundant organic compound on Earth and an important dietary fibre.

Water-Soluble Fibre

Dietary fibre that reduces blood cholesterol levels by lowering low-density lipoproteins (LDL).

Water-Insoluble Fibre

Dietary fibre that absorbs water and swells, softening stool, increasing bulk, and reducing transit time in the colon.

Lipids

Hydrophobic organic molecules carrying more calories per gram than carbohydrates; function primarily in energy storage, insulation, and protection.

Fatty Acids

Molecules used to synthesize triglycerides and phospholipids or catabolized to generate $\text{ATP}$.

Saturated Fats

Fatty acids loaded with as much hydrogen as possible, containing no carbon-carbon double bonds.

Essential Fatty Acids

Fatty acids that cannot be synthesized by the human body and must be obtained through dietary sources.

Triglycerides

The most plentiful lipids in the body and diet, composed of three fatty acids and a glycerol.

Phospholipids

Lipids with two hydrophobic fatty acid tails and a hydrophilic phosphate head, serving as the structural foundation of cell membranes.

Cholesterol

Parent steroid required for cell membrane structure; precursor to bile salts, vitamin D, and steroid hormones ($85\%$ produced by body, $15\%$ from diet).

Low-Density Lipoprotein (LDL)

Lipoprotein known as "bad" cholesterol that transports lipids in blood and contributes to cardiovascular disease.

High-Density Lipoprotein (HDL)

Lipoprotein known as "good" cholesterol that removes excess cholesterol from blood to protect against cardiovascular disease.

Eicosanoids

Lipid molecules (prostaglandins and leukotrienes) that modify hormone responses, blood clotting, inflammation, immunity, and smooth muscle contraction.

Carotenes

Lipids needed for the synthesis of vitamin A (used for visual pigments in the eye) and functioning as antioxidants.

Vitamin D

A steroid lipid that helps regulate calcium levels in the body for bone growth and repair.

Vitamin E

A lipid that promotes wound healing, prevents tissue scarring, supports nervous system structure/function, and acts as an antioxidant.

Vitamin K

A lipid required for the synthesis of blood-clotting proteins.

Proteins

The most versatile body molecules; polymers of amino acids linked together by peptide bonds.

Amino Acids

Monomer units of proteins; $20$ are biologically important to humans ($8$ essential, $12$ non-essential).

Complete Proteins

Dietary protein sources containing adequate amounts of all essential amino acids (e.g., meat, fish, poultry, eggs, milk).

Protein Conformation

The unique, three-dimensional shape of a protein that is crucial to its biological function.

Protein Denaturation

An extreme conformational change in a protein caused by heat or extreme pH that destroys its biological function.

Primary Structure of Protein

The unique linear sequence of amino acids linked together by peptide bonds in a polypeptide chain.