Main Chemical Elements in the Body

Vocabulary flashcards covering the major, lesser, and trace chemical elements in the human body, their percentage body mass, and key functions based on the lecture slides.

Oxygen (O)

A major element making up $65.0\%$ of total body mass; part of water and many organic molecules, used to generate ATP.

Carbon (C)

A major element making up $18.5\%$ of total body mass; forms backbone chains and rings of all organic molecules.

Hydrogen (H)

A major element making up $9.5\%$ of total body mass; constituent of water and most organic molecules, whose ionized form ($H^+$) makes body fluids more acidic.

Nitrogen (N)

A major element making up $3.2\%$ of total body mass; component of all proteins and nucleic acids.

Calcium (Ca)

A lesser element making up $1.5\%$ of total body mass; contributes to bone and tooth hardness, with its ionized form ($Ca^{2+}$) needed for blood clotting, hormone release, and muscle contraction.

Phosphorus (P)

A lesser element making up $1.0\%$ of total body mass; component of nucleic acids and ATP, and required for normal bone and tooth structure.

Potassium (K)

A lesser element making up $0.35\%$ of total body mass; its ionized form ($K^+$) is the most plentiful cation in intracellular fluid and is needed to generate action potentials.

Sulfur (S)

A lesser element making up $0.25\%$ of total body mass; component of some vitamins and many proteins.

Sodium (Na)

A lesser element making up $0.2\%$ of total body mass; its ionized form ($Na^+$) is the most plentiful cation in extracellular fluid, essential for maintaining water balance and generating action potentials.

Chlorine (Cl)

A lesser element making up $0.2\%$ of total body mass; its ionized form ($Cl^-$) is the most plentiful anion in extracellular fluid and is essential for maintaining water balance.

Magnesium (Mg)

A lesser element making up $0.1\%$ of total body mass; its ionized form ($Mg^{2+}$) is needed for the action of many enzymes.

Iron (Fe)

A chemical element making up $0.005\%$ of total body mass; its ionized forms ($Fe^{2+}$ and $Fe^{3+}$) are part of hemoglobin and some enzymes.

Trace Elements

• makes up about $0.4\%$ of total body mass

• including aluminum (Al), boron (B), chromium (Cr), cobalt (Co), copper (Cu), fluorine (F), iodine (I), manganese (Mn), molybdenum (Mo), selenium (Se), silicon (Si), tin (Sn), vanadium (V), and zinc (Zn).

ATP

A molecule used by cells to temporarily store chemical energy.

Organic Molecules

Carbon-containing molecules, such as carbohydrates, lipids, proteins, and nucleic acids.

Enzymes

Molecules that increase the rate of chemical reactions in organisms.

Hemoglobin

An oxygen-carrying protein found in red blood cells.

Chemistry

The Science of Structure and interactions of matter

Matter

Anything that has mass and takes up space

Mass

The amount of matter in a object

3 Forms of Matter

• solid

• Liquid

• Gas

Elements that make up the majority of our bodies are

• oxygen

• Carbon

• Hydrogen

• Nitrogen