Molecules of Life

Martinus Beijerinck

A microbiologist from the Netherlands in the Golden Age who isolated nitrogen-fixing microorganisms called rhizobia.

Rhizobia

Nitrogen-fixing microorganisms isolated from the root nodules of legumes, helping to enrich soil.

Isotope

Variants of elements that have different numbers of neutrons.

Mass Number

The sum of protons and neutrons in an atom.

Valence Electrons

Electrons in the outer shell of an atom that determine its chemical bonds.

Chemical Bonds

Forces that hold atoms together; includes ionic, covalent, and hydrogen bonds.

Ionic Bonds

Formed through the transfer of electrons, resulting in attraction between positively and negatively charged ions.

Covalent Bonds

Form when atoms share electrons, resulting in molecules.

Hydrogen Bonds

Weak attractions between hydrogen atoms in polar molecules and electronegative atoms.

pH Scale

A measure of the acidity or basicity of a solution, where 7 is neutral.

Buffers

Chemicals that stabilize pH levels in a solution.

Monosaccharides

The simplest carbohydrates, serving as building blocks for more complex carbohydrates.

Polysaccharides

Chains of monosaccharides that serve various functions, including energy storage and structural roles.

Triglycerides

Common simple lipids composed of three fatty acids and glycerol.

Amino Acids

Building blocks of proteins, consisting of a central carbon, amino group, carboxyl group, and R group.

Proteins

Biological molecules essential for countless functions in cells, including structural and enzymatic roles.

Nucleotides

Subunits of nucleic acids composed of a pentose sugar, phosphate group, and nucleobase.

DNA

Deoxyribonucleic acid, the genetic material consisting of two strands forming a double helix.

RNA

Ribonucleic acid, a single-stranded molecule involved in protein synthesis.