BIO 1100 – Chemistry of Life

Vocabulary flashcards covering key terms from the BIO 1100 ‘Chemistry of Life’ lecture notes.

Atom

Smallest unit of an element that retains the element’s properties.

Proton

Positively charged sub-atomic particle located in the atomic nucleus.

Neutron

Neutral sub-atomic particle found in the atomic nucleus.

Electron

Negatively charged sub-atomic particle that orbits the nucleus.

Matter

Anything that occupies space and has mass.

Element

Substance that cannot be broken down by chemical reactions into other substances.

Compound

Substance composed of two or more elements in a fixed ratio.

Macronutrient

Essential element required in large amounts, e.g., C, O, H, N, P, K.

Micronutrient

Essential element needed only in trace amounts, e.g., Zn, Cu, Fe.

Valence Electron

Outer-shell electron involved in chemical bonding.

Electronegativity

Tendency of an atom to attract shared electrons toward itself.

Covalent Bond

Chemical bond formed by sharing pairs of valence electrons.

Non-polar Covalent Bond

Covalent bond with equal sharing of electrons between atoms.

Polar Covalent Bond

Covalent bond with unequal electron sharing, producing partial charges.

Ionic Bond

Electrostatic attraction between oppositely charged ions after electron transfer.

Cation

Positively charged ion formed by electron loss.

Anion

Negatively charged ion formed by electron gain.

Hydrogen Bond

Weak attraction between a partially positive hydrogen and an electronegative atom (O or N).

Cohesion

Attraction between like molecules; in water due to hydrogen bonding.

Adhesion

Clinging of one substance to a different substance.

Transpiration

Upward movement of water in xylem and its evaporation from plant stomata.

Surface Tension

Measure of how difficult it is to break the surface of a liquid.

Specific Heat

Heat required to raise or lower temperature of 1 g of a substance by 1 °C.

Evaporative Cooling

Cooling that occurs as the hottest water molecules evaporate (e.g., sweating).

Solute

Substance that is dissolved in a solution.

Solvent

Substance that dissolves a solute; water is the universal solvent.

Solution

Homogeneous mixture of solute and solvent.

Hydrophilic

Having an affinity for water; water-soluble.

Hydrophobic

Water-repelling; does not dissolve in water.

Monomer

Small building-block molecule of a polymer.

Polymer

Long chain molecule made of repeating monomers.

Condensation or dehydration

Joins two monomers by removing a molecule of water.

Hydrolysis

Breaks polymers into monomers by adding water.

Carbohydrate

Organic molecule of C, H, and O in ~1:2:1 ratio; sugars and starches.

Monosaccharide

Simple sugar; carbohydrate monomer (e.g., glucose).

Disaccharide

Sugar composed of two monosaccharides (e.g., sucrose).

Polysaccharide

Polymer of many monosaccharides (e.g., starch, cellulose).

Starch

Plant storage polysaccharide of glucose (amylose & amylopectin).

Glycogen

Animal storage polysaccharide of glucose.

Cellulose

Structural polysaccharide in plant cell walls.

Chitin

Structural polysaccharide in arthropod exoskeletons and fungal walls.

Lipid

Hydrophobic biomolecule of mostly C and H; not a true polymer.

Triglyceride

Lipid of glycerol plus three fatty acids linked by ester bonds.

Saturated Fatty Acid

Fatty acid with no C=C double bonds; solid at room temperature.

Unsaturated Fatty Acid

Fatty acid with one or more C=C double bonds; liquid at room temperature.

Phospholipid

Lipid with glycerol, two fatty acids, and phosphate; forms cell membranes.

Steroid

Lipid with four fused rings; includes cholesterol and hormones.

Cholesterol

Steroid component of cell membranes and hormone precursor.

Protein

Polymer of amino acids that performs diverse cellular functions.

Amino Acid

Monomer with amino group, carboxyl group, hydrogen, and variable R-group.

Peptide Bond

Covalent bond linking amino acids via dehydration synthesis.

Chaperonin

Protein that assists the proper folding of other proteins.

Enzyme

Protein catalyst that speeds reactions without being consumed.

Substrate

Reactant upon which an enzyme acts.

Nucleic Acid

Polymer of nucleotides; DNA or RNA.

Nucleotide

Monomer of nucleic acids: nitrogenous base, pentose sugar, phosphate.

Phosphodiester Bond

Covalent bond between sugar and phosphate in nucleic acid backbone.

DNA

Double-stranded helical nucleic acid storing hereditary information (A,T,C,G).

RNA

Single-stranded nucleic acid involved in gene expression (A,U,C,G).

Pyrimidine

Single-ring nitrogenous base: cytosine, thymine, uracil.

Purine

Double-ring nitrogenous base: adenine, guanine.

James Watson and Francis Crick

1953 double-helix structure of DNA was proposed by

Rosalind Franklin

Scientist whose X-ray diffraction images revealed DNA’s helical structure.