Chemistry for Biology 

Molecules- a physical unit made up of one or more atoms held together by strong bonds.

Atoms- basic building blocks of life that combine to make molecules

Hydrophilic interaction- water loving interactions usually associated with polar molecules.

Hydrophobic interaction- water fearing interactions associated with non-polar molecules.

Biological molecules- the 4 basic molecules that are essential to life (i.e. carbohydrates, lipids, proteins, and nucleic acids).

Covalent bonds- bonds formed between atoms that involve sharing of electrons.

Ionic bonds- bonds formed between atoms that involve donating or accepting electrons.

Polar covalent bonds- covalent bonds between atoms when electronegativity differences are below 1.5. This is usually a result of unequal sharing of electrons.

Nonpolar covalent bonds-covalent bonds between atoms when electronegativity differences are lower than .5. This is usually a result of equal sharing of electrons.

Hydrogen bonds- weak bonds between a hydrogen, which is positively charged, and another atom, which is negatively charged.

Van der Waals interactions- weak intermolecular forces that occur due to the brief attractions and repulsions between atoms when they move around the electron cloud.

Adhesion- is the process of attachment between two different molecules. Water exhibits adhesion when it attracts to surfaces to other polar molecules.

Cohesion- is the process of attachment between two similar molecules. Water exhibits cohesion when it attracts to other water molecules.

Surface tension- a property of liquid that gives it a contractive tendency to resist outside forces. This phenomenon allows bugs to walk on water.

Specific heat- this is the amount of heat required per a unit of mass to raise the temperature of any object by one degree Celsius.

Hydrogen ions- this is an ionized hydrogen in the form of H+, more hydrogen ions would decrease the pH.

Hydroxide ion- this is a diatomic anion that consists of a hydrogen and oxygen, more hydroxide ions would increase the pH.

PH: to measure hydrogen ions in an aqueous solution to determine how acidic or basic a solution is.

Acidity: high number of hydrogen ions in a solution; low pH (0-7).

Alkalinity: the capacity an aqueous solution has to neutralize an acid by removing hydrogen ions.

Buffer: prevents pH of a solution from changing drastically by accepting or donating hydrogen ions.

Carbon-based compounds: organic compounds containing carbons. Ex: carbohydrates, lipids, protiens.

Functional groups: covalently bonded atoms/groups of atoms that effect reactivity and characteristics of the entire molecule.

Hydroxyl: a functional group consisting of OH; an alcohol that is polar and soluble.

Carboxyl: functional group consisting of COOH that is acidic when it ionizes to form COO and hydrogen ions.

Carbonyl: a slightly polar functional group consisting of C=O.

Ketone: a carbonyl functional group with C=O in the middle; ex: fructose.

Aldehyde: a carbonyl functional group with C=O in the end; ex: glucose.

Sulfhydryl: a reactive functional group consisting of SH.

Amino: functional group consisting of NH2 found in amino acids and proteins.

Phosphate: a highly polar, acidic and reactive functional group consisting of OPO3^2-.

Isomers: organic molecules that have different structural formulas and properties but the same molecular formula.

Structural Isomers: organic molecules that have different structures but the same molecular formula. Ex: leucine and isoleucine.

Geometric Isomers: organic molecules that have different geometric structures(cis or trans configuration) but the same molecular formula.

Optical Isomers: enantiomers; organic molecules that are mirror images of each other but have the same molecular formula. This occurs when carbon is attached to four atoms or molecules asymmetrically. Ex: L-amino acid and D-amino acid.

Carbon Skeleton: chain, ring or branch of carbon atoms that form the backbone.