Biochem test

Atom

Atom

the basic unit of matter

Element

a substance consisting of the same type of atoms

Molecule

Two or more atoms chemically bonded together

Compound

A molecule including more than one element

Proton

Positive charge, located in the nucleus, mass ~ 1 amu

Neutron

Neutral charge, located in the nucleus, mass ~ 1 amu

Electron

Negative charge, located in the electron shell, negligible mass

Atomic Number

equal to the number of protons

Atomic Mass

equal to the number of protons plus neutrons

Isotopes

Different isotopes of the same element have the same number of protons and a different number of neutrons

Radioactive isotopes

Are useful as tracers and can be damaging to DNA

Covalent bond

A bond that forms when two atoms share electrons

Ionic bond

A bond that happens when two ions with opposite charges attract and are held together

Cation

An ion with a positive charge

Anion

An ion with a negative charge

Electronegativity

The attraction (pull) for shared electrons

Polar Molecules

Molecules with atoms that have different electronegativities

Nonpolar molecules

Molecules with atoms that have equal electronegativity

Hydrogen Bonding

Weak bonds between a hydrogen atom in one molecule and a more electronegative atom of another molecule

Cohesion

The tendency of molecules of the same kind to stick together

Adhesion

The tendency of two different types of molecules to stick together

Heat capacity

The amount of energy it takes to raise the temperature of the liquid

Evaporative cooling

When water evaporates, the molecules with the greatest energy leave the surface, and the liquid that remains cools down

pH

Measures how acidic or basic a solution is

pH Scale

Ranges from 0 -14, with pH 7 being neutral

Organic molecules

Molecules that contain carbon with hydrogen

Acids

Often taste sour, can burn skin & eyes, and dissolve metals

Bases

Can taste bitter, sweetish, or salty, and react more easily with protein than with metal

Carbon

Can covalently bond with up to four other atoms.

Carbon Bonds

Can bond with other carbon atoms in single, double, or triple bonds.

Organic Molecules

All living things contain carbon.

Abundant Elements in Living Organisms

Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorous, Sulfur.

Macromolecules

Large molecules that make up living things.

Types of Organic Macromolecules

Carbohydrates, Lipids, Proteins, Nucleic Acids.

Monomers

The building blocks of macromolecules.

Polymers

Formed when multiple monomers are bonded together.

Condensation Reaction

Monomers link to form polymers through this reaction.

Hydrolysis Reaction

The opposite of a condensation reaction, where water is added to a polymer.

Carbohydrates

The body's preferred and first source of energy.

Carbohydrate Ratio

1:2:1 C:H:O.

Monosaccharides

Examples include glucose, fructose, galactose.

Disaccharides

Example: sucrose (fructose + glucose → sucrose).

Polysaccharides

Examples include starch, glycogen, cellulose, and chitin.

Proteins

Made up of carbon, hydrogen, oxygen, and nitrogen.

Amino Acids

The monomer of proteins, there are twenty different amino acids.

Peptide Bond

Amino acids are linked together by this bond.

Polypeptide

A chain of amino acids.

Enzymes

Protein molecules that speed up chemical reactions.

Active Site

The place on the enzyme where the substrate binds.

Lipids

Large, nonpolar organic molecules that are hydrophobic.

Fats

Function is energy storage.

Saturated Fats

Solid at room temperature and have all single bonds between carbon atoms.

Unsaturated Fats

Liquid at room temperature and contain at least one double bond between carbon atoms.

Trans Fats

Usually artificially created and not good for health.

Phospholipids

Major component of all cell membranes.

Steroids

Lipids in which the carbon skeleton contains 4 fused rings.

Nucleic Acids

Store and transmit genetic information.

Nucleotide

The monomer of a nucleic acid.

DNA

Double stranded helix, deoxyribonucleic acid.

RNA

Single stranded helix, ribonucleic acid.