Biology- Module 6: Chemistry in Biology

Atom

building block of matter; contains subatomic particles— neutrons, protons, and electrons.

Nucleus

center of an atom; contains neutrons and protons. In eukaryotic cells, the central membrane-bound organelle that manages cellular functions and contains DNA.

Proton

tiny atomic particle that has mass and a positive electric charge.

Neutron

particle without a charge in an atom’s nucleus. (Neutral)

Electron

tiny atomic particle with little mass and a negative electric charge; an atom’s electrons are equal in number to its protons and are located in a cloud-like region surrounding the nucleus.

Element

natural or artificial substance that cannot be broken down into simpler substances by physical or chemical means.

Isotope

two or more atoms of the same element having different numbers of neutrons.

Compound

substance composed of atoms of two or more different elements that are chemically combined.

Ion

atom that is negatively or positively charged because it has lost or gained one or more electrons.

Ionic Bond

electrical attraction between two oppositely charged atoms or groups of atoms.

Covalent Bond

attraction of two atoms for a shared pair of electrons that holds the atoms together.

Molecule

compound whose atoms are held together by covalent bonds.

Chemical Reaction

change of one or more substances into other substances.

Reactant

substance that exists before a chemical reaction starts; located on the left side of the arrow in a chemical equation.

Product

substance formed by a chemical reaction; located on the right side of the arrow in a chemical equation.

Activation Energy

minimum amount of energy needed for reactants to form products in a chemical reaction.

Catalyst

something that stimulates activity among people or forces.

Enzyme

protein that speeds up a biological reaction by lowering the activation energy needed to start the reaction.

Substrate

reactant to which an enzyme binds.

Active Site

specific place where a substrate binds on an enzyme.

Polar Molecule

molecule with oppositely charged regions.

Van Der Walls Forces

attractive forces between molecules.

Hydrogen Bond

forms when the positive ends of some water molecules are attracted to the negative ends of other water molecules; they cause water’s surface to contract and allow water to adhere to and coat a solid.

Mixture

combination of two or more different substances in which each substance keeps its individual characteristics; can have a uniform composition (homogeneous) or have distinct areas of substances (heterogeneous).

Solution

homogeneous mixture whose components cannot be distinguished and can be classified as liquid, gaseous, solid, or a combination; the method of transport for materials that are dissolved in a stream’s water.

Solvent

substance in which another substance is dissolved.

Solute

substance dissolved in a solvent.

Suspension

Over time, the parts settle to the bottom.

Colloid

Homogeneous mixture where the particles do not settle out.

Acid

solution containing a substance that produces hydrogen ions: (H+) in water.

Base

substance that produces hydroxide ions (OH–) in water .

Buffer

mixture that can react with an acid or a base to maintain the pH within a specific range.

Organic Chemistry

Separate branch of science that is dedicated to the study of compounds containing carbon.

Macromolecule

large molecule formed by joining smaller organic molecules together.

Polymer

large molecule formed from smaller repeating units of identical, or nearly identical, compounds linked by covalent bonds.

Four Macromolecules

Carbohydrates, Lipids, Proteins, Nucleic Acids.

Carbohydrate

organic compound containing carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms for each carbon atom.

Monosaccharides, Disaccharides, Polysaccharides

Different chains of carbohydrates.

Lipids

Large, non-polar biological molecules that vary in structure, store energy in living organisms, and make up most of the structure of cell membranes.

Protein

organic compound made of amino acids joined by peptide bonds; primary building block of organisms. Involved in almost every process within the human body.

Amino Acid

a building block of proteins.

Nucleic Acid

complex macromolecule that stores and communicates genetic information.

Nucleotide

a sub-unit of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base.

Law of Conservation of Matter

Matter cannot be created or destroyed.

Four Elements in Living Things

CHON- Carbon, Hydrogen, Oxygen, and Nitrogen.