Biology Vocab. Chapter 2

Element

Simplest form of an substance; cannot be broken down into simpler substances

Diatomic Elements

Compounds covanlently bonded having two atoms of the same elementEx: H2, N2, O2, F2, Cl2, Br2, I2

Compound

A substance made up of atoms of two or more different elements joined by chemical bonds

Molecule

The smallest unit of a substance that keeps all of the physical and chemical properties of that substance; can consist of one atom or two or more atoms bonded togetherEx: A molecule is the result of a covalent bond between two nonmetals (CO2)

Ion

An atom, radical, or molecule that has gained or lost one of more electrons and has a negative or positive chargeIons are charged atoms and can form crystals, like salt.

Cohesion

The force that holds molecules of a single material together

Adhesion

The attractive force between two bodies of different substances that are in contact with each other

Solution

A homogeneous mixture of two or more substances uniformly dispersed throughout a single phase.Review solute and solvent, and remember a solute can be a solid, liquid, or gas.

Acid

Any compound that increases the number of hydronium ions when dissolved in water; acids turn blue litmus paper red and react with bases and some metals to form salts

Base

Any compound that increases the number of hydroxide ions when dissolved in water; bases turn red litmus paper blue and react with acids to form salts

Carbohydrate

Any organic compound that is made of carbon, hydrogen, and oxygen and that provides nutrients to the cells of living things(Hint: Say CHO) Ex: C6H12O6 = Glucose

Monosaccharide

A simple sugar that is the basic subunit of a carbohydrate (mono means one)Ex: Glucose, fructose, galactose C6H12O6

Dissacharide

A carbohydrate made of two sugar units (two monosaccharides joined together) with the elimintation of one water to form the bond of the carbohydrateEx: sucrose, lactose, maltose C12H22O11

Polysaccharide

A carbohydrate made of two sugar units (two monosaccharide joined together) with the elimination of one water to form the bond of the carbohydrateEx: StarchStarch is found in potatoes, rice, corn and turns black in the presence of the indicator iodine.

Lipid (fat)

A type of organic molecule that does not dissolve in water (nonpolar), including fats and steroids; store energy and make up cell membranesEx: Chains of fatty acids plus glycerol = lipids

Energy

Required by living cells for proper functioningIn living cells during respiration, glucose is chemically changed into ATP to run the cell's machinery.

Activation Energy

The minimum amount of energy required to start a chemical reactionFind graph.

Enzyme

A type of protein that speeds up metabolic reactions in plants and animals without being permanently changed or destroyed

Active Site

The site on an enzyme that attaches to a substrate

Protein

An organic compound that is made of one or more chains of amino acids and that is a principal component of all cellsEx: Chains of amino acids = Protein

Amino Acid

Any one of twenty different organic molecules that contain a carboxyl and an amino group and that combine to form proteins

Nucleic Acid

An organic compound, either RNA or DNA, whose molecules are made up of one or two chains of nucleotides and carry genetic information

Nucleotide

In a nucleic-acid chain, a subunit that consists of three things: a sugar, a phosphate, and a nitrogenous base

DNA

Deoxyribonucleic acid; the material that contains the information that determines inherited characteristics

RNA

Ribonucleic acid; a natural polymer that is present in all living cells and that plays a role in protein synthesis

ATP

Adenosine triphosphate; an organic molecule that acts as the main energy source for cell processes; composed of a nitrogenous base, a sugar, and three phosphate groups (as opposed to adenosine diphosphate = two phosphate groups)

pH

A value used to express the acidity or alkalinity of a solution; defined as the logarithm of the reciprocal of the concentration of hydronium ions;An acronym for the % (p) of hydronium ionspH = 7 (neutral), pH < 7 (acidic), and a pH > 7(basic)

Neutralization

Acid + base ? salt + water