Chapter 2Oliver Thomas

AtomsUnable to be cutBasic unit of matterMade of protons, neutrons, and electronsProtons are positiveNeutrons carry no chargeElectrons are negative

Elements and IsotopesMore then 100Represented by one or two letter symbolsDifferent numbers of neutronsIdentified by their mass numbersSome are radioactiveCan be dangours

Chemical CompoundsFormed by two or more in definite

proportions

Chemical BondsMain types are ionic bonds and covalent

bondsIonic Bon- The are created by one or more

are transferred from one atom to anotherCovalent bonds-Created when electrons are

shared between atoms

The Water MoleculeLike molecules, water molecules are neutral.A water molecule is polar because there is an

uneven distribution of electrons between the oxygen and hydrogen atoms.

Solutions and SuspensionsWater is not always pure-it is often found as

part of a mixture.A mixture is a material composed of two or

more elements or compounds that are physically mixed together but not chemically combined.

The Chemistry of CarbonCarbon atoms have four valence electrons.Each electron can join with an electron from

another atom to form a strong covalent bond.Carbon can bond with many elements,

including hydrogen, oxygen, phosphorus, sulfur, and nitrogen.

MacromoleculesMacromolecules are made from thousands or

even hundreds of thousands of smaller molecules

The smaller units, or monomers, join together to form polymers.

Four groups of organic compounds found in living things are carbohydrates, lipids, nucleic acids, and proteins

CarbohydratesCarbohydrates are compounds made up of

carbon, hydrogen, and oxygen atoms.Living things use carbohydrates as their

main source of energy.Plants and some animals also use

carbohydrates for structural purposes.

LipidsLipids are made mostly from carbon and

hydrogen atoms.Lipids can be used to store energy.Some lipids are important parts of biological

membranes and waterproof cover

Nucleic acidsNucleic acids are macromolecules containing

hydrogen, oxygen, nitrogen, carbon, and phosphorus.

Nucleic acids store and transmit hereditary, or genetic, information.

There are two kinds of nucleic acids- Ribonucleic acid, and deoxyribonnucleic

ProteinsProteins are macromolecules that contain

nitrogen as well as carbon, hydrogen, and oxygen.

Proteins are polymers of molecules called amino acids.

Chemical ReactionsChemical reaction is a process that changes

one set of chemicals into another set of chemicals.

Chemical reactions always involve the breaking of bonds in reactants and the formation of new bonds in products

Energy In ReactionsChemical reactions that release energy often

occur spontaneously.Chemical reactions that absorb energy will

not occur without a source of energy.

EnzymesCells use enzymes to speed up chemical

reactions that place in cells.

Enzymes are very specific, generally catalyzing only one chemical reaction

Enzymes ActionEnzymes provide a site where reactants can be

brought together to react.