Chap. 2 Debra Owens

Atoms Atoms Study of chemistry with basic unit of matter. Subatomic make up atoms: Protons, neutrons, and electrons. Nucleus: center of atom Electrons: negative charge

Elements Elements: pure substance that consists entirely of one type of atom. Isotopes: different number of neutrons in an atom. Atoms have the some number of with electrons and chemical properties.

Chemical Compounds Compounds: two or more elements in definite proportions

Chemical Bonds Ionic & covalent Bonds are the main bonds Ionic bonds: transferred from one atom to another. Ions: positively and negatively charges atoms Covalent Bond: shared between atoms Molecule: smallest unite of most compounds Van der Waal forces: scientist who discovered chemists

Water Molecule Water molecule is polar Uneven distribution between the oxygen and hydrogen atoms. Cohesion: attraction between molecules of same properties. Adhesion: attraction between molecules of different substance.

Solutions and Suspensions Mixture: composed of two or more compounds. Solutions: evenly distributed throughout the solution. Solute: substance that dissolve Solvent: substance that solute dissolve Suspensions: mixture of water and nondissolve material

Acids, Bases, and pH pH scale: concentration of H icons in solutions Acid: any compound the forms H. Base: compound that produces hydroxide ions Buffers: weak acids or base, react with strong acids or bases, changes to pH

The Chemistry of Carbon Has a form of millions of different large and complex structures.

Macromolecules Monomers are joined together to form polymers Carbohydrates, lipids, nucleic acids, and protein are four groups of organic compounds

Carbohydrates Compounds made up of carbon, hydrogen and oxygen atoms. Living things use carbohydrates as their main source. Monosaccharide: single sugar molecules Polysaccharides: Large macromolecules formed from monosaccharide.

Lipids Large and varied group of biological molecules that generally not soluble in water. Used to store energy. Some are important parts of biological membranes and waterproof coverings.

Nucleic Acids Contain hydrogen, oxygen, nitrogen, and phosphorus Stores and transmit hereditary or genetis information Ribonucleic and deoxyribonucleic acid are both nucleic acids.

Protein Macromolecules that contain nitrogen: carbon, hydrogen and oxygen Amino acids: polymers of molecules Some proteins control rate of reactions Used to form bones and muscles Helps fight disease

Chemical Reactions A process that changes one set of chemicals Reactions involve breaking bonds in reactions formations of new bonds in products.

Energy in Reactions Release energy often occur spontaneously. Absorb energy that will not occur without a source of energy. Activation energy: energy that is needed to get a reaction started

Enzymes Proteins that act as biological catalysts Catalyst: substance that speeds up rate of a chemical reaction. Cells use enzymes to speed up chemical reactions that take place in cells

Enzyme Action Substrates: reactions of enzyme-catalyzed reaction