Chemistry

J. Cauthers

Living Environment

Atoms

• Atoms are the building blocks of ALL matter.

• Cannot be subdivided any further, through chemical means.

Basic Definitions

• ELEMENT - Substance made from only one type of atom - E.g. Calcium Ca

• COMPOUNDS: made from two or more different atoms and joined chemically in definite proportions– E.g. Carbon Dioxide CO2

Inside and Atom

• Nucleus – Protons (+)– Neutrons (0)

• Isotopes have different #s of neutrons and some are radioactive

• Orbitals– Electrons (-)

• Give atoms their unique properties

Organic vs. Inorganic Compounds

All chemical compounds are broken into two categories:

1) Organic compounds

2) Inorganic Compounds

Organic Compounds

Always contain:

Carbon and Hydrogen

Organic Compounds cont.

Other elements found in organic compounds include:

Oxygen

Nitrogen

Phosphorus

Sulfur

Organic Compounds

Most common elements to appear in organic compounds are:

CHNOPS!!!

Inorganic Compounds

Any compound that isn’t organic

Note: Some contain carbon!!! (CO2)

Agua!!!

Why do we need to talk about water in a class about biology?

Life would not exist were it not for water.

Water

Equation for water is H2O

Is water an organic, or inorganic compound?

Inorganic (no carbon)

Brita

Water is called a POLAR MOLECULE (a partial + and – charge)

The positive end of one water molecule (H end) will be attracted to the negative end of another water molecule (O end).

Pûr

- + - +

Hydrogen

Oxygen

Polar Properties

Cohesion: attraction between water molecules.

Surface tension: holds drops of water together especially at surface.

Perrier

Surface tension in action:

Joe Water

Surface tension again:

Heavy Water (deuterium)

ADHESION attraction of one substance to another

Explains why water is such a good solvent…other substances (polar ones) are attracted to water.

Polar Properties

Adhesion accounts for capillary action or capillarity.

Capillary action : water rises up any narrow space due to attraction with the substance it is interacting with (i.e. glass, or plant roots.)

Acids and Bases

• Water and other compounds can break apart and form ions in solution

• Acids give off H+ ions

• Bases give off OH- ions

pH

• Concentration of H+ ions

• More H+ ions the lower the pH

• Acids – pH 1<7

• Bases – pH >7-14

• Neutral = ~7

Organic Compounds

• Four Types– Carbohydrates– Proteins– Lipids– Nucleic Acids

Carbohydrates

• Building blocks: sugars• Contain C, H and O in a ratio of 2H:1O• Main source of energy• Structural purposes • Long chains form starches• Plants store extra as starch

– Think potatoes!

• Animals store extra as glycogen in liver

Starch

Carbohydrates

• Monosaccharides – single sugars– Glucose, fructose

• Disaccharides – two sugars– Maltose, Sucrose

• Polysaccharides – many sugars– Starch, cellulose

MaltoseSucrose

Proteins

• Building Blocks: amino acids• Contain: C, H, O, N• Control rate of reactions• Regulate cell processes• Form bones and muscles• Transport substances in or out of cells• Help to fight disease

Proteins

• Form 3D structures by folding

• Form enzymes- regulate reactions

Amino Acids

Lipids

• Building Blocks: Glycerol, 3Fatty acids

• Contain: C, H, and O

• Stored energy

• Part of cell membrane

• Steroids and chemical messengers

• E.g. - Fats, oils and waxes

Saturated – only single bonds between C and H

Unsaturated – at least one double bond between C and H

Nucleic Acids

• Building blocks: Nucleotides– 5 C sugar – nitrogenous base– Phosphorus

• Contain C, H, O, N and P

• Store and transmit genetic info

Nucleic Acids

• Two types– DNA - Deoxyribonucleic acid

• Sugar is deoxyribose• Inside nucleus• Double stranded

– RNA – Ribonucleic acid• Sugar is ribose• Involved with protein synthesis• Single stranded

Enzymes

• Biological catalysts that speed up chemical reactions

• Lower energy need to get reaction going (Activation energy)

• Made of proteins

Catalyzed Reactions

Enzymes again…

•The object enzymes work upon are called substrates.

•Specific to the object they work upon

•Most enzymes are named according to what they work upon.

•Naming: change the ending of the substrate name to –ase

Enzyme Naming

Substrate Enzyme

Maltose ??

Sucrose ??

Lipid ??