chemistry of life. i. nature of matter a. atoms b. chemical bonding ii. water and solutions a....

Chemistry of LifeChemistry of Life

Chemistry of Life

I. Nature of Matter A. Atoms B. Chemical Bonding

II. Water and Solutions A. Cohesion & Adhesion B. Polarity C. Acid & Bases

More Chemistry….

III. Chemistry of Cells

A. Carbohydrates

B. Lipids

C. Proteins

D. Nucleic Acids

IV. Energy and Chemical Reactions

A. Energy

B. Enzymes

Atoms

Smallest unit of matter that cannot be broken down by chemical means.

Protons – (+)Neutrons – (0)Electrons – (-)

Element v. Compound

Element – one kind of atomCompound – two or more

different elements

Periodic Table…..

Bonding….

Covalent: share electronsShells….

More bonding…

Hydrogen: occurs between polar molecules Water is a polar molecule: opposite ends of the

molecule have opposite charges

Even more bonding…

Ionic: gaining or losing electrons; become charged and…we know…opposites attract!

Recap… http://www.youtube.com/watch?v=QqjcCvzWwww

Cohesion, Adhesion, and Surface Tension

Cohesion: molecules attracted to each other – causes surface tension

Adhesion: molecules

attracted to others – end

up with capillary action.

Cohesion and adhesion responsible for Giant Redwoods

Aqueous Solutions

Solution: mixture where one or more substances are evenly distributed in another substance.

Ex. Salt dissolves in water

Polarity: polar easily

dissolves in water;

nonpolar does not dissolve well in water (oil

and water)

Acids and Bases

When a hydrogen is stripped away from a covalent bond it leaves as an ion H+ (called a hydrogen ion), if it is stripped from a water molecule it leaves OH- a hydroxide ion

Covalent bonds of water often break spontaneously-ionization– H2O → H+ + OH-

pH Scale

Changes in acidity (or basicity) due to an increase or decrease in hydrogen ions are measured with the pH scale

pH scale is used to determine the acidic or basic nature of a solution compared to pure water

Pure water has an equal concentration of hydrogen and hydroxide ions pH = 7

Chemistry of Cells

Organic compounds are found in living things – contain carbon and are covalently bonded.

Four types: carbohydrates, lipids, protein, and nucleic acids.

Organics…

Carbohydrates: C, H, O 1:2:1 (ex. Glucose – source of energy)

Lipids: aka fats – nonpolar (remember the oil and water)… stores energy

Proteins: chains of amino acids Nucleic acids: store and transmit heredity

information – DNA, RNA ATP is the main source of energy in a cell.

Enzymes

Starting a chemical reaction requires activation energy (energy to start “activate”).

Enzymes speed up reactions by lowering activation energy.

More enzymes…

Enzymes bind only certain substrates (in other words…they are picky!)

pH and temperature affect enzyme activity…

HOW?