Elements Pure substance that cannot be broken down chemically into simpler kinds of matter More than 100 elements

Each element unique chemical symbol Consists of 1-2 letters First letter is always capitalized

Atoms The simplest particle of an element that retains all the properties of that element Our understanding of the structure of atoms based on scientific models, not observation

The Protons All atoms of a given element have the same number of protons Number of protons called the atomic number Number of protons balanced by an equal number of negatively charged electrons

The Neutrons The number varies slightly among atoms of the same element Different number of neutrons produces isotopes of the same element

The Electrons Negatively charged high energy particles Travel at very high speeds

Atomic Mass Periodic Table The atomic mass of an atom is found by adding the number of protons & neutrons in an atom Periodic Table Elements are arranged by their atomic number(# of protons) on the Periodic Table

Compounds A compound is a pure substance made up of atoms of two or more elements

Molecules are the simplest part of a substance that retains all of the properties of the substance and exists in a free state Some molecules are large and complex

Chemical Formulas Subscript after a symbol tell the number of atoms of each element H20 has 2 atoms of hydrogen & 1 atom of oxygen Coefficients before a formula tell the number of molecules 3O2 represents 3 molecules of oxygen or (3x2) or 6 atoms of oxygen

Covalent Bonds Formed when two atoms share one or more pairs of electrons Video

Ionic Bonds Some atoms become stable by losing or gaining electrons Atoms that lose electrons are called positive ions Video

Ions Ions are atoms with either extra electrons or missing electrons. A normal atom is called a neutral atom. That term describes an atom with a number of electrons equal to the atomic number.

pH Scale logarithmic scale for comparing the relative concentrations of hydronium ions and hydroxide ions in a solution ranges from 0 to 14 Each pH is 10X stronger than next e.g. ph 1 is 10 times stronger than ph 2

pH Scale continued An Acid contains an excess of H+ hydrogen ions A base contains an excess of OH-hydroxide ions. On the pH scale Acids are 0-6 and Bases are 8-14. What is 7?

the lower the pH the stronger the acid the higher the pH the stronger the base pH 7.0 is neutral

Buffers Control of pH is very important Most enzymes function only within a very narrow pH Control is accomplished with buffers made by the body Buffers keep a neutral pH (pH 7)

Buffers neutralize small amounts of either an acid or base added to a solution Complex buffering systems maintain the pH values of your body’s many fluids at normal and safe levels

Organic vs. Inorganic Inorganic lack a carbon-hydrogen combination Ex) water, salts (NaCl, KCl) Organic substances always contain both carbon and hydrogen

Macromolecules Carbohydrates Lipids Proteins Nucleic acids

Carbohydrates Elements that make up carbs: C H O; Always 2:1 ratio between H and O Function of carbs Main energy source Structural component: cell walls, insects exoskeleton Used by cells to recognize other cells: receptors

Carbohydrate

Monomer of carbohydrates Monosaccharides: one sugar: ex: Glucose, fructose, galactose; chemical formula = C6H12O6 Polymers Disaccharides: two monomers: ex: sucrose, maltose Polysaccharides: many monomers: ex: starch, glycogen, cellulose

Dehydration Synthesis & Hydrolysis

Lipids Examples: Fats, Waxes and Oils (Mostly C & H); no ratio between H and O Function of lipids Stored energy Structural components

Lipids are also made of Monomers: 1 glycerol 3 fatty acids Two types of lipids Saturated: contains max. # H atoms. Unsaturated: contains some C=C bonds.

A Representative Fatty Acid

Proteins Elements of proteins: C, H, O, N Functions Control rate of reactions Regulates cell processes (enzymes) Building materials (collagen & elastin, coloration pigments) Fight disease (antibodies)

Building blocks of proteins amino acids (AA): are monomers or building blocks of proteins The protein is the Polymers: proteins are also called polypeptides One bonded to another AA Peptide bonds are used to bond one amino acid to another to form proteins AA-AA-AA-AA-AA-AA Draw an AA, R=H----glycine; R=CH3---alanine

A large protein chain made of small amino acids http://www.teachertube.com/view_video.php?viewkey=aa818e40a6b8475f0d28 Go to Section:

Amino Acids General structure Alanine Serine Amino group Carboxyl group General structure Alanine Serine Go to Section:

Some Amino Acids

Nucleic Acids Elements of nucleic acids: C, H, O, N, P Function of nucleic acids Store & transmit genetic info.; the building blocks to our genetic code (DNA) Monomers of nucleic acids are called Nucleotides Three nucleotides of nucleic acids are: 5-C sugar, Nitrogenous base, phosphate group Polymer DNA (deoxyribonucleic acid) RNA (ribonucleic acid) Polynucleotide held together covalently

The 2 Types Of Nucleic Acids 1. DNA (deoxyribonucleic acid)- our hereditary info. directs all cell activities 1st identified as double helix 1953 by Watson and Crick 2. RNA (ribonucleic acid)- transcribes hereditary info. (copies DNA) to make a protein the body needs * this means that proteins determine the nature and activities of the cell

The Nucleotide All nucleotides are identical The only difference is the type of nitrogenous base they have. There are 4 types: Guanine, Cytosine, Adenine and Thymine. These bases pair up in a specific way to make the rungs of the DNA Double Helix.

Review Macromolecules Carbohydrates- Made up of sugars Proteins Made up of amino acids Lipids Fatty acid and glycerol Nucleic acids Nucleic acids C, H, O, N, P

Energy and Chemical Reactions Living things undergo thousands of chemical reactions as part of the life process

Certain chemical substances (catalysts) can speed up or slow down a reaction. Biological catalysts are called enzymes If it ends in ase it is an enzyme.

Enzymes are an important class of catalysts in living organisms Mostly protein Thousands of different kinds Each specific for a different chemical reaction

Enzyme Structure Enzymes work on substances called substrates Substrates must fit into a place on an enzyme called the active site Enzymes are reusable! End in –ase -Sucrase -Lactase -Maltase

Enzymes Video

Active Site A restricted region of an enzyme molecule which binds to the substrate. Enzyme Substrate Active Site

Enzyme Action Enzyme-Substrate Complex substrates – the reacting molecules; the substance(s) that the enzyme works on, active site – that portion of the enzyme into which the reacting molecules fit product – the substance that results from the enzymatic activity

Lock + Key- refers to how the active site + substrate fits together there is only one key to a lock there is only one substrate to an active site

Enzyme video http://bcs.whfreeman.com/thelifewire/content/chp06/0602001.html Animation

Concept Map Carbon Compounds Lipids Nucleic acids Proteins include Carbohydrates Lipids Nucleic acids Proteins that consist of that consist of that consist of that consist of Sugars and starches Fats and oils Nucleotides Amino Acids which contain which contain which contain which contain Carbon, hydrogen, oxygen Carbon,hydrogen, oxygen, nitrogen, phosphorus hydrogen,oxygen, nitrogen, Go to Section:

To add- products, reactants importance of water To add- products, reactants importance of water. Hydrolysis dehydration synth