Class Notes Honors Biology “LIFE CHEMISTRY”

Water The most important property of the water molecule is that it is charged on each end

MOLECULEMOLECULE WATERWATER O H H + -

Mixture: Substance composed of two or more elements or compounds that are mixed together but not chemically combined ex - salt and pepper / sugar and sand

Suspensions: Mixture of water and a non- dissolved material Material does not dissolve and does not settle in the liquid It remains ‘suspended’ Ex - Blood, Oil and Water, Gravy

Solution: A substance dissolves in another Ex - Sugar in water

Solvent: The substance that does the dissolving Ex - The water

Solute: The substance that is dissolved Ex - The sugar

Acids and Bases

Acids: Compounds that release hydrogen ions ( H + ) into solution Ex - Hydrochloric acid (HCl) HCl ---> H + + Cl -

Acids tend to have the following characteristics: ionize in water to generate hydrogen ions [H+] turn litmus paper RED induce a sour taste (e.g. lemon) have a pH less than 7

Bases: Compounds that release hydroxide ions (OH - ) into solution Ex - Sodium Hydroxide (NaOH) NaOH ---> Na + + OH -

Bases tend to have the following characteristics: ionize in water to generate hydroxide ions [OH-] turn litmus paper BLUE induce a bitter taste feel slimy Have a pH more than 7

Look at each of the following product and see if you can guess if it is an ACID or a BASE....

ACID OR BASE ???? ?

ACID

ACID OR BASE ???? ?

BASE

ACID OR BASE ???? ?

ACID

ACID OR BASE ?????

ACID

ACID OR BASE ?????

BASE

ACID OR BASE ?????

ACID

pH Scale: A measurement system that indicates the relative concentrations of hydrogen ions [H+] and hydroxide ions [OH-]

pH Scale runs from 0 to 14 A difference of 1 on the scale is actually a difference of 10 times the relative strength of the acids or bases: ‘0’ means 10 0 = 1 ‘1’ means 10 1 = 10 ’2’ means 10 2 = 100 ‘3’ means 10 3 = 1000 etc.....

pH scale Page 66 in your book Increasingly Acidic Increasingly Basic Neutral Stomach Acid Lemon Juice Vinegar/Cola Lye Tomatoes Household Bleach Household Ammonia Normal rainwater Shampoo Soap Urine Baking Soda Human Blood Sea Water Tears Saliva Water Oven Cleaner

Acidic = 0 to 6 = H + ion concentration (0 is highly acidic) Neutral = 7 = Equal conc. of H + and OH - ions (water) Basic = 8 to 14 = OH - ion concentration (14 is highly basic) Neutralize an acid by adding a base Neutralize a base by adding an acid H + + OH > H 2 O

Inorganic vs Organic Compounds Organic means the compound contains Carbon Inorganic means it does not contain Carbon

Carbon: Living things contain carbon Carbon is special because of the strong and stable bonds that it can form Carbon has 4 electrons in its second energy level This means that it can form 4 single covalent bonds

Polymerization: Large compounds (polymers) formed from smaller ones (monomers) Macromolecules: are giant polymers

4 Basic Molecules of Life: CARBOHYDRATES LIPIDS PROTEINS NUCLEIC ACIDS

CARBOHYDRATES : (Sugars and Starches) Contain energy stored in the bonds that make the molecules When the bonds are broken the energy is released Glucose is the basic energy source for organisms

3 Kinds of Carbohydrates: MONOSACCHARIDES DISACCHARIDES POLYSACCHARIDES

MONOSACCHARIDES : MONO means “ONE” 3 KINDS: GLUCOSE (sugar in green plants) FRUCTOSE (sugar in fruit) GALACTOSE (sugar in milk) Formula is C 6 H 12 O 6 They differ in the arrangement of atoms

DISACCHARIDES : DI- means “TWO” 3 KINDS: SUCROSE - Table Sugar (glucose + fructose) LACTOSE - Milk Sugar (glucose + galactose) MALTOSE - Malt Sugar (glucose + glucose)

POLYSACCHARIDES : -POLY- means “MANY” Made of long strings of simple sugar molecules

POLYSACCHARIDES : 3 KINDS - STARCH - CELLULOSE - GLYCOGEN

STARCH A Large Storage Molecule in Plants Found in potatoes, bread, pasta, etc.

CELLULOSE A large molecule used as Structure in Plants (Fiber) Fiber is Important in Human Diet Cannot be digested in Humans - Cleans your Intestines

GLYCOGEN Large storage molecule in animals Broken down for energy as you need it

Dehydration Synthesis: Dehydration = loss of water Synthesis = putting together This reaction forms complex carbohydrates by combining two or more monosaccharides Each time a bond is formed, a molecule of water is removed (dehydration)

Hydrolysis : Reaction occurs when polysaccharides are split apart to form monosaccharides Means “water splitting” Reverse reaction of dehydration synthesis

LIPIDS : Organic compounds that are waxy or oily Made of Fatty Acids + Glycerol Used to store energy, form biological membranes, used as chemical messengers FATS / OILS / WAXES / PHOSPHOLIPIDS / STEROLS

FATS / OILS / WAXES : Fats and waxes are solid at room temperature, oils are liquid Plants and animals use lipids to store energy When broken down, lipids produce more energy than carbohydrates Fats can be Saturated or Unsaturated or Polyunsaturated

Saturated - Has every carbon joined by a single bond, it contains the maximum number of hydrogen atoms Unsaturated - contains a pair of carbons that is joined by a double bond Polyunsaturated - contains several double bonds

Polyunsaturated fats are liquid at room temperature and are used as cooking oils. Ex - sesame oil, peanut oil, corn oil, olive oil Replacing saturated fats in your diet with polyunsaturated fats may help prevent heart disease

PHOSPHOLIPIDS : Contains parts that dissolve well in water and parts that don’t dissolve well in water Liposomes - spontaneous forming balloon-like structures with a double layer of lipid molecules (“lipid bilayer”) Lipid Bilayers form Cell Membranes

STEROL LIPIDS : Important in building cells and carrying messages from one part of the body to another (hormones) Cholesterol - common sterol - important in many animal cells - if excessive in diet, it is a risk factor in heart disease

PROTEINS : FUNCTIONS of Proteins include: Movement, Structure, Transport, Biochemical Control, Storage, Regulation, Defense Are Polymers of more than 20 different AMINO ACIDS Peptide Bond: Type of covalent bond that joins two amino acids

Catalyst: Any substance that speeds up the rate of chemical reactions without being changed by the reaction They work by lowering the “start- up” energy of a reaction Enzymes are the catalysts in living organisms

Enzymes: are a special group of proteins that speed up the chemical reactions that are necessary for the ordinary activities of life simple cell may contain over 2000 different enzymes, each a catalyst for a different reaction

Substrates: are the substances that are affected by an enzyme Active Site: the region that substrates bind to on an enzyme (like a “Lock and Key”)

Regulating chemical pathways, synthesizing materials needed by cells, releasing energy, and transferring information Involved in digestion, respiration, reproduction, vision, movement, thought, and even making other enzymes Enzyme Functions:

NUCLEIC ACIDS : Polymers of Nucleotides 2 Kinds : RNA Ribonucleic Acid - Makes Proteins DNA Deoxyribonucleic Acid- Store and Transmit Genetic Information

pH scale Page 66 in your book Increasingly Acidic Increasingly Basic Neutral Stomach Acid Lemon Juice Vinegar/Cola Lye Tomatoes Household Bleach Household Ammonia Stomach Acid Normal rainwater Shampoo Soap Urine Baking Soda Human Blood Sea Water Tears Saliva Water Oven Cleaner Copy this scale for your notes