Chapter 2 The Chemical Level of Organization Matter – Anything that has mass and takes up space Atom- The smallest particle into which a substance can be broken by ordinary chemical means. Element – Groups of the same type of atom Compound – Two or more elements chemically combined ex. H 2 O

MOLECULE- GROUPS OF ATOMS BONDED TOGETHER & ACTING AS A GROUP ORGANELLES- BASIC STRUCTURES WITHIN CELLS – has a specific function CELL- BASIC UNIT OF LIVING ORGANISMS

TISSUE- TISSUES ARE GROUPS OF CELLS WITH A COMMON FUNCTION. ORGAN- OFTEN LARGE AND COMPOSED OF SEVERAL DIFFERENT TISSUES ORGAN SYSTEM- A GROUP OF ORGANS CARRYING OUT A MAJOR BODY PROCESS ORGANISM- (A GROUP OF ORGAN SYSTEMS IN AN INDIVIDUAL) – any living thing

TYPES OF BONDS (Bonds store energy) COVALENT BONDS- WHEN ATOMS SHARE ELECTONS (the strongest bond) –e.x. Peptide bonds – between C and N in proteins IONIC BONDS- ELECTRONS ARE TRANSFERRED FROM ONE ATOM TO ANOTHER AND IONS ARE FORMED HYDROGEN BONDS- A BOND BETWEEN HYDROGEN AND 2 SMALL ELECTRONEGATIVE ATOMS eg. F, N, O (the weakest bond)

Reactions Chemical Reactions – the process of breaking down chemical bonds and/or forming new ones (a chemical equations shows this) –To do this an activation energy is needed ( the energy that is needed to get the reaction going) Exothermic – there is a net release of energy (it feels warm) Endothermic – there is a net absorption of energy (feels cool)

1. Synthesis – small molecules are combined into larger molecules – always involves the formation of new chemical bonds Ex. A + B  AB Dehydration synthesis (condensation) – the formation of complex molecules by the removal of H 2 O Ex A-B-C-H + HO-D-E  A-B-C-D-E + H 2 0 This is the opposite of hydrolysis

Anabolism – the synthesis of complex organic compounds from simpler compounds (within the body) * requires energy (anabolic steroids)

2. Decomposition – breaks large molecules into smaller ones AB  A + B –Ex. Food broken down –If water is used to breakdown the bonds then it is called hydrolysis (opposite of dehydration synthesis) Ex A-B-C-D-E + H 2 0  A-B-C-H + HO-D-E

Catabolism – the breakdown of complex organic molecules into simpler components, it releases E that can do work Ex. Growth, movement, reproduction

3.Exchange (replacement) – Parts of the reacting molecules are moved around AB + CD  AD + CB (decomp)(synthesis) May absorb or release energy usually in the form of heat

4.Reversible – A + B ⇌ AB Equalibrium – the rates at which the two equations proceed in balance

Enzymes and Chemical Reactions Activation Energy – the amount of E necessary to start a reaction. Enzymes – protein in nature that catalyzes a specific biochemical reaction. (catalyst – accelerates chemical reactions – they enter into a reaction but do not become part of it). They do this by lowering the activation E …… this makes it “safe” for the cell

Remember enzymes are made up of proteins enzyme A + B  AB

Inorganic Compounds Generally do not contain C –Include H 2 O, NaCl, CO 2, NO, and CO –H 2 O – the universal solvent 67% of body is water Dehydration synthesis and Hydrolysis Lubrication (reduces friction) High heat capacity (Carries heat away) Requires a lot of E to change temp. –So thermoregulation

–Hydrophilic – reacts with water (hydro – water philos – loving) –Hydrophobic – doesn’t react w/water (phobic – fear) Electrolytes – soluble inorganic compounds whose ions conduct electrical current in solution ex NaCl  Na + Cl -

Mixtures Mixtures – two or more substances not chemically combined – therefore they retain their own properties –Solutions – evenly combined Solvent – does the dissolving ex. Water Solute – the substance being dissolved ex. Sugar –Suspensions –The particles will spread out and eventually settle – large particles

Example sand in water (whole blood) -Colloid – a mixture that has medium particles – held in solution by their association with water ex. Liquid jello….. Mayonnaise

pH pH IS A WAY TO MEASURE THE ACIDITY OR ALKALINITY (BASICITY) OF A SUBSTANCE ACIDS HAVE A HIGH CONCENTRATION OF (H+) H 3 O + BASES HAVE A HIGH CONCENTRATION OF OH-

Acids and bases are measured on a scale called the pH scale (power of Hydrogen). This scale measures how many hydronium ions (H 3 O + ) are present in a solution (now called just H+). The more hydronium (hydrogen) ions the more acidic (lower) the pH, also the fewer the hydroxide ions (OH - ). The more hydroxide ions the higher the pH (more alkaline – meaning a base) and the fewer the hydronium ions

THE pH SCALE RANGES FROM 1-14 ON THE pH SCALE, 7 IS NEUTRAL A pH BELOW 7 IS ACIDIC A pH ABOVE 7 IS (BASIC) Alkaline (see drawings on board)

THE FARTHER A pH IS FROM 7, THE STRONGER THE SUBSTANCE IS BUFFERS ARE SUBSTANCES THAT HELP STABILIZE pH IN THE BODY BICARBONATE IS THE MOST Important buffer (how CO2 mostly appears in the blood – keeps the blood from becoming to acidic or alkaline)

ORGANIC MOLELCULES ALL ORGANIC MOLECULES CONTAIN CARBON AND ARE FOUND IN LIVING ORGANISMS THERE ARE 4 MAIN GROUPS –CARBOHYDRATES –PROTEINS –LIPIDS –NUCLEIC ACIDS

CARBOHYDRATES ARE SUGARS, STARCHES AND RELATED COMPOUNDS THEIR MOST IMPORTANT FUNCTION IS TO SERVE AS A FUEL SOURCE FOR CELLS THEY ARE ALSO COMPONENTS OF CELL MEMBRANES AND NUCLEIC ACIDS

CARBOHYDRATES ARE CHAINS OF CARBON ATOMS THAT ARE BONDED TO HYDROXYL (OH) GROUPS AND HYDROGEN ATOMS (H) CARBOHYDRATES ARE MADE OF C, H & O C,H & O ARE IN A 1:2:1 RATIO THERE ARE 3 MAIN GROUPS OF CARBOHYDRATES

3 GROUPS OF CARBOHYDRATES MONOSACCHARIDES- SIMPLE SUGARS eg. GLUCOSE, FRUCTOSE, GALACTOSE DISACCHARIDES- 2 SIMPLE SUGARS eg, LACTOSE, SUCROSE, MALTOSE POLYSACCHARIDES- MANY SIMPLE SUGARS eg. STARCH, CELLULOSE, GLYCOGEN SUGARS END IN - OSE

MONOSACCHARIDES GLUCOSE, FRUCTOSE & GALACTOSE ARE ISOMERS. ALL HAVE THE CHEMICAL FORMULA C 6 H 12 O 6 ISOMERS- ARE MOLECULES WITH THE SAME CHEMICAL FORMULA, BUT A DIFFERENT ARRANGEMENT OF ATOMS.

MONOSACCHARIDES: GLUCOSE GLUCOSE- BLOOD SUGAR – cells use this for energy, which is metabolized during cellular respiration. Our major source is from fruits/plants. Plants produce during photosynthesis. NORMAL LEVEL IS mg/100ml. BELOW THIS LEVEL CAN RESULT IN HYPOGLYCEMIA & ABOVE THIS LEVEL CAN RESULT IN DIABETES MELLITUS. DIABETES MELLITUS MEANS “SWEET URINE”

FRUCTOSE FRUIT SUGAR THE SWEETEST OF ALL THE SUGARS

GALACTOSE NOT FOUND FREE IN NATURE, ONLY IN MILK WE CANNOT USE GALACTOSE BUT MUST CHANGE IT TO GLUCOSE

GALACTOSE GLUCOSE ENZYME A (BIRTH)** **ENZYME A IS MISSING IN CHILDREN WITH GALACTOSEMIA. ENZYME B (ONE YEAR)

THIS DISORDER IS CALLED GALACTOSEMIA WHICH MEANS GALACTOSE IN THE BLOOD.

Sx OF GALACTOSEMIA CLOUDING OF THE CORNEA AT ABOUT 4 WEEKS ENLARGED LIVER AND SPLEEN AT ABOUT 4 MONTHS CATARACTS AT ABOUT 6 MONTHS MENTAL RETARDATION AT 12 MONTHS ALL ARE REVERSIBLE, EXCEPT MENTAL RETARDATION

HOW WOULD YOU TREAT GALACTOSEMIA? FEED THE BABY A GALACTOSE FREE FORMULA, NO COW’S OR MOTHER’S MILK. BOTH CONTAIN THIS SUGAR.

DISACCHARIDES – when two monosaccharides bond in a dehydration synthesis reaction H + and OH - are removed and form water LACTOSE: MILK SUGAR GLUCOSE + GALACTOSE SUCROSE: TABLE SUGAR GLUCOSE + FRUCTOSE MALTOSE: MALT SUGAR BREWING INDUSTRY GLUCOSE + GLUCOSE

POLYSACCHARIDES – three or more monosaccharides STARCH: STORAGE FORM OF GLUCOSE IN PLANTS GLYCOGEN: STORAGE FORM OF GLUCOSE IN ANIMALS CELLULOSE: CELL WALLS OF PLANTS FOR STRENGTH ALL 3 ARE LONG CHAINS OF GLUCOSE