chapter 2 the chemical level of organization
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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 - PowerPoint PPT PresentationTRANSCRIPT
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. H2O
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)
Types of 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)
Reactions1. 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 H2O
Ex A-B-C-H + HO-D-E A-B-C-D-E + H20
This is the opposite of hydrolysis
• Anabolism – the synthesis of complex organic compounds from simpler compounds (within the body) * requires energy
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 + H20 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 and H– Include H2O, NaCl, CO2, NO, and CO– H2O – 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+) H3O+
• 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 (H3O+) are present in a solution. The more hydronium 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 C6H12O6
• 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 80-120 mg/100ml.
• BELOW THIS LEVEL CAN RESULT IN HYPOGLYCEMIA & ABOVE THIS LEVEL CAN RESULT IN DIABETES MELLITUS. DIABETES MELLITUS MEANS “SWEET URINE”
FRUCTOSE
FRUIT SUGARTHE 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 SUGARGLUCOSE + GALACTOSE
SUCROSE: TABLE SUGARGLUCOSE + FRUCTOSE
MALTOSE: MALT SUGAR BREWING INDUSTRYGLUCOSE + 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