What’s so special about water? It is a great solvent. It holds heat very well. It is the most important inorganic molecule. It is a polar compound Water, pH and Biological Molecules

Water as a Solvent Dissolving table salt (sodium chloride)

This means that ice forms an insulating blanket over water. Water Is Lighter as Solid than as a Liquid

Water Has High Surface Tension The attraction of one water molecule for another also accounts for its ability to hold huge amounts of heat.

Water is a Polar Compound Hydrogen ends holds slightly positive charges Oxygen end holds a slightly negative charge p+p+ p+p+ 1H1H 1H1H (+) (--)

pH is a Big Deal pH is a measure of proton (hydrogen ion or H + ) concentration. High pH (base) = few H + ions ; more OH - ions Low pH (acid) = lots of H + ions

Acids and Bases Acid = H + DonorsBase = H + Acceptors

ORGANIC COMPOUNDS Making Molecules Because carbon contains 4 electrons in its outer shell, it can share electrons with many different atoms in an “attempt” to fill its outer shell. Organic compounds are carbon compounds, made by living things

Carbon is the Central Atom of Life. glucose amino acids fat

Some Useful Nomenclature

In Biology, Shape Matters Its not just chemical formula, it’s the shape of the molecule that lets it do its “job”. Never forget the axiom – structure dictates function. Some biological molecules.

Ah, That Smell! Once again, shape matters. It’s the good fit between odorant and receptor molecule that lets us detect aromas.

Molecules of Life Start with water, add lots of small carbon- containing molecules and ……. Four Major Classes of Biological Molecules How do you build a cell?

Rules of the Game Macromolecules are built by linking a set of building blocks (monomers) together into long chains (a polymer). Each hexagon is this figure is a monomer, building blocks linked together to form a polymer. Monomers – basic units that repeats over and over in organic compounds

Macromolecules Are Built By Linking a Set Of Building Blocks (Monomers) Together Into Long Chains (A Polymer).

FOUR TYPES OF ORGANIC COMPOUNDS CARBOHYDRATES –SUGARS AND STARCHES LIPIDS –FATS PROTEINS –HAIR, FINGERNAILS, MUSCLES NUCLEIC ACIDS –DNA AND RNA (GENETIC MATERIAL)

CARBOHYDRATES ELEMENTS – C, H AND O RATIO H:O = 2:1 MONOMER = MONOSACCHARIDE EXAMPLES –SUGARS & STARCH MAIN FUNCTION –QUICK ENERGY

Glucose: A Simple Carbohydrate Used For Energy Production and as a Building Block For Complex Carbohydrates

Linking Simple Sugars – the First Step to a Polymer and the Last Step to Some Familiar Compounds MONOSACCHARIDESDISACCHARIDES

Some Familiar and Important Complex Carbohydrates 3 OR MORE REPEATING UNITS = POLYSACCHARIDE

Carbohydrates are Central Players in Energy Production and Storage

LIPIDS ELEMENTS: C, H and O RATIO OF H:O = More H than O MONOMER = Glycerol and 3 Fatty Acids EXAMPLES –Fats, Oils and Waxes MAIN FUNCTION –Storage –Energy reserves –Cell membranes GlycerolGlycerol FA

Lipids are Hydrophobic Molecules That Exist In Three Primary Forms Sterol Fat Phospholipid

Fats Are Made By Linking Fatty Acid Chains to Glycerol, a Three Carbon Molecule Space-filling model of a fat A fatty acid

Fats are Used in Energy Storage and Production

The Degree Of Saturation In A Fat Affects Its Physical And Nutritional Properties Where are the double bonds?

The Degree Of Saturation In A Fat Affects Its Physical And Nutritional Properties Where are the double bonds? saturated monounsaturated polyunsaturated

Sterols Are Part of Cellular Membranes and Act as Hormones Note the four ring structure common to all sterols.

Sterols As Hormones Estrogen, testosterone, progesterone, and corticosteriods (cortisol) are all steroid hormones.

Sterols As Hormones “Designer steroids” are major sporting news where they have been used illegally in track and field, baseball, football and countless other sports. A heavily muscled Linford Christie who was disqualified from international competition after testing positive for a banned steroid.

Phospholipids are Building Blocks of Cellular Membranes The hydrophilic head group and hydrophobic tails are the keys to phospholipid function.

Hydrophilic Head Group And Hydrophobic Tails Are The Keys To Phospholipid Function Phospholipids have a Jekyll and Hyde personality.

Phospholipids Form Biological Membranes THE CELL MEMBRANE

PROTEINS Basic building blocks of living material ELEMENTS: C, H, O and N MONOMER: Amino Acids –20 different amino acids USES –Hair, Muscles, Fingernails –Enzymes – carry out chemical reactions –Transport in cells FORMS PEPTIDE BONDS BETWEEN A.A.

Protein Proteins are THE key elements of life. Forget DNA, proteins rule. Remember the principle - Structure determines Function. Since proteins are the key players of the cell, it follows that protein structure determines cell function.

Some of the Diverse Functions of Proteins

Strands of the Protein Keratin Create Hair

Proteins are Linear Chains of Linked Amino Acids

A Common Thread and a Unique Identity R – Residual Group *side chain changes Amino Group – NH 2 Single Hydrogen - H Acid or Carboxyl Group – C=O, OH (Side chain)

PEPTIDE BONDS 1 amino acid 2 amino acids linked together – dipeptide 3 or more amino acids linked together - polypeptide Peptide bonds

Amino Acids, Peptide Bonds, Polypeptides, Protein Peptide bonds Proteins are linear chains of 20 different building blocks called amino acids. Amino acids are linked by peptide bonds – a form of covalent bond.

Proteins are Folded Structures Whose Shape (and therefore function) Depends on Amino Acid Sequence

Nucleic Acids There are two kinds of nucleic acids, DNA and RNA. Both are involved in the storage and flow of information from gene to gene product. DNA

NUCLEIC ACIDS ELEMENTS: C, H, O, N P and S MONOMER: Nucleotides USES: DNA and RNA –Genetic material –Controls the cells activities

NUCLEOTIDES SUGAR GROUP DEOXYRIBOSE RIBOSE (RNA) PHOSPHATE GROUP NITROGENOUS BASE ADENINE GUANINE CYTOSINE THYMINE URACIL (RNA)

Nucleotides fuel the cell and coordinate its metabolism. Nucleotides are Important in Their Own Right ATP, the cell’s primary energy currency.

REACTIONS OF BIOLOGICAL COMPOUNDS HYDROLYSIS REACTIONS –Water is added to break apart molecules C 12 H 22 O 11 + H 2 O C 6 H 12 O 6 + C 6 H 12 O 6 MALTOSE WATER GLUCOSE GLUCOSE

CONDENSATION / DEHYDRATION REACTIONS CONDENSATION REACTIONS (DEHYDRATION SYNTHESIS REACTIONS) –Joining molecules together by removing water (-H and –OH are removed to make a water molecule) C 6 H 12 O 6 + C 6 H 12 O 6 C 12 H 22 O 11 + H 2 O GLUCOSE + GLUCOSE MALTOSE + WATER

CATALYST SPEEDS UP THE NATURAL RATE OF REACTIONS CAN BE ORGANIC OR INORGANIC

ENZYMES A PROTEIN CATALYST THAT CONTROLS THE RATE OF A REACTION

ENZYMES LOWER THE ACTIVATION ENERGY NEEDED TO CARRY OUT A REACTION INCREASES THE RATE OF REACTIONS

ENZYME NAMES END IN –ase NAME IDENTIFIES A REACTING SUBSTANCE –LIPASE – REACTS WITH LIPIDS –SUCRASE – REACTS WITH SUCROSE NAME CAN IDENTIFY FUNCTION –OXIDASE – CATALYZES OXIDATION –HYDROLASE – CATALYZES HYDROLYSIS

SUBSTRATES Substance acted upon by an enzyme

ENZYME ACTION: LOCK & KEY MODEL AN ENZYME BINDS A SUBSTRATE IN A REGION CALLED THE ACTIVE SITE ONLY CERTAIN SUBSTANCES CAN FIT IN THE ACTIVE SITE ENZYME-SUBSTRATE COMPLEX FORMS SUBSTRATE REACTS TO FORM PRODUCT PRODUCT IS RELEASED

LOCK & KEY METHOD ENZYME-SUBSTRATE COMPLEX ACTIVE SITE

ENZYME FUNCTION

FACTORS AFFECTING ENZYME ACTION TEMPERATURE –LITTLE ACTIVITY AT LOW TEMPS –RATE INCREASES WITH TEMPERATURE –MOST ACTIVE TEMP IN HUMANS (37ºC) –ACTIVITY LOST WITH DENATURATION AT HIGH TEMPERATURE

TEMPERATURE AFFECTING ENZYME ACTION RATE OF REACTION TEMPERATURE LOW HIGH OPTIMUM TEMPERATURE

SUBSTRATE CONCENTRATION AFFECTING ENZYME ACTION RATE OF REACTION SUBSTRATE CONCENTRATION LOW HIGH MAXIMUM ACTIVITY

pH AFFECTING ENZYME ACTION RATE OF REACTION pH LOW HIGH OPTIMUM Ph * Most enzymes lose activity in low or high pH