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Water, pH and Biological Molecules. 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 as a Solvent. Dissolving table salt (sodium chloride).
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Water, pH and Biological Molecules 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 as a Solvent Dissolving table salt (sodium chloride)
Water Is Lighter as Solid than as a Liquid This means that ice forms an insulating blanket over water.
Water Has High Surface Tension The attraction of one water molecule for another also accounts for its ability to hold huge amounts of heat.
p+ 1H 1H p+ Water is a Polar Compound • Hydrogen ends holds slightly positive charges • Oxygen end holds a slightly negative charge (+) (+) (--)
pH is a Big Deal pH is a measure of proton (hydrogen ion or H+) concentration. Low pH (acid) = lots of H+ ions High pH (base) = few H+ ions ; more OH- ions
Acid = H+ Donors Base = H+ Acceptors Acids and Bases
ORGANIC COMPOUNDS Organic compounds are carbon compounds, made by living things 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.
glucose amino acids fat Carbon is the Central Atom of Life.
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 Four Major Classes of Biological Molecules How do you build a cell? Start with water, add lots of small carbon-containing molecules and …….
Rules of the Game Macromolecules are built by linking a set of building blocks (monomers) together into long chains (a polymer). Monomers – basic units that repeats over and over in organic compounds Each hexagon is this figure is a monomer, building blocks linked together to form a polymer.
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 MONOSACCHARIDES DISACCHARIDES
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 FA Glycerol FA FA
Sterol Phospholipid Fat Lipids are Hydrophobic Molecules That Exist In Three Primary Forms
Space-filling model of a fat A fatty acid Fats Are Made By Linking Fatty Acid Chains to Glycerol, a Three Carbon Molecule
Where are the double bonds? The Degree Of Saturation In A Fat Affects Its Physical And Nutritional Properties
saturated monounsaturated Where are the double bonds? polyunsaturated The Degree Of Saturation In A Fat Affects Its Physical And Nutritional Properties
Note the four ring structure common to all sterols. Sterols Are Part of Cellular Membranes and Act as Hormones
Sterols As Hormones Estrogen, testosterone, progesterone, and corticosteriods (cortisol) are all steroid hormones.
A heavily muscled Linford Christie who was disqualified from international competition after testing positive for a banned steroid. 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.
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.
Proteins are Linear Chains of Linked Amino Acids
A Common Thread and a Unique Identity (Side chain) R – Residual Group *side chain changes Amino Group – NH2 Single Hydrogen - H Acid or Carboxyl Group –C=O, OH
Peptide bonds 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 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)
ATP, the cell’s primary energy currency. Nucleotides are Important in Their Own Right Nucleotides fuel the cell and coordinate its metabolism.
ASSEMBLING MACROMOLECULES AND BREAKING THEM DOWN
REACTIONS OF BIOLOGICAL COMPOUNDS • HYDROLYSIS REACTIONS • Water is added to break apart molecules • C12H22O11 + H2O C6H12O6 + C6H12O6 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) • C6H12O6 + C6H12O6 C12H22O11 + H2O GLUCOSE + GLUCOSE MALTOSE + WATER