08/19/10 Figure: 03-15 Title: The Triglyceride Tristearin Caption: This lipid molecule is composed of three stearic fatty acids, stemming rightward from the glycerol OH “heads.” Tristearin is found both in beef fat and in the cocoa butter that helps make up chocolate.
CHAPTER 3 BIOCHEMISTRY
ORGANIC COMPOUNDS <ul><li>COMPOUNDS SYNTHESIZED BY CELLS AND CONTAIN CARBON </li></ul>
FUNCTIONAL GROUPS <ul><li>ATTACHED TO CARBON SKELETON – </li></ul><ul><li>AREA THAT PARTICIPATES IN CHEMICAL REACTIONS </li></ul>
FUNCTIONAL GROUPS Amines -NH2 Amino Act as acids Carboxylic Acids; Fatty acids -COOH Carboxyl Polar; hydrophilic Ketones (when =O occurs in the middle of chain -CO Carbonyl Polar; hydrophilic Alcohols; carbohydrates Aldehydes (when =O end of chain) -OH Hydroxyl FUNCTION NAME OF COMPOUND SYMBOL GROUP
Carbon’s Cool Because carbon contains 4 electrons in its outer shell, it can pair in many ways with many different atoms in an “attempt” to fill its outer shell. Carbon is the central atom of life.
Carbon is the Central Atom of Life. glucose amino acids fat
Some Useful Nomenclature Learn to recognize these chemical groups.
In Biology, Molecular 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 major types of biological molecules.
Molecules of Life Start with water, add lots of small carbon-containing molecules and ……. How do you build a cell? use these four major classes of biological molecules.
MOLECULES OF LIFE <ul><li>CARBOHYDRATES </li></ul><ul><li>LIPIDS </li></ul><ul><li>PROTEINS </li></ul><ul><li>NUCLEIC ACIDS </li></ul>
Monomers, Polymers and Macromolecules Many biological molecules are macromolecules – huge assemblies of atoms. Biological macromolecules are formed by linking together a set of building blocks (monomers ) into long chains (a polymer).
POLYMERS ( LARGE MACROMOLECULES OF 3 TO MILLIONS OF MONOMERS) <ul><li>4 CLASSES </li></ul><ul><li>POLYSACCARIDES </li></ul><ul><li>TRIGLYCERIDES </li></ul><ul><li>POLYPEPTIDES ( PROTEINS) </li></ul><ul><li>NUCLEIC ACIDS </li></ul>
MONOMERS (SUBUNITS OF POLYMERS) <ul><li>MONOSACCARIDES </li></ul><ul><li>GLYCEROL AND FATTY ACIDS </li></ul><ul><li>AMINO ACIDS </li></ul><ul><li>NUCLEOTIDES </li></ul>
FORMATION OF POLYMERS <ul><li>When 2 monomers join a hydroxyl –OH group is removed from one monomer and a –H is removed from other ; water is given off </li></ul><ul><li>CONDENSATION REACTION- water is removed and a bond made </li></ul>
BREAKDOWN OF POLYMERS <ul><li>HYDROLYSIS REACTION-- </li></ul><ul><li>REVERSE OF CONDENSATION RX </li></ul><ul><li>-OH group from water attaches to one monomer and –H attaches to the other </li></ul>
Carbohydrates Carbohydrates are used for energy and to create structures. The building blocks for carbohydrates are simple sugars . ( glucose, fructose Three views of glucose, a common simple sugar.
MONOSACCARIDES <ul><li>1 ) 6 CARBON SUGARS </li></ul><ul><li>GLUCOSE AND FRUCTOSE (C6H12O6) </li></ul><ul><li>Isomers- same formula different arrangement of atoms </li></ul><ul><li>**draw glucose and fructose in notebook using text </li></ul>
<ul><li>2) Ribose and deoxyribose – </li></ul><ul><li>5 carbon sugars important in DNA /RNA </li></ul><ul><li>**draw in notebook </li></ul>
DISACCARIDES <ul><li>CONTAIN 2 MONOSACCARIDES </li></ul><ul><li>LACTOSE = GALACTOSE + GLUCOSE </li></ul><ul><li>( FOUND IN MILK) </li></ul><ul><li>MALTOSE= GLUCOSE + GLUCOSE </li></ul><ul><li>( DIGESTION OF STARCH ) </li></ul>
Linking Simple Sugars – the First Step to a Polymer A complex carbohydrate is a long-chain polymer made of simple sugars. monosaccharides a disaccharide
POLYSACCARIDES <ul><li>CHAINS OF GLUCOSE MOLECULES </li></ul><ul><li>4 OF THEM: </li></ul><ul><li>STARCH </li></ul><ul><li>GLYCOGEN </li></ul><ul><li>CELLULOSE </li></ul><ul><li>CHITIN </li></ul>
Some Familiar and Important Complex Carbohydrates Note the way complex macromolecule are built by linking simple repeating units.
Carbohydrates are Central Players in Energy Production and Storage
Complex Carbohydrates Are Often Used to Create Structures Cellulose is the most abundant macromolecule on earth – and you’re probably wearing it now.
LIPIDS <ul><li>Types: </li></ul><ul><li>Fats, Oils, waxes, phospholipids, steroids </li></ul><ul><li>Hydrophobic </li></ul><ul><li>Composed of monomers called fatty acids </li></ul>
Fats are Used in Energy Storage and Production
The Degree Of Saturation In A Fat Affects Its Physical And Health Properties Where are the double bonds?
Cis and Trans Unsaturated Fats all cis polyunsaturated “ Good” Omega-3-fatty acids mono- and poly-unsaturated saturated trans “ Bad”
At a Store Near You Beginning January 1, 2006, the FDA required that the amount of trans fat be listed on all food labels. The new line showing levels of trans fat
Sterols Sterols are: 1) essential membrane components and 2) form many 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. Phospholipids have a molecular Jekyll and Hyde split personality.
Hydrophilic Head Group And Hydrophobic Tails Are The Keys To Phospholipid Function
Phospholipids Form Double-Layered Biological Membranes
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.
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. Peptide bonds
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 Recently, we’ve learned that RNA also plays important regulatory roles.
Nucleotides Are the Monomers That Create Polymers of DNA and RNA
Nucleotides fuel the cell and coordinate its metabolism. Nucleotides are Important in Their Own Right ATP, the cell’s primary energy currency.