The Chemistry of Biology Macromolecules

CHONPS  Carbon - C  Hydrogen - H  Oxygen - O  Nitrogen - N  Phosphorus - P  Sulfur - S

 Living things require millions of chemical reactions for survival. This is metabolism.  Organic molecules:  In living things.  Always contain CARBON.  Large molecules, many atoms  Always have covalent bonds.

Organic vs. Inorganic  Organic compounds contain Carbon  Everything else = inorganic compounds

Macromolecules  What is a macromolecule?  Macro= Large  Molecule= a group of atoms held together by bonds.

Building large molecules  Chain together smaller molecules  building block molecules = monomers  Big molecules built from little molecules  polymers

Building important polymers sugar – sugar – sugar – sugar – sugar – sugar nucleotide – nucleotide – nucleotide – nucleotide Carbohydrates = built from sugars Proteins = built from amino acids Nucleic acids (DNA) = built from nucleotides amino acid amino acid – amino acid – amino acid – amino acid – amino acid – Fats = built from glycerol and fatty acids One fatty acid Glycerol fatty acid Molecule fatty acid – – –

 Small molecules = building blocks  Bond together = polymers, remove one water for each bond=dehydration synthesis. Building large organic molecules

Breaking apart large molecules  Break bonds by adding water=hydrolysis  Back to single monomers

Carbohydrates  Composed of C,H,O  Usually a 1:2:1 Ratio  Main source of energy  Some plants and animals use carbs for structural purposes

Types of Carbohydrates Single Sugars Monosaccharides  Glucose  Galactose (component of milk)  Fructose (fruits) Double Sugars Disaccharides Glucose + fructose= sucrose Glucose + galactose=lactose

Types of Carbohydrates  Sugars formed from many monosaccharides = polysaccharides

Types of Carbohydrates  Polysaccharides Starches =common storage form of glucose (many glucose molecules)

Types of Carbohydrates  Glycogen = storage of excess sugars in animals.  Stored in liver  When levels of glucose is low in your blood, glycogen is released from your liver to be used in your muscles for muscular contraction and movement.

Types of Carbohydrates  Cellulose  Found in plants. Gives plants their strength and rigidity.  Major component of wood and paper.

Lipids  Molecules that are insoluble in water.  Composed of C,H,O.  Fats, oils, waxes.

Lipids = Major Functions  Used to store energy  Supplies more energy than carbohydrates:  1 g. fat = 9cal  1 g. carb = 4 cal  Structural support in cell membranes.

Saturated Fats  Fats with single bonds on the carbons of a fatty acid chain.  Solid at room temp.  Examples  Butter fats  Meat fats

Unsaturated Fats  One carbon- carbon double bond in the fatty acid chain.  Liquid at room temperature  Examples  oils

Lipids-Steroids  Carbon skeleton with four fused rings.  Hormones like estrogen and testosterone  Cholesterol

Nucleic Acids  Contain C, H,O,N,P (phosphorus)  Nucleic Acids are formed from linking nucleotides  Nucleotides consist of  5-Carbon Sugar  Nitrogen base  Phosphate group

Nucleic Acids Function  Nucleic Acids store and transmit heredity or genetic info.  There are two types:  DNA = Deoxyribonucleic Acid  RNA = Ribonucleic Acid

Proteins  Contain Nitrogen (N) as well as C,H,O.  Proteins are made up from AMINO ACIDS.  The polypeptide chain made by linking amino acids.  Each protein has a very specific order and number of amino acids.  There are 20 different amino acids. The 20 amino acids are on the next slide-do not copy them down.

Functions of Proteins  Form bones and muscles and other structures in body like hair  Provide nutrient storage  Transporters for substances in and out of cells.  Defend the body.

Functions of Proteins Continued  Assist in chemical reactions within cells- called enzymes.  Act as catalysts, lowering activation energy needed for reactions-speed up reaction.

Proteins-shape  Proteins have a very specific structure and shape- conformation.  Primary structure -chain of amino acids.  Secondary - coiled/folded chain held by bonds.  Tertiary -the 3D globular shape held by bonds.  Quaternary -subunits held together.

Proteins-denature  Changes in environment can cause a protein chain to unravel, losing its shape- denature.  Causes-change in salt concentration, pH, temperature.  Egg white room temp→→egg white heated.

Macromolecules Lab Notes  Indicators = chemicals that detect the presence of organic molecules by changing colors  Color change is completely brand new

Indicators  Fehlings A and B detect sugars  Iodine detects starch  Biuret detects protein  Paper towel detects lipids Part I – determine how to identify known macromolecules using chemical indicators – What color change do you see?