Chapter 2 Section 3

Carbon The main ingredient of organic molecules Life w/o Carbon is as unlikely as life w/o H 2 O Atomic # 6 –6 PROTONS –6 NEUTRONS –6 ELECTRONS CAPABLE OF 4 BONDS

Most carbon based molecules are classified as organic molecules. –Non carbon based molecules are inorganic molecules. Carbon can be bound with other carbons to form carbon “backbones” or “skeletons”

NO, Like This……

Monomers and Polymers Many bio-molecules are made of hundreds of atoms. These large molecules are built of monomers - similar units used to build large molecules. Many monomers linked together are called polymers – long chains of monomers

Life’s Macromolecules Broken down into four categories 1.CARBOHYDRATES 2.LIPIDS 3.PROTEINS 4.NUCLEIC ACIDS

CARBOHYDRATES Carbohydrate – an organic compound made of sugar molecules. –Sugars contain Carbon, Hydrogen, and Oxygen in a 1:2:1 ratio Example Glucose C 6 H 12 O 6 Monosaccharide – simple sugar containing 1sugar unit. –Examples: glucose, fructose, galactose

Glucose is the main fuel supply for cellular work. –Broken down for energy –Carbon skeletons reused to make other kinds of organic molecules. –Glucose not immediately used may be incorporated into larger carbohydrates or used to make fat.

Disaccharides – double sugar. Two monosaccharides bonded together. –Example: Sucrose – carbohydrate found in plant sap, table sugar, maple syrup. Glucose + Fructose Polysaccharides – long polymer chains made up of simple sugar monomers. –Examples: Starch Glycogen Cellulose

STARCH Found in plant cells –Foods high in starch Potatoes Corn Rice Wheat WHO WANTS A CRACKER?

GLYCOGEN Polysaccharide found in animal cells. –Stored in granules in the liver and muscle cells

Cellulose Polysaccharide found in plants –Protects cells –Gives structure –Made of glucose monomers –Commonly referred to as fiber

Cellulose cont. Most animals, including humans, can’t digest cellulose –Keeps digestive tract healthy –Does not act as a nutrient

Cellulose cont. Cows and horses can digest cellulose thanks to microorganisms living in their stomachs or intestines that break it down for them.

Almost all carbohydrates are hydrophilic –Hydrophilic – like water, can be dissolved in water Many monosaccharides and disaccharides dissolve in water Cellulose does not –Too big –If it did we wouldn’t be able to do laundry Cotton T-shirts and jeans would dissolve.

Lipids A class of water avoiding compounds –Hydrophobic This property of lipids is important for their function.

Functions of Lipids Some types can act as boundaries that surround and contain the aqueous contents of cells. Some types can circulate in the blood and act as chemical signals to cells Other types, known as fats, store energy in your body.

Fats Consist of a 3-carbon backbone called glycerol attached to three fatty acids each with long hydrocarbon chains.

Some fats are solid at room temperature. Others called oils are liquids at room temperature. In addition to storing energy, fats cushion organs and provide body with insulation.

Saturated vs Unsaturated Saturated - a fat in which all three fatty acid chains contain the maximum possible # of hydrogen atoms. –All carbons in the chain form single bonds with each other. –The rest of their bonds are with hydrogen atoms

Saturated vs Unsaturated Most animal fats such as lard and butter are saturated fats. Unsaturated – at least one chains contains less than the maximum # of hydrogens.

Saturated vs Unsaturated Diets rich in saturated fats may be unhealthy –May promote buildup of lipid-containing deposits, called plaques, within blood vessel walls. –May reduce blood flow and contribute to heart disease.

Other types of Lipids Waxes Steroids Cholesterol Hormones

Proteins Composed of long chains of amino acids –Amino acids – the building blocks (monomers) of proteins 20 different amino acids Proteins differ only by the # AND arrangement/combination of amino acids Example: –English Alphabet »26 letters combined in various combinations form thousands and thousands of words.

Protein Functions 2 Main Functions –Structural –Enzymes 1.Structural Many proteins form structural molecules Examples: Cartilage & Tendons are made of proteins called collagen. Hair, Feathers, and Parts of cells are all made of proteins.

Protein Functions cont. 2.Enzymes Proteins that increase the rate of chemical reactions taking place in your body. They do this by lowering the amount of energy required to start the reaction PROTEIN STRUCTURE Proteins have a 3D shape that supports their functions. Denaturation: When a protein’s shape is altered to a point that the protein can no longer function properly.

*********YOU NEED TO ADD THIS TO YOUR NOTES PAGE******* Enzymes reduce amount of energy needed for chemical reactions to take place. So what is energy?  The ability to do work.  2 Kinds  Potential (stored energy)  Kinetic (energy of motion)

Nucleic Acids 2 types –DNA  Deoxyribonucleic Acid –RNA  Ribonucleic Acid Nucleic acids are made of nucleotides –Nucleotides - the building blocks (monomers) of nucleic acids.

DNA Double helix –2 interlocking, coil shaped strands Forms units of inheritable information called genes Contains directions for everything that goes on in you.

RNA Single strand made from DNA 3 types Major responsibility is protein synthesis –Making proteins