The Chemistry of Life

Ms. Sanford & Mr. O’ConnorJefferson High SchoolNovember 11, 2008

Organic Chemistry• the study of all compounds that contain

bonds between carbon atoms• What makes Carbon so important?• can bond with many elements

– Hydrogen– Oxygen– Phosphorus– Sulfur – Nitrogen

• can bond with other carbon atoms– form chains, almost unlimited in length

Carbon• carbon-carbon bonds (covalent) can be single,

double, or triple• ability to form millions of different large and

complex structures

H

H C H

H

H C C H

H H H H

C C C C

H H

H

H C H

C C

C C

H C H

H

Macromolecules• “giant molecules”

• made from thousands or hundreds of thousands of smaller molecules– formed by polymerization

– joining together of small compounds• monomers polymers

• monomers may be identical or different

monomers

polymer

Organic Compounds• Carbohydrates– made of carbon (C), hydrogen (H), & oxygen

(O)– 1 : 2 : 1 ratio (CH2O)

• Lipids– made of C, H, & O– ↑ 2 : 1 ratio (H : O)

• Proteins– made of C, H, O, & N

Carbohydrates

• Also called sugars• Energy source• Important in building other molecules

• Three Types:– monosaccharides– disaccharides– polysaccharides

Monosaccharide• “simple sugars”• 3 – 7 carbons in chain• Glucose

– most abundant sugar on planet– product of photosynthesis– principle sugar in human blood– approx. 5 g (enough for 15 min. of energy)

• Galactose– Milk sugar

• Fructose– Fruit sugar– Twice as sweet as table sugar

• Glucose, galactose, & fructose are all C6H12O6

– Isomers (different 3-D forms)

Disaccharides• two simple sugars bonded together• produced through dehydration synthesis

– removal of water molecule

• Maltose – glucose + glucose

• Sucrose – glucose + fructose

• Lactose – glucose + galactose

• broken down by hydrolysis– addition of water molecule

Polysaccharides• Complex carbohydrates• “poly” means many• Simple sugars joined into long chains• Play great roles in Biology

Polysaccharides Continued…

• Starch– storage product of plants– 100’s of glucose units– branched and unbranched

• Glycogen– carbohydrate storage in animals– similar to plant starch by more branching– continuous source of energy– any simple sugar not used or stored as glycogen

becomes fat

• Cellulose– highly insoluble form of polysaccharide– used for structural support in plants

Lipids• Organic form of stored energy• Used as energy, after carbohydrates• Include:

– Fats– Oils– Waxes

• Three fatty acid molecules and one glycerol– Dehydration synthesis – gives off 3 water molecules

• Fat should be 20 – 35% of calories you consume• Three Types: (each should be 1/3 of fat intake)

– Saturated– Monounsaturated– Polyunsaturated

Saturated1) solid at room temperature2) raises blood cholesterol3) sources animal products

– lard– butter– cheese– meat

• Single bonds that join two carbon atoms

Unsaturated• Monounsaturated

1) little effect on blood cholesterol but provides a concentrated source of calories

2) olives, olive oil, peanuts, peanut butter, peanut oil, avocados, pecans, and almonds

• Polyunsaturated1) low in cholesterol and liquid at room temperature2) vegetable oils such as cotton seed, sunflowers, sesame

and soybean

•Double bonds join two or more carbon atoms

Proteins & Amino Acids

• Macromolecules• in charge of growth and repair of cells• 15% of the mass of the average person• made up of amino acids (50 – 2,000)– use only essential amino acids– basic chemical building blocks• amino means there is an NH2 group• a carboxyl group is made up of 1-(C), 2-(O), 1-(H)

acidic– 50 amino acids 20 are Essential (for life to exist)• build all proteins needed for life

– used in every cell of your body

More Amino Acids• How are they

different?– Different side groups– Three groups:

• Ionic• Polar• Non-polar

• Join together to make a chain

Proteins Continued…

• Where are proteins made?– in the ribosomes– dehydration synthesis makes proteins– amino acids form dipeptides

– many dipeptides/polypeptides form proteins

– different orders protein type– highly folded and all twisted around like a knot

di + di + di = poly

poly + poly = protein

Where can Proteins be found?• Muscle, cartilage, ligaments, skin, and hair• Hemoglobin, hormones (insulin) antibodies, and

enzymes• Sources:– Beef– Poultry– Fish– Eggs– Dairy products– Nuts– Seeds– Legumes (beans, peas, lentils)