1 Chemistry of Life

2 Water About percent of an organism is water Water is used in most reactions in the body Water is called the universal solvent Water properties: –Polarity –Cohesivness –Adhesivness –Surface Tension

3 Organic Compounds Compounds CARBONorganicCompounds that contain CARBON are called organic.

4 Carbon (C) Carbon4 electronsCarbon has 4 electrons in it’s outer shell. Carboncovalent bonds 4Carbon can form covalent bonds with as many as 4 other atoms (elements). C, H, O or NUsually with C, H, O or N. Example:CH 4 (methane)Example:CH 4 (methane)

5 Macromolecules Large organic molecules.Large organic molecules. POLYMERSAlso called POLYMERS. MONOMERSMade up of smaller “building blocks” called MONOMERS. Examples:Examples: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic acids (DNA and RNA)

6 Question: How Are Macromolecules Formed?

7 Answer: Dehydration Synthesis “condensation reaction”Also called “condensation reaction” polymers monomers“removing water”Forms polymers by combining monomers by “removing water”. HOH HH H2OH2O

8 Question: How are Macromolecules separated or digested?

9 Answer: Hydrolysis monomers“adding water”Separates monomers by “adding water” HO HH H H2OH2O

10 Carbohydrates

11 Carbohydrates Small sugar moleculeslarge sugar moleculesSmall sugar molecules to large sugar molecules. Americans consume an average of 140 pounds of sugar per person per yearAmericans consume an average of 140 pounds of sugar per person per year Examples:Examples: A.monosaccharide B.disaccharide C.polysaccharide

12 Carbohydrates Monosaccharide: one sugar unit Examples:glucose ( Examples:glucose (C 6 H 12 O 6 )deoxyriboseriboseFructoseGalactose glucose

13 Carbohydrates Disaccharide: two sugar unit Examples: –Sucrose (glucose+fructose) –Lactose (glucose+galactose) –Maltose (glucose+glucose) glucoseglucose

14 Carbohydrates Polysaccharide: many sugar units Examples:starch (bread, potatoes) glycogen (beef muscle) cellulose (lettuce, corn) glucoseglucose glucoseglucose glucoseglucose glucoseglucose cellulose

15 Cellulose CelluloseCellulose is not a nutrient for humans, but it is an important part of a healthful diet Most fresh fruits, vegetables, and whole grains are rich in cellulose microbesSome microbes can break down cellulose into glucose monomers Cellulose, found in plant cell walls, is the most abundant organic compound on EarthCellulose, found in plant cell walls, is the most abundant organic compound on Earth

16 Cows harbor cellulose-digesting bacteria in their stomach to hydrolyze the cellulose of hay and grass to convert the glucose to other nutrients that nourish the cowCows harbor cellulose-digesting bacteria in their stomach to hydrolyze the cellulose of hay and grass to convert the glucose to other nutrients that nourish the cow Termites also have cellulose digesting microbes within their gut because they are unable to digest it by themselves.Termites also have cellulose digesting microbes within their gut because they are unable to digest it by themselves. Some fungi can also digest cellulose, helping recycle chemical elements within the Earth’s ecosystemSome fungi can also digest cellulose, helping recycle chemical elements within the Earth’s ecosystem

17 Lipids

18Lipids not soluble in waterGeneral term for compounds which are not soluble in water. are soluble in hydrophobic solventsLipids are soluble in hydrophobic solvents. Remember:“stores the most energy”Remember: “stores the most energy” Examples:1. FatsExamples:1. Fats 2. Phospholipids 3. Oils 4. Waxes 5. Steroid hormones 6. Triglycerides

19 Lipids Six functions of lipids: 1.Long term energy storage 2.Protection against heat loss (insulation) 3.Protection against physical shock 4.Protection against water loss 5.Chemical messengers (hormones) 6.Major component of membranes (phospholipids)

20 Lipids Triglycerides: c1 glycerol3 fatty acids Triglycerides: composed of 1 glycerol and 3 fatty acids. H H-C----O H glycerol O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = fatty acids O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = O C-CH 2 -CH 2 -CH 2 -CH =CH-CH 2 -CH 2 -CH 2 -CH 2 -CH 3 =

21 Fatty Acids fatty acids There are two kinds of fatty acids you may see on food labels: 1.Saturated fatty acids: no double bonds (bad) 2.Unsaturated fatty acids: double bonds (good) O C-CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 2 -CH 3 = saturated O C-CH 2 -CH 2 -CH 2 -CH =CH-CH 2 -CH 2 -CH 2 -CH 2 - CH 3 = unsaturated

22 Proteins

23 Proteins (Polypeptides) peptide bonds polypeptidesAmino acids (20 different kinds of aa) are bonded together by peptide bonds (polypeptides). Six functions of proteins:Six functions of proteins: 1.Storage:albumin (egg white) 2.Transport: hemoglobin 3.Regulatory:hormones 4.Movement:muscles 5.Structural:membranes, hair, nails 6.Enzymes:cellular reactions

24 Proteins (Polypeptides) Four levels of protein structure: A.Primary Structure B.Secondary Structure C.Tertiary Structure D.Quaternary Structure

25 Primary Structure peptide bonds (straight chains) Amino acids bonded together by peptide bonds (straight chains) aa1aa2aa3aa4aa5aa6 Peptide Bonds Amino Acids (aa)

26 Secondary Structure primary structurecoilspleats hydrogen bonds3-dimensional folding arrangement of a primary structure into coils and pleats held together by hydrogen bonds. Two examples:Two examples: Alpha Helix Beta Pleated Sheet Hydrogen Bonds

27 Tertiary Structure Secondary structure isbentfolded more complex 3-D arrangementSecondary structure is bent and folded into a more complex 3-D arrangement of linked polypeptides Bonds: H-bonds, ionic, disulfide bridges (S-S)Bonds: H-bonds, ionic, disulfide bridges (S-S) “subunit”.Call a “subunit”. Alpha Helix Beta Pleated Sheet

28 Quaternary Structure Composed of 2 or more “subunits” Globular in shape Form in Aqueous environments enzymes (hemoglobin)Example: enzymes (hemoglobin) subunits

29 Nucleic Acids

30 Nucleic acids Two types:Two types: a. Deoxyribonucleic acid (DNA- double helix) b. Ribonucleic acid (RNA-single strand) b. Ribonucleic acid (RNA-single strand) Nucleic acids nucleotidesdehydration synthesisNucleic acids are composed of long chains of nucleotides linked by dehydration synthesis. A typical cell in your body has about 2 meters of DNAA typical cell in your body has about 2 meters of DNA

31 Nucleic acids Nucleotides include:Nucleotides include: phosphate group pentose sugar (5-carbon) nitrogenous bases: adenine (A) thymine (T) DNA only uracil (U) RNA only cytosine (C) guanine (G)

32 Nucleotide O O=P-O OPhosphate Group Group N Nitrogenous base (A, G, C, or T) (A, G, C, or T) CH2 O C1C1 C4C4 C3C3 C2C2 5 Sugar Sugar(deoxyribose)

33 DNA - double helix P P P O O O P P P O O O G C TA