Introduction to Biology – Part 2 The Molecules of Life (pp. 44-47)

1. Introduction to Biology – Part 2The Molecules of Life (pp. 44-47) I. Importance of Carbon Test: 9/13 Although a cell is composed of70 - 95%water, most of the rest is carbon – based compounds. A. Structure of carbon 1. Atom # 6:6protons &6electrons:2in the first shell &4 in the second. 2. Has 4 valence electrons – so it can make four covalent bonds 3. Usually bonds with:hydrogen, oxygen, phosphorus, sulfur, and nitrogen 4. Can also bond w/othercarbonatoms 5. Compounds with carbon-carbon bonds called organic

2. B. Macromolecules – macro =large, so these are very largemolecules 1. Polymers a. Poly =many b. These are large molecules made up of similar or identical building blocks 2. Monomers a. Mono =one b. Are the building blocks orsubunit of polymers

3. 3. Classes of macromolecules are also called Biomolecules a.Carbohydrates b.Lipids c.Nucleic acids d.Proteins

4. II. Carbohydrates A. Elements:C, H, O, always a1:2:1ratio of H atoms to O atoms (2H:1O) B. Monomer: monosaccharide C. Function: immediate and storedenergy; building material D. Where found in body: bloodstream, liver; cell walls of plants E. Food source: sugar and starches

5. F. Examples: 1. Monosaccharides: (simplesugar) a. Glucose (C6H12O6) – preferred energy molecule for most organisms; including humans b. Galactose – one component of milk c. Fructose – found in some fruits 2. Disaccharides:2monosaccharides bonded together a. Sucrose –tablesugar: glucose + fructose b. Lactose –milksugar: glucose + galactose

6. 3. Polysaccharides:more than 2 monosaccharides bonded together; two groups a. Storage Polysaccharides: long polymers of glucose; broken down for needed energy • Glycogen Storage of glucose inanimals Stored inlivers and muscles • Starch Storage of glucose inplants Humanscanbreak down glucose for energy

7. b. Structural Polysaccharides: used for building materials • Cellulose Component ofplantcell walls Humansunableto break down Important source offiberin our food • Chitin Component offungicell walls Component of insect and other arthropod exoskeleton

8. III. Lipids: (waxy, fatty or oily) compounds A. Elements: C, H, O, many more H than in carbs. B. Monomer: glycerol & fatty acids C. Function: energy storage;insulation; cushioning D. Where found in body: cell membrane, innermost layer of skin, surrounding some organs E. Food Source:olive oil, corn oil, sesame oil, peanut oil, canola oil F. Example: 1. Fats and Oils a. All have 3 fatty acids b. Fatsare solidat room temperature c. Oilsare liquidat room temperature d.Saturatedfats – no carbon – carbon double bond e.Unsaturatedfats – at least one carbon – carbon double bond f.Saturatedfats linked to heart disease

9. 2. Phospholipids a. Unique lipid b. Found in every living cell membrane 3. Steroids a. Used for hormone production b. Used for animal cell structure c. Example: cholesterol, testosterone

10. IV. Proteins A. Elements:C, H, O, P, N B. Monomer: amino acids, only 20 different amino acids combine in different numbers, patterns & arrangement C. Function: support, structure,protection, movement, metabolism D. Where found in body: muscle, hair, skin, enzyme E. Food Source:meat, beans, eggs, dairy products F. Examples: 1. Enzymes a.Biological catalyst b. Trigger chemical reactions c. Could not maintain homeostasiswithout them

11. V. Nucleic Acids A. Elements:C, H, O, P B. Monomer:nucleotides C. Function: genetic instructions & usable energy D. Where found in body: nucleus of cells E. Food Source:none F. Examples: 1. DNA a. Deoxyribonucleic acid b. Contains thegenetic instructions for the cell 2. RNA a. Ribonucleic acid b.Carries outthe instructions in DNA 3. ATP a. Adenosine triphosphate b. Producesuseable energy for the cell