Organic Compounds

Organic Compounds Carbon based molecules 4 Main Groups Carbohydrates Lipids Proteins Nucleic Acids

Carbohydrates C, H, O (ratio of 1:2:1) 4 cal/g Building blocks Monosaccarides 1 carbon ring (hexagon or pentagon) C6H12O6 Glucose Blood sugar Fructose Galactose Deoxyribose (DNA) & Ribose (RNA)

Carbs (cont.) Disaccarides Sucrose Lactose Maltose Glucose + fructose Table sugar Lactose Glucose + Galactose Milk sugar Maltose Glucose & glucose Product of starch digestion, germinating wheat & malt beverages

Carbs (cont.) Polysaccharides Long chains of glucose Glycogen Starch Glucose-storage molecule Made by cells of liver, muscles, brain, uterus & vagina Produced when blood sugar levels are high Used when blood sugar levels are low Starch Energy-storage for plants Store it when sunlight & nutrients are available & use it when low Cellulose Gives strength to cell walls of plants We have no enzymes to digest it Aka dietary fiber – draws water & helps move food through intestines

Conjugated Carbs Glycolipids Glycoproteins Proteoglycans Serve as markers for cell recognition Glycoproteins Major component of mucus Proteoglycans Carbo component is dominant over protein Forms gels that help hold cells together Lubricates joints of skeleton Makes cartilage tough & rubbery

Lipids C,H,O (& sometimes P) – high ratio of H to O 9 cal/g 5 primary types in humans Fatty acids Triglycerides Phospholipids Steroids Eicosanoids

Fatty Acids Chain of ~4-24 C atoms Saturated Unsaturated (with carboxyl on one end & methyl at other) Saturated Unsaturated Polyunsaturated Max H Double bonds between C Many double bonds

Trans Fatty Acids

Triglyceride 3 fatty acids + glycerol (3-C alcohol) Once joined cannot donate H+ Primary function = energy storage Thermal insulation cushioning

Phospholipids 2 fatty acids, glycerol & phosphate group Hydrophilic ( ) head Hydrophobic ( ) tail Make up the cell membrane aka phospholipid bilayer

The Cell Membrane

Steroids 17 C arranged in 4 rings Cholesterol is the “parent” steroid from which all others are made Mostly synthesized by animals 15% from diet 85% made in body Important component of cell membrane Also cortisol, progesterone, estrogens, testosterone, and bile acids

Proteins Proteios “of 1st importance” Building blocks – amino acids Large complex molecules

Proteins (cont.) Peptide Oligopeptides Polypeptides Protein 2 or more amino acids joined by peptide bonds joins amino group w/ other carboxyl group, removing water in the process Oligopeptides 10-15 amino acids (“a few”) e.g. Oxytocin (9) Polypeptides 15+ AA e.g. ATCH (hormone) (39) Protein 50+ AA e.g. Keratin, collagen, actin & myosin, etc.

Protein Structure 1oAmino acid sequence determined by gene (DNA) 2o Hydrogen bonds 3o folding & coiling due to interactions with R groups hydrophilic/hydrophobic regions Much denaturing (unfolding due to pH or temp) occurs here 4o joining of 2+ polypeptide chains

Protein functions Structure Communication Membrane transport Catalysis Keratin –tough, water-proof protein in skin, hair & nails Collagen – durable protein in bone, cartilage and teeth Communication Cell-to-cell via hormones Membrane transport Channels, carriers, Catalysis Enzymes (globular proteins) are responsible for metabolic pathways Recognition & protection Antigens & antibodies Clotting proteins Movement Intracellular transport muscles Cell adhesion Bind cells to each other Keeps tissues together Allows immune cells to bind enemy cancer cells Allows sperm to fertilize the egg