Macromolecules can be classified into four categories: carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates include monosaccharides (single sugars), disaccharides (two bonded sugars), and polysaccharides (many bonded sugars). Lipids are hydrophobic and include fats, phospholipids, and steroids. Proteins are made of polypeptides formed from amino acid subunits and fold into complex shapes that determine their function. Nucleic acids like DNA and RNA store and transmit genetic information through nucleotides containing phosphate, sugar, and nitrogenous base subunits.

1. Macromolecules

2. Macromolecules = big 4 classes Carbohydrates Proteins Nucleic Acids Lipids Polymers

4. A. Carbohydrates Sugars & sugar polymers ~CxH2xOx

5. 1. Monosaccharides Single sugars Major nutrient for cells EX: glucose, fructose, galactose, ribose * deoxyribose Triose sugars(C3H6O3) Pentose sugars(C5H10O5) Hexose sugars(C6H12O6) H H H H O O O O C C C C H C OH H C OH H C OH H C OH H C OH H C OH HO C H HO C H Aldoses H H C OH H C OH HO C H H C OH H C OH H C OH Glyceraldehyde H C OH H C OH H Ribose H H Glucose Galactose H H H H C OH H C OH H C OH C O C O C O HO C H H C OH H C OH H C OH H C OH Ketoses H Dihydroxyacetone H C OH H C OH H C OH H Ribulose H Figure 5.3 Fructose

6. 2. Disaccharides 2 sugars Joined by glycosidic linkage Cov bond formed btwn 2 monosaccharides by dehyd rxn EX: Glucose + glucose = maltose Glucose + fructose = sucrose Glucose + galactose = lactose

7. CH2OH CH2OH CH2OH CH2OH O O O O H H H H H H H H 1–4glycosidiclinkage HOH HOH HOH HOH 4 1 H H H H OH OH O H OH HO HO OH O H H H H OH OH OH OH H2O Glucose Maltose Glucose CH2OH CH2OH CH2OH CH2OH O O O O 1–2glycosidiclinkage H H H H H HOH HOH H 2 1 H OH H HO H HO H HO H O O HO CH2OH CH2OH OH H H OH H H OH OH H2O Glucose Sucrose Fructose

8. 3. Polysaccharides Few 100 to 1000s of monosaccharides joined by glycosidic linkage 2 Functions: Storage Structural Starch – glucose polymer in plants α configuration (helical) Stored as granules in plastids EX: amylose & amylopectin Glycogen – Glucose polymer in animals Extensively branched Stored in liver & muscles of humans Cellulose Glucose polymer in plants β configuration (helical ) Major cmpnt of cw in plants Most abundant org cmpd on E Difficult to digest Req’s symbiotic relationships EX: bact & cows; termites & flagellates Chitin Used for cw of fungi Used for exoskeleton of arthropods

10. 1. Fats Compsd of glycerol & FAs (FA is 16-18 C long HC) Saturated – as many Hs as possible; solid; animal Unsaturated – missing Hs; double bonds; liquid; plant Trans – hydrogenated; added Hs *health probs Function – nrg storage (lt wt – animals mobile)

11. 2. Phospholipds Main cmpnt of cell memb Form bilayer Ambivalent behavior WATER Hydrophilic head WATER Hydrophobic tail

12. 3. Steroids C skeleton consisting of 4 fused rings EX: Cholesterol Common component of animal cell memb Precursor from which other steroids are made Hormones are prod’d from cholesterol H3C CH3 CH3 CH3 CH3 HO

13. C. Proteins 50% dry mass of cells Enzyme = protein that ∆s rate of chem rxn w/o being consumed by rxn Catalyst = enzyme that speeds up rxn Polypeptides = polymer of AAs 20 AAs Protein consists of 1 or + pptds folded & coiled into specific conformations AA monomers are held together by peptide bonds

14. +H3N Amino end Amino acid subunits helix Protein Conformation & Function(Sanger)4 levels: Primary (1°) Sequence of AAs Linear Secondary (2°) H bonds of ppt backbone responsible for: α-helix (H bonds btwn every 4thAA) β-pleated sheet (H bonds btwn parts of a II pptd backbones) Tertiary (3°) Overall shape of pptd due to interxns of side chains H bonds, ionic bonds & disulfide bridges Quanternary(4°) Way 2 or more pptds fold together

15. Changes in Proteins Sickle Cell ∆ in 1 AA valine subbed for normal glutamic acid Denaturation ∆ in protein shape  inactive Can be caused by pH [salt] Temp Denaturation Denatured protein Normal protein Renaturation Figure 5.22

16. 18 X-raydiffraction pattern Photographic film Diffracted X-rays X-ray beam X-raysource Crystal Nucleic acid Protein (b) 3D computer model (a) X-ray diffraction pattern X-ray crystallography Is used to determine a protein’s three-dimensional structure Figure 5.24

17. Store & transmit genetic info Gene = unit of inheritance 2 Types: DNA & RNA Made of repeating subunits: nucleotides Sugar Phosphate Base Nucleoside Nitrogenous base O 5’C O O CH2 P O O Phosphate group 3’C Pentose sugar Figure 5.26 (b) Nucleotide Nucleic Acids