Chapter 3 notes. BIO.pdf

Carbon − Carbon mainly bonded to o Carbon o O, N, S, P, or H − Can form 4 covalent bonds − Hydrocarbons o Only has carbon and hydrogen − Nonpolar Functional Groups − Molecular groups binding to carbon-hydrogen cores − Each group has unique chem proper...

Carbon − Carbon mainly bonded to o Carbon o O, N, S, P, or H − Can form 4 covalent bonds − Hydrocarbons o Only has carbon and hydrogen − Nonpolar Functional Groups − Molecular groups binding to carbon-hydrogen cores − Each group has unique chem properties − Stay to where they attach and change reactions − Ex. o Hydroxyl Group (-OH) o Carbonyl Group (C=O) o Carboxyl Group (-COOH) o Amino Group (-NH₂) o Ester Group (-COO-) o Phosphate Group (-PO₄³⁻) Isomers − Molecules with same formula different formation − Structural isomers o Different carbon skeleton − Stereoisomers o Differ in how groups attached − Enantiomers o Chiral = four unique groups attached o Mirror image molecules o Ex. ▪ D-Sugars and L-amino acids  ▪ Macromolecules − Polymer – built by monomers − Monomer – small subunits − Ex. o Carbs o Nucleic acids o Proteins o Lipids Assembly and disassembly of polymers − Dehydration synthesis o Large molecules form by H2O leaving o Monomers join to form polymers − Hydrolysis o Break down molecules with water added o Polymer into monomers Carbohydrates − 1:2:1 of carbon, hydrogen, and oxygen − CH2O − C----H covalent bonds hold much energy − Energy storage molecules − Ex. Sugars, starches, glucose Monosaccharides − Simplest carb − Sugars with 6 carbons play vital role  − Glucose C6H12O6 − Fructose is isomer of glucose − Galactose is stereoisomer of glucose − − Different configurations of glucose o − Isomers of glucose o Disaccharides (1 of 2)  − Two monosaccharides bonded by dehydration synthesis − Used for energy storage or sugar transport − Ex. o Sucrose o Lactose o Maltose Polysaccharides − Long monosaccharide chains o Linked through dehydration − Energy storage o Plants use starch o Animals use glycogen − Structural support o Plants use cellulose o Fungi uses chitin Starch and glycogen are polysaccharides − Cellulose is a polysaccharide in plants  − Nucleic acids − Polymer o Nucleic acids − Monomer o Nucleotides − Sugar + phosphate + Nitrogenous base o Sugar is D in DNA or R in RNA − Nitrogenous bases o Purines ▪ Adenine ▪ Guanine o Pyrimidines ▪ Thymine ▪ Cytosine ▪ Uracil Nucleotide structure  − DNA − Encodes info for amino acid sequence or protein − Sequence of bases − Double helix o Two polynucleotide stands connected by hydrogen bonds − Base pairing rules o A + T (or U in RNA) o C+G Structure of DNA  − RNA − Same with DNA except nucleotides − Ribose instead of deoxyribose − Uracil instead of thymine − Used info in DNA to specify sequence of aminos in protein DNA vs. RNA  − Disaccharides (2 of 2) − Adenosine triphosphate (ATP) o Energy currency of cell − Nicotinamide adenine o NAD+ o FAD+ − Carry electrons Proteins (1 of 2) − Enzyme catalysts − Defense − Transport − Motion  − Support − Regulation − Storage Proteins (2 of 2) − It’s a polymer o One or more unbranched chains o Each chain is polypeptide − Amino acids are monomers − Amino acid structure: o Central carbon group o Amino group o Carboxyl group o Single hydrogen o Variable R group Peptide bond − Amino acids joined together o Dehydration synthesis − Formed by end of amino acid and carboxyl end o Four Levels of Structure − The shape of protein determines function 1. Primary structure - Sequence of aminos 2. Secondary structure – group interaction in peptide backbone ▪ Helix = coiled spiral/tubular ▪ Sheet = planar structure/flat 3. Tertiary structure = final folded shape ▪ Stabilized by many forces ▪ Final protein level making polypeptide chain 4. Quaternary structure ▪ Arrangement of subunits in a protein ▪ Two or more polypeptide chains − Additional Structural Characteristics − Motifs o Elements of secondary structure seen in polypeptides o Helps knowing function of unknown protein − Domains o Functional units in in bigger structure o Most protein made of many domains ▪ Perform different parts of protein function  − Chaperones − Thought new protein folded over and over − Help proteins fold right − Deficiencies in chaperone protein cause certain diseases o Cystic fibrosis (hereditary) ▪ Correct amino sequence, fails to fold Denaturation − Protein loses structure and function − Due to environmental conditions o pH o Temp o Ionic concentration of solution − Folded to unfolded protein = denaturation Lipids − Loosely defined molecules o Insoluble in water − High number of nonpolar C---H bonds o Causes hydrophobia − Fats, oils, waxes, some vitamins Fats − Triglycerides o One glycerol, three fatty acids − Fatty acids o Not needed to be identical o Chain length varies o Saturated- No double bonds between carbon atoms ▪ Higher melting point, from animals o Unsaturated – one or more double bonds ▪ Low melting point, from plants o Trans fats are man made ▪ Blasted with hydrogen Phospholipids − Composed of o Glycerol o 2 fatty acids – nonpolar tail o A phosphate group – polar head − Form all biological membranes Micelles − Lipid molecules − Head toward water and tail away o Phospholipid bilayer − Two layers form − Heads go outward − Tails go inward