BIO 151 1st EditionExam # 1 Study GuideMolecules of life1. Life originated and evolved in aqueous environmentsa. depends on solution based chemistry2. Compounds used to build structures in living systems are carbon based (organic compounds)A. Elements: CHOPNS● C, O, H, N make up 96% of all living organisms by mass● C,H,O,P,N, and S make up all macromoleculesB. Chemical bonds/interactions-types and relative strength, polar vs. non-polar C. ● Covalent bonds (strongest): 2 atoms share e-○ Non-polar: electrons are shared equally○ Polar: electrons are shared unequally; have partial charge, more electronegative, more partial negative charge● Ionic bond: electrons striped from one atom to another; move from less EN to more EN; charge-charge interactions● Hydrogen bond: partial charges allow water to associate with neighbors● Van der Waals: microfluctuations that interact○ hydrophobic interactions ei. salad dressingProperties of water, hydrophilic vs. hydrophobic● Cohesion: tendency of H2O molecules to stick together○ water can move to the top of a tree● High specific heat: takes great deal of heat to change temperature of 1g H2O by 1degreeC ○ bodies of water can act as temperature buffers● H20 (s) is more dense than H2O (l): H2O(s) is locked into a lattice with exactly 4 neighbors making it less dense (more spread out)○ ice floats● Very good solvent: ○ Hydrophilic: loves water, charged, partially charged, interact readily with water■ dissolve into H2O■ ionic, polar (rich in EN: O, N) → -OH, -NH○ Hydrophobic: hates H2O, ■ nonpolar bonds: -CHD. Macromolecules: large molecules that are combinations of small, organic moleculesCondensation (dehydration) reactions: water is the product, makes polymersHydrolysis Rxn: breaks down H2O (water=reactant) to break down a polymer; makes monomers1. Carbohydrates (Polysaccharides → polymers of sugars): a. Functional group: carbonyl and hydroxyl i. Polar, hydrophilicb. Diversity in function and behavior comes from:i. Linkages and extent of branching1. ei. Starch vs. Cellulose: a. Starch in alpha form→ linear, easily digested, exposes -OHfunctional groupsb. Cellulose in beta form; flipped→ made in ribbons, rigid linear→ hard for organisms to digest → used for structure instead of food2. Chitin: polymer of N-containing sugars→ used to make exoskeletons of insectsii. Roles for Carbohydrates:1. Structural: Cellulose (plants); Chitin (fungi, animals)2. Energy: starch, glycogenc. Sugar names (for monomers)i. end in -oseii. 5C: ribose, deoxyriboseiii. 6C: glucose, fructose, galactose2. Lipids (glycerol and fatty acids):a. Functional groups: carboxylb. To make lipid: glycerol backbone, fatty acid (non polar) → react together in a dehydration rxn → polarc. Forms of lipids: i. Fats: glycerol + 3 fatty acids = triacylglycerol→ incredibly hydrophobicii. Phospholipids: 2 fatty acids + glycerol + phosphate; hydrophilic → polar1. dual nature: hydrophilic head, hydrophobic tail2. Micelle: self assembles, no energy, spontaneous, heads out, tails in 3. Proteins (Polymer of Amino Acids): a. Functional group: carboxylic acid, amine (positive charge), Ri. R=Variance group: rings (nonpolar bc e- sharing), 20 possible, can be polar, nonpolar, charged, or acidic/basicb. Polymers are formed by dehydrationi. Peptide bond: covalent bond that connects amino acids making a protein via dehydration reactionc. Levels of protein structure:i. Primary Structure: sequence of amino acids connected by peptide bonds, which are covalent bonds; linear chain of amino acidsii. Secondary structure: interactions between amino acids close by; result of hydrogen bonds between constituents of the polypeptide backbone; regions stabilized by hydrogen bonds between atoms of the polypeptide backbone1. Alpha helix: coil held together by H-bonding between every 4th amino acid2. Beta pleated sheet: 2+ segments of the polypeptide chain; parallel H bondsiii. Tertiary Structure: overall shape alpha and beta assume; results from interactions between side chain (R groups) of amino acids; includes hydrophobic, van der waals, ionic bonds, Disulfide Bridge: covalent 2 -SHgroups brought together to make S-S; 3D shape stabilized by interactions between side chainsiv. Quaternary structure: overall protein structure that results from aggregation of peptide subunits; includes interactions between individual protein; association of two or more polpeptidesd. Denatured protein→(high temp, salt, pH extremes) garbage → Renaturation possible4. Nucleic Acids (nucleotides)a. important polymers: RNA and DNAb. subunits: monomers called nucleotides which have 3 parts:i. phosphate groups (1-3)ii. pentose (5C) sugars (ribose or deoxyribose)iii. nitrogenous base (4 in RNA, 4 in DNA)Major types and subunitsFunctional groups and chemical propertiesMembrane structure and functionOrder of life depends on:1. physical boundary (membrane)2. information3. work (energy)A. Introduction: The Cell Theory of Life: 1) life is the functional unit of life, all living organisms are composed of one or more cells2) cells arise only from preexisting cells by dividingB. Components1. Major components (95%): phospholipids, proteins (integral and peripheral)2. Associated protein(5%): glycoproteins/glycolipids (sugar tags ei. blood type), sterols (cholesterol is only in animal cells, but plant cells have other sterols)a. cholesterol is very hydrophobic→ important in membrane functionC. Membrane fluidity: depends on lipid structure, phospholipids aren’t bonded, so they can move all over since there is no restriction on movement● Saturated fats: free rotation● Unsaturated fats: restrict rotation● Polyunsaturated: many double onds● Strategies organisms use to increase fluidity when temperature decreases○ Increase degree of unsaturation in lipids■ increase number of unsaturated (double) bonds in fatty acids■ increase number of fatty acids with unsaturated bonds■ as temperature drops, less packed with phospholipids→ less dense, but maintained fluidity through kinked structure○ Increase cholesterol content of membrane since cholesterol is a fluidity buffer■ cholesterol is bulky, hydrophobic (mostly unpolar) → acts like the kinky unsaturated lipid, makes membrane more fluid at low temp■ motion of lipids will speed up at high temperature, making lipids move way too fast, but cholesterol will calm the lipids down to prevent too muchdisorganization■ With