BIOL 118 1st Edition Final Exam Study Guide Biology Tree of Life Characteristics of Living Things o Use energy o Made up of cells o Process hereditary information has genes o Capable of reproduction o Must evolve Cell Theory o All cells are made of cells o All cells come from preexisting cells Theory of Evolution o All species related by common ancestry o Characteristics can be modified from generation to generation Water Carbon Orbitals Specific regions where electrons can move around nuclei each one can hold up to 2 Electron Shells Levels that group orbitals smaller the number the closer to the nucleus Valence Electrons Electrons in the outermost shell Valence Number of unpaired electrons in an atom not the same as valence electrons Ionic Bonds Electrons are transferred to one another Covalent Bonds Atoms share electrons in order to fill their orbitals o Nonpolar Covalent bond Electrons are shared symmetrically o Polar Covalent bond Electrons are shared asymmetrically Water is a prime example Molecules Substances held together by covalent bonds Electronegativity ability of an atom to attract an electron how tightly an electron can be held o An atom with higher electronegativity holds electrons more tightly have a partial negative charge and vice versa Lecture 3 Ion An atom or molecule that carries a charge o Cation An atom that lose an electron and becomes positively charged o Anion An atom that gains an electron and becomes negatively charged Ionic bond Attraction that occur between oppositely charged ions Water Water is a good solvent because its polarity Hydrogen bond weak electrical attractions between partially negative oxygen of one water molecule and partially positive hydrogen of a different water molecule Hydrophilic Ions and polar molecules that stay in solution because of their interactions with water s partial charges Hydrophobic Uncharged and nonpolar compounds that do not dissolve in water Water has certain properties due to its hydrogen bonds o Cohesive Stays together water becomes a droplet instead of spreading out surface tension o Adhesive Adheres to surfaces that have any polar or charged components water sticks to side of beaker o Denser as solid than liquid more molecules in volume of liquid than in same volume of ice o High specific heat energy required to raise the temperature of 1g of substance by 1 degree Celsius Functional Groups Amino N H2 o Amines o Act as a base attracts proton Carboxyl C O OH o Carboxylic acids o Acts as acid drops proton Carbonyl o Aldehydes C OH o Ketones C O o Link molecules into larger complex compounds Hydroxyl OH o Polar group o Act as weak acids Phosphate O3 P O o Have 2 negative charges Sulfhydryl SH o Thiols o Link together via Disulfide bonds Lecture 4 Amino acids are only different in their unique R group Side chains Backbone the other part of the amino acid is the same for all amino acids Hydroxyl amino carboxyl or sulfhydryl side chains have higher chemical reactivity Primary Structure o Unique sequence of amino acids o Single change can radically alter protein function Secondary Structure o Formed by hydrogen bonds between carbonyl amino group o Must bend to allow this forming alpha helices or beta pleated sheets o Large number of hydrogen bonds increase stability Tertiary Structure o Results from interactions between R groups cause the backbone to fold Hydrogen bonds Hydrophobic interactions Van der Waals interactions Covalent Disulfide bonds Ionic bonds o Multi helices Quaternary Structure o Combination of multiple polypeptides into a single structure needs two or more subunits Hydrolysis Break down polymers by adding water Condensation Reaction polymerize monomers by taking out water Denatured An unfolded protein that cannot function normally due to high temps or exposure to acid Molecular chaperones Proteins that help proteins fold correctly in cells Prions improperly folded forms of normal proteins o Can be infectious DNA RNA Nucleotide Building blocks of DNA RNA o Phosphate group joins to sugar by phosphodiester linkage o 5 Carbon sugar DNA deoxyribonucleic acid RNA ribose o Nitrogenous Base DNA A T G C RNA A U G C DNA s secondary structure consists of 2 antiparallel strands twisted into double helix o Stabilized by interior hydrophobic interaction hydrogen bonding between base pairs Replication steps Strand separation unzipping Base pairing polymerization DNA is a poor catalyst How RNA is different from DNA o Contains ribose o Contains uracil o Single stranded o Complex structure like proteins Glycosidic Linkage covalent interaction resulting from condensation reaction between 2 hydroxyl groups o Alpha The orientation is lower o Beta The orientation is higher Types of Polysaccharides Starch o Plants use this to store sugar o Mixture of branched and unbranched alpha glucose polymer Cellulose o Structural polymer found in plant cell walls o Polymer of beta glucose monomers Glycogen o Animals use this to store sugar o Highly branched alpha glucose polymer Lecture 5 Lipid carbon containing compounds that are found in organisms and are largely nonpolar hydrophobic defined by solubility properties Hydrocarbons most commonly known nonpolar lipid molecule that contain only carbon hydrogen lipids do not dissolve in water because hydrocarbon is bonded to a carboxyl group Plasma Membrane separates cell interior from external environment made of phospholipid bilayer Fats Oils o Triglycerides made up of 3 fatty acids linked to a glycerol 3 carbon backbone o Formed by dehydration reaction take out water o Distinguished by degree of saturation length of chain Sterols o Bulky 4 ring backbone isoprene tail distinguished from one another by side groups attached to the carbons in the rings o Cholesterol Important component is plasma membranes maintains fluidity Phospholipids o Has glycerol backbone attached to charged phosphate group highly polar covalent bonds 2 fatty acid tails polar amphipathic o Upon contact with water can form Micelles tiny droplets like a circle heads face the water the tails face each other Phospholipid bilayer 2 sheets hydrophobic tails attract each other Phospholipid bilayer o Form spontaneously o Very stable energetically o Selective Permeability only allows certain molecules to pass through Small or nonpolar molecules pass easily through Higher temps make it more fluid Lipids with short unsaturated tails are more fluid Less cholesterol more permeable Bond Saturation Membrane Permeability o
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