Biology 101 Professor Dhameja Micaela R Hill A soft copy of notes taken during Biology 101 in the fall semester of my freshman year at the University of South Carolina Chapter 1 Themes in the Study of Life 1 New properties emerge at each level Emergent Properties occur with the proper arrangement and interaction of parts within a system Reductionism reduce a complex system to simpler parts in order to understand how it works EP and Reductionism balance each other out Organ Organism Organelle Cell Ex a bicycle will only carry you if all parts are assembled correctly 2 Organisms interact with their environment 3 Structure and function are correlated at all levels of biological organization 4 Cells are the lowest level of organization that performs all activities required for life Prokaryotic no nucleus but still has DNA Eukaryotic nucleus containing DNA within nuclear membrane 5 Continuity of life is based on heritable information in the form of DNA 6 Feedback mechanism regulates biological systems Negative as more of a substance accumulates the process slows and less is produced Positive as more of a substance accumulates the process speeds up and more is produced Three Domains of Life 1 Domain Bacteria 2 Domain Archaea microorganisms that enjoy extremes extremophiles 3 Domain Eukarya Evolution process of change that has transformed life on Earth Cell tissue organ organ system organism population community ecosystem biosphere Chapter 2 Chemical Context of Life Element Atomic Number Valence Electrons Hydrogen H Oxygen O Nitrogen N Carbon C 1 8 7 6 1 6 5 4 Valence Bonding Capacity 1 2 3 4 Above chart compose 96 of living matter Need to know chart for exam Isotopes two atoms of the same element with a different number of neutrons Energy capacity to cause change Potential Energy location and structure Electrons Potential energy called electron shell Distribution in electron shell determines chemical behavior valence Full valence shell is chemically inert Orbital space an electron is found Types of Chemical Bonds 1 Covalent Bonds share electrons Valence bonding capacity Electronegativity attraction for electrons Nonpolar electrons are shared evenly between the two elements Polar one element is more electronegative than the other Ex H 2 O 2 Ionic Elemental Bonds transfer electrons Ion charged atom or molecule o Cation o Anion Ionic compounds or salts Van der Waals Interactions attractions between molecules that are close together as a result of positive or negative charges A molecule s shape is important to function 3 rd theme Photosynthesis 6 C O2 6 H 2 O C 6 H 2 O 6 Chapter 3 Water and Fitness of Environment Water is a polar molecule and forms hydrogen bonds between its molecules Four Properties of Water to Facilitate Life 1 Cohesive Behavior Cohesion stick to itself Adhesion stick to other things Surface Tension 2 Ability to Moderate Temperature Absorbs and releases heat with slight change in own temperature average kinetic motion energy High specific heat 1g changes 1 degree C Evaporative cooling stabilizes temperatures 3 Expansion of Water When Frozen 4 Versatile Solvent Due to polarity Surrounds solute with a hydration shell Hydrogen Ion H is transferred to a molecule The molecule with the extra proton is a hydronium ion H O and the molecule that lost the proton is a hydroxide ion O H 3 Acid increases the 5 6 Base decreases the H concentration and is 7 on a pH scale Acid precipitation has a pH H concentration and is 7 on a pH scale Buffers minimize changes of H and O H concentrations Ex Carbonic acid sodium hydroxide ammonia Chapter 4 Carbon and Molecular Diversity of Life Carbon s electron configuration tetravalence allows it to form large complex and diverse molecules Frequent Partners Hydrogen Oxygen Nitrogen Hydrocarbons carbon hydrogen release a lot of energy Isomers have the same molecular formula but different structures and properties Structural Isomers different covalent arrangements Geometric Isomers same covalent arrangements but different spatially Enantiomers mirror images of each other Functional Groups chemical groups that affect molecular function 1 Hydroxyl OH 2 Carbonyl C O 3 Carboxyl COOH 4 Amino NH2 5 Sulfhydryl SH 6 Phosphate PO4 7 Methyl CH3 ATP adenosine triphosphate primary energy transferring molecule made by mitochondria ATP has the potential to react with water and liberate energy P P P adenosine water ATP ADP Pi P P adenosine energy Chapter 5 Structure and Function of Large Molecule Polymers from monomers Polymers Carbohydrates Proteins Nucleic Acid Not Polymers Lipids Dehydration condensation a reaction that occurs when two monomers bond because of a loss of water and is sped up by enzymes Hydrolysis reverses dehydration and disassembles polymers Carbohydrates 1 Monosaccharide classified by the carbonyl group aldose or ketose C H 2 O or multiples thereof Glucose C6 H 12 O 6 is the most common monosaccharide Monosaccharides form disaccharides by dehydration and glycosidic linkages 2 Polysaccharide a Storage Starch plants in plastids Glycogen animals in liver and muscles b Structural Cellulose plant provides strength in either an alpha or beta structure becomes fiber in humans Chitin anthropods used for surgical threads Starch Cellulose Compact beta Space between structure alpha Lipids Hydrophobic 1 Fats energy storage Glycerol 3 Fatty Acids Fat Cell tryacylgycerol Ester Linkage Saturated Fats have the maximum number of hydrogens and no double bonds Unsaturated Fats have one or more double bonds and is stored in adipose tissue Trans Fats come from adding hydrogen to unsaturated fats hydrogenation 2 Phospholipids cell membranes 2 Fatty Acids Phosphate Glycerol Phospholipid Fatty acids are hydrophobic while the phosphate group is hydrophilic which forms a bilayer in water 3 Steroids Carbon skeleton in four fused rings Ex Cholesterol Proteins Enzymes are catalysts and specific type of protein Proteins consist of one or more polypeptides of amino acids 20 different kinds Synthesized in ribosomes Peptide Bonds between NH2 and COOH In a peptide chain there will be an open NH2 and an open COOH Four Structures 1 Primary unique chain of amino acids 2 Secondary hydrogen bonding occurs causing coils and folding alpha helix beta pleated sheet 3 Tertiary R groups interact 4 Quaternary multiple polypeptide chains interact Denaturation protein unravels and becomes useless Chaperonins proteins assist proper folding of other proteins Nucleic Acids Deoxyribonucleic Acid