BIOL 1361 1st EditionExam # 2 Study Guide Lectures: 9 - 18Lecture 9 (September 29)A compound containing carbon is called an organic compound. Carbon chains form the skeletons of most organic molecules and can be unbranched or branched, can contain double bonds, or can have rings. The 7 functional groups are:- Hydroxyl group –OH o Polaro Forms H Bondso May act as a weak acid- Carbonyl group C=Oo Polaro Found in many sugars- Carboxyl group –COOH o Acts as an acid- Amino group –NH2o Acts as a baseo Attracts H+- Sulfhydryl group –SHo Can form disulfide bridges- Phosphate group –OPO32-o Strong potential to react with water and release energyo Contributes negative charge- o Ex. ATP- Methyl group – CH3o Reduces reactivity of compoundsFats can be either saturated or unsaturated. A triglyceride is a type of fat that is composed of 3 fatty acids and a glycerol. A phospholipid is a glycerol, 2 fatty acids, a phosphate group, and a choline joined by an ester linkage that was formed through dehydration. Phospholipids form a bilayer in an aqueous solution with their hydrophobic tails associating with each other and theirhydrophilic heads interacting with the aqueous solution. Phospholipids also form organelles andcell membranes. A steroid has a carbon skeleton of 4 rings.The difference between saturated fatty acids and unsaturated fatty acids:o Saturated Fatty Acid Do not have kinks Hydrocarbon chain has single bonds- Carbons are saturated with H The chain is packed tightlyo Unsaturated Fatty Acid Has kinks Hydrocarbon chain has double bonds- Carbons are not fully saturated by H The chain is not packed tightlyThe functions of fats, phospholipids, and steroids can be described as:o Fat Can change fluidity of the membrane Can store energy  Can help to insulate the body and cushion to protect organso Phospholipid Forms organelles and cell membranes Form a bilayer in aqueous solutionso Steroids Ex. cholesterol Cholesterol in a membrane changes viscosity (a fluids resistance to flow)- In low temp: cholesterol prevents too much phospholipid packing- In high temp: cholesterol prevents too much phospholipid movementLecture 10 (October 1)A monomer is a molecule that can bond to other identical molecules and form a polymer. A polymer is a molecule that is composed of repeating monomers joined by covalent bonds. Monomers are linked by dehydration reactions, which is the removal of an O and 2 H. An Ex. Amino acids are monomers, when linked together by a peptide bond, they are a polypeptide which is the polymer.The primary structure of an amino acid is simply a linear chain of amino acids. It has an NH3amino end and another COOH carboxyl end.The secondary structure has coils and folds. There are H bonds between O and H of the amino acid backbone and there are two types: alpha helices and beta pleated sheets. The tertiary structure is the final 3D structure of the protein due to interactions of the side chains with each other. There are hydrophobic interactions and disulfide bridges here. The quaternary structure is a protein with 2 or more polypeptides. Examples include insulin, collagen, and hemoglobin. A slight change in primary structure can affect a proteins shape and ability to function with the example of sickle cell.A nucleotide is composed of a sugar, a phosphate group, and a nitrogenous base. RNA contains the sugar ribose and has the nitrogen bases of GCAU. DNA contains the sugar deoxyribose and has the nitrogen bases of GCAT. Lecture 11 (October 6)o Prokaryotes Single-celled organisms Cell membrane + cell wall 1 circular chromosome No membrane bound nucleus or other organelles- But they have infoldings of plasma membrane that provide specialized function DNA is in the nucleoido Eukaryotes Single-celled or multicellular Cell membrane (+cell wall, plants and fungi) Linear chromosomes Membrane-bound organelles- Cellular components where specific functions are performed DNA is in the nucleusHere is a brief description of some eukaryotic organelles we discussed in class:o Nucleus Contains genes Is double membrane boundo Smooth ER Synthesizes lipids Metabolizes carbohydrates Detoxifies drugs and poisons Stores calcium ionso Rough ER The site of protein synthesis- The ribosomes synthesize proteins The membrane factory for the cell- It grows by adding membrane proteins and phospholipids to its own membraneo Lysosome Are vesicles (sacs of membrane) filled with enzymes that digest biomolecules They dispose of cellular debris and worn out organelleso Golgi Apparatus Proteins made in the rough ER are wrapped in vesicles that fuse with the Golgi Apparatus and deliver the proteins. Within the Golgi Apparatus, proteins are modified or stored, then re-wrapped in vesicles to travel to the final destination o Mitochondria The site for cellular respiration, the metabolic process that uses oxygen togenerate ATP by extracting energy from sugars, fats, and other fuelso Chloroplasts The site for photosynthesis, Chloroplasts convert solar energy to chemical energy by absorbing sunlight and using it to drive the synthesis of organic compounds such as sugars from CO2 and waterLecture 12 (October 8) The Laws of Thermodynamics:- The first law of thermodynamics: energy can be transferred or transformed but cannot be created or destroyed. There are two types: kinetic and potential- The second law of thermodynamics: every energy transfer or transformation increases entropy of the universe.Free Energy, G – is energy available to do work. ΔG is the change in energy during a chemical reaction. ΔG = Gfinal – Ginitial. Exergonic Reactions vs. Endergonic Reactionsa. Exergonic Reactioni. ΔG is negativeii. Energy of the products is lower than the energy of reactantsiii. Is spontaneous (not fast, but can occur w/o adding energy)b. Endergonic Reactioni. ΔG is positiveii. Energy of products is greater than energy of reactantsiii. Not spontaneous – energy MUST be added to make the reaction happenLecture 13 (October 13)An enzyme is a macromolecule that acts as a catalyst, a chemical agent that speeds up a reaction without being consumed by the reaction. It binds to a substrate, decreases the activation energy by pulling and stretching chemical bonds of the substrate, and is recycled when the reaction is completed, not consumed. Enzyme Activity is the rate at which an