BIOL 213 1st EditionExam # 1 Study Guide Lectures: 1 - 6Lecture 1 (September 2)What are the three central tenets of The Cell Theory? Explain what they mean.1. All organisms are composed of one or more cellsAn organism can be one cell (bacteria), or multiple cells working together to make an organism in which each cell/group of cells specializes in something to make an organism2. The cell is the structural unit of lifeCells are the smallest unit of life. Anything smaller is technically not living, like viruses3. Cells can only arise from the division of preexisting cellsMeaning cells do not spontaneously generate. This was tested in Pasteur’s experiment.What was the setup of Pasteur’s experiment? What was the experiment’s purpose? What were the results? Explain what they mean.Pasteur had two vials, one with an open neck, and one with a looped one so that nothing couldget in. Each had living material in it. He then sterilized both, thereby killing everything inside. He incubated both to see if anything would grow in the vials.The purpose of the experiment was to see how life came to be – did it come from other life, or did it spontaneously generate?The results: stuff grew in the open vial, but not in the closed one. This proved that life came from other life and that it did not spontaneously generate. If cells did not come from other cells, what would have been the outcome of Pasteur’s experiment?If cells spontaneously generated, Pasteur would have observed life growing in the vial closed tothe environment.Describe the difference between pasteurization and sterilization.Pasteurization is when some things in the product are killed. Sterilization is when everything in the product is killed. Pasteurization is useful for food, whereas sterilization is useful for health.Lecture 2 (September 4) What is the common goal of all cells? Why?DNA replication. All cells want to replicate their DNA so that they can reproduce and pass on their genetic material.Describe how cells utilize their energy most efficiently. Do only eukaryotes, only prokaryotes, or both do this?Cells utilize their energy by compartmentalizing. This means that specific processes are located in specific parts of the cell. Compartmentalization is observed in both eukaryotes and prokaryotes. Eukaryotes have membrane-bound organelles, while prokaryotes just have specific places within the cell. What are the main components of the atom, and which ones are involved in bonds?A neutral nucleus composed of neutrons and protons, and a negatively charged shell composed of electrons. Number of protons = atomic number. Number of protons and neutrons= atomic weight.Electrons are involved in bonds. Every atom wants 8 valence electrons (a full octet), so they willshare or transfer their electrons to other atoms in order to achieve this.Describe the different kinds of bonds: ionic, covalent, hydrogen, hydrophobic interactions, andvan der Waals attractions. Why are covalent bonds the most critical to biology?Ionic bond: the transfer of electrons from one atom to anotherCovalent bond: the sharing of electrons between two atomsHydrogen bonds: an attraction between a hydrogen atom and a polar atom, usually oxygen or nitrogenHydrophobic interactions: the grouping of nonpolar, hydrophobic atoms so that as little surfacearea as possible is exposed to waterVan der Waals attractions: the slight attraction between partial charges of moleculesCovalent bonds are the most critical to biology because they are the strongest in aqueous solutions. Ionic bonds break because of water’s polarity, and all of the other bonds are weaker.What are the unique properties of water that are essential to life?High boiling point: It takes a lot of energy to break the hydrogen bonds to allow the water to become gaseous. Important in sweatingHigh specific heat: Water can take in a lot of energy before increasing in temperature. Helps to regulate the earth’s temperate/climateLiquid at room temperatureLower density as solid: reason why ice floats, which is important for insulating cold bodies of waterHigh surface tension: important in capillary actionWhat is pH and what is the formula for calculating it?pH is the concentration of H+ ions in a solution. The larger the concentration of H+ ions, the lower the pH, the more acidic the solutionpH = - log[H+]Lecture 3 (September 9)What is the ionization of water? What is the formula?The switching of water molecules between 2H2O and OH- + H3O+Formula: Kw = [H+][OH-] = 1x10-14 Describe the relationship between the ionization of water, acids, bases and pH.Ionization of water: [H+][OH-] = 1x10-14  [H+]= [OH-] = 1x10-7  pH = -log[H+]= 7Acids donate H+ ions while bases take them up. More H+ ions mean more acidic because the higher concentration of H+ ions leads to a lower pH. Water is neutral because it has an equal concentration ratio of H+ ions to OH- ions.Ex: [H+]1 = 10-8  pH1 = -log[10-8] = 8 [H+]2 = 10-2  pH2 = -log[10^2] = 2 [H+]2 > [H+]1  pH2 < pH1  pH2 is more acidicWhat kind of acids and bases are most commonly found in biology? Why?Weak and reversible because strong ones would kill the cellWhat is a buffer? Why are they important to biology?A buffer is a conjugate acid and base that regulate the pH of a solution. The conjugate acid donates H+ ions when the solution is too basic and the conjugate base takes up H+ ions when the solution is too acidic. They are important to biology because they regulate the pH within the organism/cell. Organisms/cells are very sensitive to pH change.What is molarity?The concentration of a substance in moles over the volume of the solution in liters. Represented with M. M = mol/LIf you’re given the molecular weight of a substance, how would you calculate the amount of the substance you need to make a solution with a desired molarity?You multiply the molecular weight by the desired molarity. This gets rid of the moles unit. g/mol x mol/L = g/LThen you multiply by the desired volume in liters. This gets rid of the liters unit. g/L x L = gYou’re now left with grams of the substance you need to make a solution with the desired molarity.Describe the common function groups. Which macromolecules are they found in?Chemical Group Formula Characteristic Commonly foundMethyl -CH3Nonpolar hydrocarbonSome amino acids(part of side chain)Hydroxyl -OH Alcohols Carbs, lipidsCarboxyl -COOH Weak acid Amino acidsCarbonyl -Ketone