Biol 1108 1st EditionExam # 1 Study Guide Lectures 1-9(Note: Not including all information off the power points since they are accessible to everyone. The study guide focuses on the class discussion and learning objectives, which are the main constituents on the exam. Organized by the different sections of the course packet. )I. Levels of Learning:[Lower Levels]1. Remembering – Recognize, list, describe, identify, name, label, select, repeat, know. Can you RECALL the information?2. Understanding – remembering explanations. Interpret exemplify, summarize, paraphrase, associate, explain. Can you EXPLAIN ideas or concepts.[Higher Levels]  Active Learning3. Applying – implement, carry out, use, demonstrate, apply, transfer. Can you USE the new knowledge in another familiar situation?4. Analyzing – compare, attribute, organize, analyze, discriminate, contrast, dissect. Can you DIFFERENTIATE between constituent parts?5. Evaluating – check, critique, judge, assess, justify, evaluate. Can you JUSTIFY a decision or course of action?6. Creating – design, construct, plan, produce, integrate, synthesize, propose, invent. Can you GENERATE a new product, idea, or way of viewing things?II. Membranes and the Importance of Size Membranes: Barrier separates cells and organelles, surround cells, used for cell recognition and transport. They separate internal environment from the external environment Homeostasis: the ability to maintain a relatively stable internal environment more or less independent from external environment. (Oscillations are a sign of regulations) Structural components of membranes & their function:Phospholipids  barrierProteins  transportCholesterol regulates permeability and fluidityGlycoprotein cell recognitionCytoskeletonsintracellular transport and cell division Importance of size:Applied to cells- [supply] Surface Area (membrane): nutrients transport into cell/waste out [demand] Volume (cytoplasm): metabolism/requires nutrients/produces waste As cell size increases, the volume increases faster than the surface area. As a result, the SA/V ratio decreases. Volume is increasing by a power of 3, surface area increases by a power of 2.  Summary: As cell size increases, the volume/metabolism/demand/cytoplasm increases faster than the surface area/membrane/supply, and as a result maximum cell size is determined by demand=supply.  Use of models in biology:Question  1. Simplified problems  2. Establish rules, solution 3. Apply in biology Learning Objectives: Explain which structures represent cell volume and cell surface area: Cell volume includes all of the inside material such as the fluids and cytoskeleton with all the organelles. The cell surface is the membrane, which is made of a phospholipid bilayer.Compare and contrast the function of cell volume and cell surface area: The volume is the demand and needs all the nutrients and its main function is metabolism, while the surface’s function is to provide enough nutrients for the volume.Explain how cell volume and surface area change as cell size increases: The volume increases at a faster rate than surface area so as the cell grows the SA to V ratio decreases and becomes so small that the surface area can no longer provide for the volume.Explain what problem this generates for the supply of the cells with oxygen and nutrients: The cell is no longer able to obtain enough of each to function efficiently. Explain why it is important to look at SA/V ratio rather than at SA or V alone: Multi cellularorganisms evolved given the ratio problem by staying small but reproducing a lot. It also determines the actual capacity that the cell can reach. Explain how SA/V ratio changes as cell size increases: The ratio decreases because volume is increasing at a faster rate than the surface area. Explain why cell size is limited: If the cell gets too big, it will no longer be able to obtain the amount of nutrients needed. III. Brief History of Life on Earth, Prokaryotes & Eukaryotes BiodiversityLife characteristics: what is needed by organisms to survive DNA Metabolism Cell membranes EvolutionChange over time“Descent with modification”Processes Adaptations (non-random natural selection) Mutations (random) Genetic drift (random) Gene flow- migration What organic molecules could have existed ~3.8 billion years ago (bya)?Miller-Urey tried to mimic chemistry of early oceans/atmosphere. He added heat and sparks of electricity and analyzed what accumulated.Small organic compounds such as amino acids bases of nucleotides, lipids, sugars accumulated.Alternate source of organic molecules? Amino acids possibly from meteorites. Hydrothermal vents (hot springs) could have produced organisms as well. What properties might “protocells” have had? They had to have had a membrane-like structure around the cell.Can form spontaneously from simple precursor moleculesLipids from liposomes in water HypothesisTestable- narrow scaleThink of it as an explanation on trial. TheoryBroader scaleThere is scientific evidence to support it.Examples: gravity/ cell theory (if something is alive) / evolution The Endosymbiont Theory:Hypothesized by Lynn MargullsExplains where eukaryotes came fromDescribes Eukaryotes coming to be by the engulfing of small organisms (bacteria) by largerorganisms to use their functions and nutrients. What evidence would provide the strongest support for the theory of endosymbiosis? The fact that Mitochondria have DNA similar to bacterial DNA in sequence and structure. RNA World Hypothesis:RNA can form spontaneously from simple precursor moleculesContains limited amount of genetic informationStructural/catalytic activity & can replicate itselfGood explanation for how larger proteins and DNA were created (Last Universal Common Ancestor- LUCA) Timeline of Earth’s biodiversity: [billion years ago = bya / million years ago =mya] ~4.5 bya Earth created  ~3.8 bya Crust cools  ~3.5 bya Evidence of bacteria/prokaryotes diversify/cyanobacteria proliferate/O2 production  ~2.5-2.7 byaIron oxidized and precipitated into sediments  ~2.1 bya Eukaryotes  ~1.5-1.2 bya Multicellular Eukaryotes  ~700-600 mya Animals appear in fossil records  ~535-525 mya Cambrian explosion (O2 ~21%, similar to present)