Biology Notes Outline Biomes:- Deserts o dry, occasional rain, hot during day but cooler at nighto deserts are caused by rotating air currents – hot air rises along the earth and cool air falls, so some areas are warmer while some are coolero precipitation is rare but sudden, so animals adapt to efficiently use/conserve available watero intense heat causes high rate of evaporation- Tundraso High latitude/altitudeo Most soil is rich, but permafrost (lower levels of ground frozen) existso Permafrost causes water shortages, most available water is during the summer when permafrost melts and standing pools become availableo Cold is extreme, low evaporationThermoregulation:- Biochemical reactions require energyo Too cold – metabolism can’t occur because there’s not enough energyo Too hot – enzymes and their substrates denature, meaning the organism that the enzyme is on changes shape. Ex. Egg boilingo Basically, enzymes only function best at certain temperatures and have adapted todifferent environments- Radiation – heat transfer not in direct contact, Ex. The sun- Convection – heat transfer through mass amount of fluid (gas, liquid, whatever) Ex. A toaster oven- Conduction – direct heat transfer, Ex. An iguana on a rock- Evaporation – loss of waterGRADIENT: cycle/transfer of energy, heat, salts, water, whatever, to reach an equilibrium state- Poikilotherms: CAN’T thermoregulate on their own, their internal temperature reflects external temperature- Homeotherms: CAN thermoregulate on their own, their internal temperature maintains no matter what the external conditions through adapting (sweating, shivering, etc.)- Endotherms: can live anywhere, don’t need to warm up, internal temp. is constant and uses enzymes (sometimes) to maintain it, Ex. humans- Ectotherms: lower energetic needs, don’t have a constant internal tempHow Thermoregulation Works:THERMAL NEAUTRAL ZONE: temperature range where an organism can maintain its metabolismSee graph.When the external body temperature rises/falls past a certain point, the metabolism makes up the difference by working extra hard (sweating/shivering). Additionally, surface area can influence temperature. By reducing surface area, an animal reduces area exposed to cold and the opposite is true for hot temperatures.- Avoidance:o Move in/out of shadeo Burrowo Huddleo Position near/away from heat sourceo Migrateo Hibernateo Become nocturnalOther Avoidance Techniques- Countercurrent – close organisms exchange heat to reach a gradient- Vasoconstriction – reduced heat loss by conduction/convection (warm up)- Vasodilation – increased heat loss by conduction/convection (cool down)- Insulation:o Fat reserveso Fur/feather/hairo Barrier of still air to prevent convection- Evaporation – sweating, panting- Generate heat – shivering (food converts from potential energy to kinetic energy in the muscle and heat is released)- Non-shivering thermogenesis – same bodily process as shivering minus the actual shivering, done automaticallyOsmoregulation: transfer of water/salts through tubules, how our bodies maintain homeostasis- Metabolic reactions include water as a byproductC6H12O6 + O2 -- ATP + CO2 + H20This is the formula for ‘life’- Diffusion – random motion that spreads particles from regions of high concentration (salt, glucose, whatever) to low concentration- Osmosis – functions the same as diffusion, but when water is traveling through the semipermeable membrane along a concentration gradient- Tonicity – measure of the osmotic pressure gradient of 2 solutions separated by a semipermeable membrane (water and salt)o Hypotonic – water is attracted to cells/areas of high sugars or salts, excess watero Hypertonic – water leaves the cells and they dehydrate, high sugar/salt concentrationso Isotonic – balanced water/salt ratioMembrane Structure- Phospholipid bilayer – lots of water inside, no water outside, inbetween cytoplasm and extracellular fluid- Passive Transport – no energy reguired (salts/waters leaving the kidney)- Active Transport – energy required (salts/waters entering kidney)Cellular RespirationOxygen and Glucose consumed………………………….carbon dioxide and ATP releasedO2 + C6H12O6  CO2 + ATP- Breaks down molecules with high potential energy like a “controlled burn”- Performed in separate compartments of organelles- Cell Structure:Animalso Outside – extracellular fluido Inside – cytoplasmo Phospholipid bilayer inbetween themo Center – nucleuso Endoplasmic reticulum – rough with ribosomes/smootho Golgi apparatus – lipid synthesiso Mitochondria – CELLULAR RESPIRATION OCCURS HEREPlants- Cell wall- Chloroplasts – photosynthesis- Similar structures- Vacuole for storageProkaryotes- lack most cell organells- simple cell membrane and nucleusMITOCHONDRIA:- has own double membrane- in all eukaryotic cells (plants/animals)- space between membrane – inner membrane- matrixCellular Respiration- glucose gained from food intake- ATP is the energy carrying molecule- Phosphate bonds have high energy content – they are broken during glycolysis and such and energy is released- ATP TO ADP: release of energy (exergonic)- ADP TO ATP: requires energy (endergonic)- Enzymes are required for these chemical reactionso Co-enzymes are non-protein compounds that help enzymes catalyze a reaction- NAD+ is a high energy form of NADHGlycolysis: Glucose splits in two molecules of pyruvate, changes molecules for energyTwo Main Stages –1. Glucose Activation- Requires energy (2 ATP)- Happens in cytoplasm2. Energy Extraction- ATP (4 molecules) harvested VIA SUBSTRATE LEVEL PHOSPHORYLATION WHAT- 2 NADH molecules produced in pyruvate oxidationIn summary: six carbon atoms pay 2 ATP to go through process which produces four ATP molecules, so ultimately glycolysis produces 2 ATP molecules as well as 2 NADH molecules and pyruvate. The process depletes NAD+ so fermentation occurs to replenish it, but fermentation does NOT create ATP.- anaerobic process – does no require oxygen- pyruvate ferments w/out oxygen which replenishes NAD+ supplies so glycolysis can continueAcetyl CoA - happens in aerobic organisms- short process- Acetyl group enters, loses CO2 and NADH, is joined by CoA and goes to Krebs CycleKrebs Cycle- Very complex- Takes place in the mitochondriaCycle:Pyruvate  Acetyl CoA combines with oxaloacetate  citrate- Yields 2 ATP, 6 NADH, 2 FADH2 (specific to Krebs cycle), 4CO2 molecules-