BIOL 3442 1st EditionFinal Exam Study GuideFinal Exam Review- Homeostasis o Stability, balance, equilibrium o Regulation: receptor receives info integration center then effector sends signal o Feedback system – positive and negative o Positive feed back – amplify the chg in the variable o Negative feedback – reverse direction of chg/antagonistic control/brings body back to homeostasis o Reset system- negative fb in which a set point is adjusted (temporary, permanent or cyclic)o Levels of homeostasis  Cellular – cells control own ion concentrations, volume and internal energy  Intrinsic – tissues and organs, self serving for the particular organ  Extrinsic – external to the organ, can override cellular and intrinsic coordinated by NS and endocrine system o Animals either…  Control homeostasis strictly Avoid disturbances behaviorally  Conform but do not adjust to chgs in environmental conditions o Krogh principle – for a large number of problems, there will be some similar of choice or a few such animals on which it can be most conveniently studied o Homeostatic systems NS  Endocrine  Integumentary Muscle  Cardiovascular Respiratory  Digestive  Urinary Reproductive - Cellular o Universal life components  Water  Carbon dioxide Lipids Amino acids Nucleotideso Components of a eukaryotic cell  Nucleus – control center and nuclear DNA Ribosomes & endoplasmic reticulum – protein factory  Golgi complex – processing plant/modifies proteins  Lysosomes – cells digestive system/breaks down organic material  Peroxisomes – oxidize toxins/break down fatty acids into acetyl CoA Mitochondria – power station, krebs, DNA independent  Cellular respiration – energy production (glycolysis, krebs) Cytosol – fluid surrounding organelles/site of glycolysis  Cytoskeleton – provides structure to cells  Extracellular matrix – outside of cell, holds cells and tissues together Cell junctions – desmosomes, tight junctions, gap junctions Desmosomes – strong, meet a lot of abrasion, little communication with small space between cell junction  Tight junctions – small molecules cant get through, stomach lining  Gap junctions – proteins that form channels, open and close, brain heart tissues where cells talk w/o nerves involvement - Membrane o Phospholipid bilayer – prevents things from crossing membrane – O2 and glycose, CO2 and H2O may cross o Proteins – transmembrane protein channels allow molecules to pass membrane o Fluid mosaic model – phospholipid bilayer, embedded proteins, cholesterol, carbohydrates o Skeletal fence model – membrane proteins are constrained, tethered to membrane skeleton and limited by membrane skeleton o Diffusion – movement of solutes of area of high concentration to an area of low concentration o Conduction – charged particles moving from high to low concentration; negative to positive or positive to negative o Osmosis – diffusion by water moving water from high concentration to low concentrationo Osmatic concentration – molarity – amount of mole of substance per volume of solution; osmolality – measure of osmoles of solute particles per volume (liter) of solution o Osmolality and tonicity – both can compare the solute concentrations of 2 solutions separated by a membrane  Osmolality – doesn’t have to have membrane, take into account total concentration of all solutes, property of a solution and is independent of membrane; penetrating and non-penetrating  Tonicity – takes into account total concentration of only non-penetrating solutes,property of solute with respect to water o Hyperosmotic – comparing to something elseo Hypoosmotic –o Isosmotic – same # of solutes on both sides no net movement of water, same # of solutes on both sides, take into account is barrier is permeable to solutes o Tonicity (hypotonic) – solution the cell is in, less solutes on outside compared to inside, cell expandso Tonicity (hypertonic) – more solutes on outside compared to inside, cell shrinks o Tonicity (isotonic) – same # on inside and outside o Membrane channel Allows movement of particles through membrane (ions, water, other solutes) Passive transport – diffusion through bilayer & facilitated (concentration gradient) Active transport – moving against concentration gradient requires ATP (energy) o Ligands – intercellular chemical messengerso Paracrines – short ranged, simple diffusion, target adjacent cells o Neurotransmitters – short ranged, released by neurons in reponse to an electrical signal targets neurons muscle or gland o Hormones – long ranged via circulatory system and secreted by endocrine glands (ductless)o Neurohomones – long ranged via circulatory system and secreted by neuro-secretory neurons o Pheromones – released into the environment by glands target other animals of the samespecies o Cytokines – regulatory peptides generally involved in development or immunity, short orlong rangedo All 6 can cross or fit more than 1 of these categorieso Polarization – cell inside is more (-) than outsideo Depolarization – closer to equal w/outside of the cell more (+)o Repolarization – depolarized cell bring it back to polarized o Hyperpolarized – briefly goes lowero Ion channels  Voltage gated – triggered by charge, electrical stimuli  Ligand gated – triggered by chemicals  Mechanically gated – triggered by motion  Thermally gated – triggered by temp, heat and cold types When opened one or two reactions occur (graded or action potentials)o Graded potentials  Depolarization – occur in part of the cell membrane  Stronger the trigger the stronger the depolarization  Die out over short distances o Action potentials  Rapid and brief  Large depolarization  Nondecremental – as travels stays same level Requires a threshold potential  All or none response  Stimuli has to give mV above threshold to induce a responseo Ion channels and APs The flux of Na and K creates an AP Controlled by voltage gated ion channels on plasma membrane  K channel has 1 gate and Na channel has 2 gates  Gate 1 – activation gate – opens and Na rushes in quickly  Gate 2 – deactivation fate – closes and stops Na rushing in  Causes rapid depolarization in APs Normal resting state Na and K channels are closed  K