Lecture 1 8 27 13 Cells tissues organs systems 4 primary tissues 1 Muscle 2 Nervous 3 Epithelial allow function of glands such as invagination in gland formation 4 Connective bone and cartilage a Proper dermis of skin b Cartilage c Bone d Plasma fluid but still considered a tissue Refer to cell fluid drawing on outline All must remain in homeostatic balance Plasma interstitial fluid make up ECF extracellular fluid Body systems must remain in homeostatic balance central dogma Organ systems must all be able to sense the external environment Only system that doesn t have homeostasis is the reproductive system Membrane Physiology Plasma membrane regulates volume establishes electrolyte gradients and controls selective passage of molecules Purpose of a membrane 1 Fluid mosaic model a Lipid material is mobile mosaic due to the proteins in the molecule 2 Why is a membrane needed a Need selectivity barrier b Need compartments to drive specialization of function achieve this with the membrane c 100x more volume passes through cell which means there has to be a great selectivity specificity of passage d Selectivity is governed by protein types 3 Proteins in a sea of fat Membrane lipid made up of 84 water Membrane must be composed of a non water soluble material must be non polar Polar water dissolve polar Amphipathic Hydrophilic O Hydrophobic Fatty acid hydrocarbon tails are very nonpolar Proteins are what allow the passage of molecules across the lipid bilayer Will a compound go out to in or in to out is determined by the concentration gradient higher to a lower concentration A receptor protein will bind a chemical or a ligand an external signal A passive transport protein goes across the bilayer some are always open while some have gates that are opened by the binding of a chemical Passive transport glucose cannot pass through the nonpolar regions therefore will have to bind to a specific transport protein carrier that will change its shape to allow the passage of the glucose molecule Process of facilitated diffusion will continue until concentration is equal on either side of the gradient Lecture 2 8 29 13 Scaffolds cytoskeletal elements and protein protein interactions Integral membrane proteins ion channels 1 Voltage 2 Gap junctions 3 Ligand either opens gate from inside or outside to allow permeation of specific molecules Type of protein regulates permeation or exclusion of a molecule Cholesterol molecules help improve mobility and fluidity Glycolipids proteins are ALWAYS on the external face and they help with recognition Molecules are transported across a membrane by endocytosis exocytosis and fusion of vesicles all of which require energy 1 Endocytosis allows entry of molecules across the membrane to traverse bilayer a By uptaking particulates phagocytosis cell eating b By uptaking solutes pinocytosis cell drinking c By uptaking proteins selective transporter All of these a c require energy if there is no ATP then nothing will occur 2 Exocytosis reverse process of endocytosis a Enzyme secretion b Release neurotransmitters c Secretory vesicles extrude molecules on external face 3 Fusion of vesicles Golgi apparatus a Trafficking b To the plasma membrane Molecules are transported through a membrane bilayer by 1 Simple diffusion a Doesn t require energy b Based on random walk theory random thermal motion Einstein c Will move from area of high number of molecules to low number of molecules until equilibrium is reached Fick s 1st law of Diffusion 1 Magnitude of the concentration gradient 2 Surface area of the membrane across which diffusion is taking place 3 The lipid solubility of the substance 4 Molecular weight 5 Distance through which diffusion must take place 2 Osmosis H2O will move to the side with a higher concentration of solute in order to dilute that side defined by Van Hoff s law type of diffusion 1 Flow of H2O across a semi permeable membrane 2 Passive process no energy required Hydrostatic fluid pressure pushing pressure exerted by a standing or stationary fluid on an object difference in hydrostatic pressure tends to push fluid from one side to the other Osmotic pressure pulling pressure a measure of the tendency for osmotic flow of water into that solution because of its relative concentration of non penetrating solutes and water Isotonic balanced in respect to electrolytes ions but not H2O Isoosmotic balance and equilibrium with respect to total solute concentration and total H2O concentration no net movement of H2O Hypertonic conditions Hyperosmotic environment hypoosmotic cell cell will crenate shrink Hypotonic conditions Hypoosmotic environment hyperosmotic cell cell will lyse Red blood cell 300mOsm is used as a natural osmometer 1M glucose 0 5M NaCl note NaCl in the ICF will dissociate into Na ion and Cl ion Meaning solute concentration in the cell is actually 0 5 0 5 1M 3 Protein mediated transporters a Can be either facilitated secondary active transport primary active transport or transporters exchangers b Transport is more rapid than simple diffusion c Some require energy and some do not d Saturation kinetics i The transport maximum is the fastest your carries can transport oxygen e Demonstrate stereospecifity for a molecule and will compete for structurally through your body related molecules Lecture 3 9 3 13 1 Facilitated Details of 4 classes of protein mediated transportation a Cannot move substances against a concentration gradient b Cannot move substances against an electrical gradient c Not limited to E requirement d Induction of transportation via conformational change protein carrier 2 Secondary active transport requiring ATP a An ion species typically Na will be pumped up a concentration gradient b A different ion species substance can be transported down electrical or concentration gradient w Na c Typical Na will go down concentration gradient and nutritionally important molecule will co transport up the concentration gradient ex glucose Na symport exchanger 3 Active transport a ATP E phosphorylate transfer protein to amino acid residue on a protein b Phosphorylation will alter the affinity of the transporter for molecule in order to concentrate it on one side of the membrane c Goes against the concentration gradient d Example Na K ATPase pump all cells negatively charged on the inside Lecture 4 9 5 13 Goldman ion transport according to Goldman equation is dependent on 1 Number of channels present and their densities 2 Percentage of channels that are
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