Term
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Definition
| Chemically diverse group of compounds, with the common defining feature of insolubility in water |
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Term
| Principle stored form of energy in many organisms |
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Definition
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Term
| Major structural elements of membranes |
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Definition
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Term
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Definition
| Enzyme cofactors, electron carriers, light absorbing pigments, hydrophobic anchors for proteins, hormones |
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Term
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Definition
Intracellular Signaling (cAMP,cGMP)
Signaling between nearby cells (Eicosanoids)
Signaling between tissues (Steroid Hormones) |
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Term
What is Eicosanoid?
(not from notes) |
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Definition
| Prostoglandins and related compounds are collectively known as Eicosanoids. They are produced from fatty acids and act in intracellular signaling. Act in inflammation, fever, blood pressure and clotting. |
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Term
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Definition
| An Eicosanoid that is potent but has a short half-life before being inactivated and excreted. |
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Term
| Function of Prostaglandin |
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Definition
| To exert only PARACRINE (locally active), or AUTOCRINE (acting on the same cell from which it is synthesized) |
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Term
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Definition
| In response to hormonal or other stimuli, it attacks membrane phospholipids, releasing ARACHIDONATE from the middle carbon of glycerol. |
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Term
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Definition
| Convert ARACHIDONATE to prostaglandins |
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Term
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Definition
| Lipoxygenases that catalyze the incorporation of molecular oxygen into ARACHIDONATE. |
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Term
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Definition
| Leukocytes, heart, brain, lung, and spleen. They differ in the position of the peroxide group introduced by lipoxegenases. |
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Term
| Leukotrienes have effect in... |
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Definition
| bronchoconstriction, increase vascular permeability, sustain inflammatory reactions asthmatic and allergic reactions |
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Term
Cyclooxygenase
(COX/Prostaglandin H2 Synthase) |
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Definition
| Enzyme responsible for the committed step in Prostaglanding Biosynthesis, generating Prostaglandin H2. (PGH2) |
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Term
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Definition
| Prostaglandins and Thromboxanes by various prostaglandin synthases |
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Term
| Function Prostaglandins and Thromboxanes |
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Definition
| Target specific G protien coupled receptors and play major roles in regulation of renal function, platelet aggregation, protection of the stomach lining...homeostatic tasks |
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Term
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Definition
| Catalyzed by COX: The COX activity introduces molecular oxygen to convert arachidonate to PGG2. The peroxidase activity of COX converts PGG2 into PGH2. |
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Term
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Definition
| Produced by Platelets...Formation of blood clots...reduction of blood flow to the site of clots. |
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Term
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Definition
| Synthesis of cAMP - Tissue Dependent: Functions in fever, inflammation, pain |
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Term
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Definition
| NINE on various cell types. Prostaglandins ligate a subfamily of cell surface seven-transmembrane receptors, G-protein-coupled receptors |
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Term
| Prostaglandin Receptors wide variety of actions |
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Definition
| constriction/dialation vascular smooth muscle cells, aggregation/disaggregation of platelets, sensitize spinal neurons to pain, regulate calcium movement |
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Term
| Inflammation associated with.... |
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Definition
| up-regulation of COX2 and increased formation of prostaglandins |
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Term
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Definition
| increase inflammatory disease states such as arthritis. COX2 inhibitors have been proven to work as pain relief in these cases |
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Term
| COX1 and COX2 are expressed constitutively in... |
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Definition
| the spinal cord and brain, so important in pain perception; facilitation of the transmission of pain responses within the spinal cord |
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Term
| Thrombosis/Anti Thrombosis |
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Definition
| COX2 action produces PGI2, which combats thrombosis. |
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Term
| COX2 expression in Renal Function/Edema |
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Definition
| Kidney contains constitutively COX2, selective inhibition causes sodium and potassium retention causing edema. |
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Term
| COX2: Reproductive Functions |
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Definition
| Timing of Ovulation/Parturition (PGF2)/Labor (PGI2) |
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Term
| COX2 Inhibitors: Colon Cancer |
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Definition
| Increased COX2 seen in some cancer cells, Angiogenesis essential to tumor growth requires COX2 |
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Term
| Three types of Membrane Proteins |
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Definition
1) Peripheral Proteins
2) Integral Proteins - Hydropathy Index
3) Covalently attached proteins |
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Term
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Definition
| Sharp tip of microscope probe attached to flexible cantilever is drawn across membrane. Forces move the proble up and down as it encounters hills and valleys, a laser beam detects motions of a little as 1A. |
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Term
| Membrane Rafts; Microdomains |
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Definition
| Raft regions have greater thickness, can be visualized by atomic force microscopy. Rafts protude from a lipid bilayer ocean, sharp peaks are GPI linked proteins |
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Term
Membrane Rafts;Microdomains
Glycosphingolipids |
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Definition
| contain long chain saturated fatty acids, form transient clusters with each other and cholesterol |
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Term
| Microdomains (rafts) are... |
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Definition
| slightly thicker and more ordered (less fluid) |
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Term
| Membrane Rafts;Microdomains are enriched in... |
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Definition
| proteins that are anchored to the membrane by two covalently attached long chain saturated fatty acids and GPI anchored proteins |
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Term
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Definition
| as much as 50% of total membrane area |
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Term
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Definition
| for a process that involves interaction of two membrane proteins, their presence in a single raft increases the liklihood of a collison |
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Term
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Definition
| Lipid Aggregate: round unit one layer: heads outside |
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Term
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Definition
| Lipid Aggregate: Flat with two layers, heads facing out |
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Term
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Definition
| Lipid Aggregate: Round two layer with heads facing out and in |
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Term
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Definition
| individual lipid and protein units in a membrane form a fluid mosaic with a pattern that is free to change constantly b/c interaction among its components are noncovalent, leaving individual lipid and protein molecules free to move laterally in the plane of the membrane |
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Term
Liquid v. Gel:
Long chain saturated fatty acids |
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Definition
| Pack Well; Higher Melting Point; Favor Gel Phase |
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Term
Liquid v. Gel:
Unsaturated Fatty Acids |
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Definition
| Pack less well; lower melting point; favor liquid disordered state |
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Term
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Definition
| Rigid Planar Structure; interacting fatty acids are fully extended; favor gel phase |
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Term
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Definition
| Diffusion of a lipid molecule from one leaflet of the bilayer to the other occurs very slowly. Requires a polar head to leave its aqeous environment and move into hydrophobic interior, takes a large positive free energy charge |
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Term
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Definition
| Rapid diffusion within a confined region with occasional hops into an adjoining region |
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Term
| Membrane Skeleton exists of... |
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Definition
| long filamentous SPECTRIN protein, cross-linked at junctional complexes with ACTIN |
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Term
| Lateral Diffusion of Proteins |
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Definition
1) Many membrane proteins show the same diffusion behavior as the membrane lipids
2) Some membrane proteins associate to form large aggregates on the surface of a cell in which individual protein molecules do not move relative to one another
3) other proteins are anchored to internal structures that prevent their free diffusion |
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Term
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Definition
| association between cells and the proteoglycan of the extracellular matrix |
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Term
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Definition
| has four extracellular Ca2+ binding domains, the most distal of which contains the site that binds to cadherin on another cell surface |
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Term
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Definition
(nerual cell adhesion molecule)
immunoglobin-like proteins that mediate Ca2+ independent interactions with surface proteinsof nearby cells |
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Term
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Definition
| bind tightly (Ca2+ dependent) to carbohydrate moieties in neighboring cells |
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Term
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Definition
| the fluidity of the cell membrane allows it to take part in processes like membrane fusion without breaking apart |
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