BIO 251 1nd Edition Lecture 2Outline of Last Lecture I. Organization of bodya. Cellsi. Basic cell functionsii. Specialized functionsb. Primary tissuesi. Nervous tissueii. Epithelial tissueiii. Connective tissueOutline of Current Lecture I. PerturbationsII. DNAIII. Tay Sachs DiseaseIV. Cell energeticsV. Oxidative DamageVI. OrgansVII. FunctionsVIII. Organization of body-functionsIX. Homeostasis These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.X. CytoplasmXI. OrganellesXII. Cytosol XIII. CytoskeletonXIV. MicrofilamentsXV. Oxidation of glucoseCurrent LectureI. Perturbationsa. To understand how body works we will frequently examine how body responds toperturbations caused by i. Diseaseii. Exercise1. In cells oxygen drops and CO2 goes upa. Increase breathing (rate and volume)b. Increase heart beat speed and strength2. Energy used up, muscle fuel depleteda. Liver releases glucose, adipose tissue releases fatty acids3. pH in ECF dropsa. Release of chem buffers by blood and kidneys b. Increase in breathing 4. Body heats upa. Blood flow to skin increasedb. Glands increase sweat productionII. Objectives of topic 2a. Find way around celli. Focus on structures that will be important laterb. Identify basic energy currency of cell and primary ways it is producedIII. DNAa. DNA transcribed into RNA in the nucleusb. RNA translated into protein on the ribosomes in the cytoplasmc. NOTE: some DNA is regulatory and does not code for proteinIV. Tay Sachs Diseasea. Fatal genetic disorder--single gene malfunction b. Caused by the accumulation of a fatty ganglioside in the nerve cells in the brain because of a single enzyme deficiency inside lysosomec. Infants develop normally for a few monthsd. As nerve cells fill with fat, mental and physical abilities deteriorate because electric currents not propagated properlye. Child become blind, deaf, and unable to swallowf. Muscles atrophy and paralysis ensuesg. Death by age 5---no cureV. Cell energeticsa. Energetic currency of cell: ATOPb. ATP-->ADP + Pi + energy c. It is the splitting of the phosphate from ATP that generates energy used for:i. Synthesis of new componentsii. Membrane transportiii. Mechanical work (e.g. muscle contraction)VI. Oxidative damagea. Free oxygen radicals (e.g. O2-) produced during oxidative phosphorylation b. Highly dangerous and damage cell membranes, proteins and DNA c. Antioxidants eliminate most of them d. But oxidative damage the mostly likely proximal cause of aging and many diseasesD. Organs1. Composed of two or more primary tissues organized to perform a specific function2. Example: Stomach is composed ofa) epithelial tissue (restricts transfer of digestive enzymes to blood; exocrine glandssecrete digestive enzymes; endocrine glands that secrete hormones that regulatemuscle contraction & exocrine secretion)b) smooth muscles tissue (mixes & propels food)c) nervous tissue (controls contraction & secretion)d) connective tissue (holds all together)E. Body Systems1. Collection of organs that perform related functions and interact to accomplish acommon activity essential to survival of body.2. Example: Digestive system composed of: mouth, pharynx, esophagus, stomach, small & large intestines, salivary glands, pancreas, liver, and gallbladder.III. Theme 2: Organization of the Body: Compartments and FunctionA. Let’s see how the overall body plan is divided into different fluid compartments (Fig 1.4); interactions between these compartments drives much of the function we will study (e.g., how nerves generate electrical signals; overall cardiac function)B. Fluid Compartments within Body (Fig 1.5)1. Intracellular Fluid (ICF)a) Fluid within cells2. Extracellular Fluid (ECF)a) Fluid outside cellsb) Further compartmentalized into(1) Plasma (liquid portion of blood)(2) Interstitial fluid (fluid that surrounds cells)(3) Boundry between the 2 is capillary walls(4) Water and small molecules can move freely across capillaries3. Boundry between ECF and ICF are cell membranesIV. Theme 3: HomeostasisA. Definition & Concepts:1. Keeping the internal environment constant (Fig 1.4)a) This must be done to maintain cell function2. Environment of Cell is the ECF (blood plasma, interstitial fluid).B. Factors that must be homeostatically maintained: ECF volume, composition and temperature.C. For every body system that we study, we will examine how that system is regulated to maintain homeostasis (e.g., the urinary system producing urine with the needed balance of water and salts)D. Regulation of Homeostasis1. Negative feedback control (Figs 1.6 and 1.7) is most common2. Positive feedback control does occur sometimes (Fig 1.8)I. General StructureA. 75 trillion cells in bodyB. Major parts (Fig 2.15)1. cell membrane (sometimes called plasma membrane)2. nucleus3. cytoplasmC. Cell (or plasma) membrane (Fig 2.16)1. Thin structure2. Encloses each cell3. Mechanical barrier that is selectively permeable4. Intracellular fluid (ICF) fluid inside cell5. Extracellular fluid (ECF) fluid outside cellsD. Cytoplasm (2.15)1. That part of cell that is not nucleus.2. Contains membrane enclosed organelles dispersed in a gel like mass called cytosol3. Organelles are separate compartments specialized for particular functions4. Cytosol is semiliquid mass laced with elaborate protein network called Cytoskeleton.E. Nucleus (Fig 2.18)1. distinct sphere in center with its own membrane2. contains DNA which is packaged into chromosomesa) DNA is transcribed into RNA in the nucleusb) RNA is translated into proteins on the ribosomes in the cytoplasmII. Organelles (see Table 2.2 for summary)A. Endoplasmic reticulum1. Structure (Fig 2.19)a) One continuous organelle; membrane continuous with nuclear membraneb) fluid filled membrane structurec) two types: rough (RER; closest to nucleus) & smooth (SER; continuous w/ RER)2. Function of RERa) is rough because of attached ribosomesb) ribosomes synthesize proteinsc) RER involved in synthesis and release of proteinsd) Lots of RER found in cells specialized for protein synthesis3. Function of SERa) Discharge site for molecule transport from ER to Golgi complex.b) Piece of SER pinches off with molecule inside; called a transport vesiclec) Some cells: SER specializes in lipid synthesis & transportd) Liver cells: SER detoxifies harmful chemicals & excretes themB. Golgi complex (Figs 2.20)1. Structurea) Flat, slightly curved membrane