Lecture Notes 1 PDF

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Lecture Notes 1 Chapter 1 Introduction to Physiology About This Chapter • Physiology is an integrative science • Function and mechanism • Themes in physiology • Homeostasis • Control systems and homeostasis • The science of physiology Physiology Is an Integrative Science • Integration of function across many levels of organization – Complex systems have emergent properties Moving Beyond the Genome • Genomics – Study of all of the genomes of an organism – Human Genome Project • Proteomics – Study of all of the proteins of an organism • The Physiome Project – Molecular, cellular, and physiological information • Translational research Levels of Organization • Physiology defined – Study of the normal functioning of a living organism and its component parts • Includes all its chemical and physical processes • Organization of life – The cell is the smallest unit of structure capable of carrying out all life processes – Atoms, molecules, cells, tissues, organs, organ systems, and organisms

Organ Systems in Review • Integumentary • Musculoskeletal • Respiratory • Digestive • Urinary • Reproductive • Circulatory • Nervous

• •

Endocrine Immune

Mapping • Organizational tool for relationships and processes • Schematic diagram of structure and function – Atoms, molecules, cells, tissues, and organs • Flow charts – Diagram processes in sequence Function Versus Process • Function explains the “why” – Teleological approach • Process or mechanism describes the “how” – Mechanistic approach • Red blood cell example – “Because cells need oxygen and red blood cells bring it to them.” – “Oxygen binds to hemoglobin molecules contained in the red blood cells.” Themes in Physiology • Structure and function are closely related – Molecular interactions – Compartmentation • Living organisms need energy • Information flow coordinates body function • Homeostasis maintains internal stability

Homeostasis • Regulation of the body’s internal environment • Keeping internal environment stable • Interaction between – Outside world – Extracellular fluid – Intracellular fluid Homeostasis • External or internal change • Loss of homeostasis – Sensed by organism • Physiological attempt to correct • Dynamic steady state – Not the same as equilibrium

Homeostasis • Successful compensation – Homeostasis reestablished • Failure to compensate – Disease • Study of failure to compensate is pathophysiology Control Systems and Homeostasis • Regulated variables are kept within normal range by control mechanisms – Keeps near set point, or optimum value • Control systems – local and reflex – Input signal – Integrating center – Output signal Control Systems and Homeostasis • Local control • Reflex control – Long-distance pathway – Uses nervous and/or endocrine systems – Response loop – Stimulus, sensor, input signal, integrating center, output signal, target, response – Feedback loop – Negative feedback stabilizes variable – Positive feedback reinforces stimulus – Feedforward control anticipates change

Biological Rhythms • Regulated variables create repeating patterns – Daily circadian rhythms • Acclimatization occurs naturally • Acclimation in a laboratory setting Experimental Design • Hypothesis • Independent and dependent variables • Experimental controls • Data collection and replications • Difference between models and theories Interpretation of Human Experiments • Difficult to interpret results – Genetic and environmental variability – Crossover studies – Placebo effect and nocebo effect

– Blind, double-blind studies, and double-blind crossover studies – Ethics of humans as test subjects Experimental Design Formats • Longitudinal studies versus cross-sectional studies • Prospective versus retrospective studies • Meta-analysis About This Chapter • Physiology is an integrative science • Function and mechanism • Themes in physiology • Homeostasis • Control systems and homeostasis • The science of physiology

Chapter 2 Molecular Interactions About This Chapter • Molecules and bonds • Noncovalent interactions • Protein interactions Biomolecules • Organic molecules contain carbon – Biomolecules are associated with living organisms – Carbohydrates, lipids, proteins, nucleotides – Conjugated proteins (e.g., lipoproteins; blood transport molecules) – Glycosylated molecules (e.g., glycoproteins, glycolipids) in cell membranes – Polymers made of repeating unit

Molecules and Bonds • Bonds link atoms • Bonds store and transfer energy • Molecules versus weaker interactions Functional Groups • Combinations of elements that occur frequently in biological molecules • Move along molecules as a single unit Four Important Roles of Electrons • Covalent bonds • Ions • High-energy electrons

•

Free radicals

Types of Chemical Bonds – Covalent Bonds • Covalent bonds – Share a pair of electrons – Single, double, and triple bonds – Polar versus nonpolar molecules Types of Chemical Bonds – Ionic Bonds • Ionic bonds – Atoms gain or lose electrons – Opposite charges attract Ions • Ions are charged atoms – Cations – Lost electrons – Positively charged (+) – Anions – Gained electrons – Negatively charged (−) Types of Chemical Bonds – Hydrogen and Van der Waals • Hydrogen bonds – Weak and partial – Water surface tension • Van der Waals forces – Weak and nonspecific Aqueous Solutions • Aqueous – Water-based • Solution – Solute dissolves in solvent • Solubility – Ease of dissolving – Hydrophilic – Hydrophobic Molecular Shape and Function • Molecular bonds determine shape – Shape is closely related to function • Proteins have the most complex and varied shapes – Secondary structures: alpha-helix and beta-pleated sheets – Fibrous proteins – Tertiary structure

– Globular proteins – Disulfide bonds (S-S) Hydrogen Ion Concentration (pH) • Free H+ can change a molecule’s shape • pH – Measure of the concentration of free H+ • Acid – Contributes to H+ solution • Buffer moderates changes in pH Soluble Protein • Enzymes • Membrane transporters • Signal molecules • Receptors • Binding proteins • Immunoglobulins • Regulatory proteins Protein Interactions • Binding – Noncovalent bonds with other molecules – Occurs at binding site – Go to a state of equilibrium • Ligands – Substrates • Proteins are specific about bonding • Molecular complementarity – Induced-fit model – Affinity Dissociation Constant Indicates Affinity • Dissociation constant (Kd) • Competitors • Agonists Multiple Factors Affect Protein Binding • Isoforms • Activation – Proteolytic activation (lysis) – Cofactors • Modulation/modulators – Chemical modulators – Competitive versus irreversible antagonists – Allosteric versus covalent modulators

– Physical factors Body Regulates the Amount of Protein in Cells • Up-regulation • Down-regulation Reaction Rate Can Reach a Maximum • Concentration of ligand • Maximum reaction rate – Saturation About This Chapter • Molecules and bonds • Noncovalent interactions • Protein interactions...