Biol 2420 - Physiology Exam I Practice Test Questions And Answers100% Pass.

Define physiology and explain how it is related to other science disciplines. - correct answer the study of functioning of a normal living organism and its component parts, including chemical and physical processes List the levels of structural organization that make up the human body and explain how the levels increase in complexity - correct answer atom - molecules - cells - tissues - organs - organ systems - organisms - populations of species - ecosystem of diff species - biosphere Explain how the organ systems cooperate to maintain the well-being of the human body. Be able to describe examples of interdependence between organ systems. - correct answer 10 systems (circulatory, digestive, endocrine, immune, integumentary, musculoskeletal, nervous, reproductive, respiratory, urinary) E.g. body fluid volume influences blood pressure which alters kidney function because kidneys regulate fluid volume Distinguish between teleological and mechanistic approaches to physiology questions. Be able to give an example of each. - correct answer function is the why - not a theme of physiology (teleological approach); cells need oxygen so RBC's bring it to them mechanisms is the how - the processes; oxygen binds to hemoglobin mol's contained in the RBC's Identify the major themes/concepts in Physiology and describe an example of each: - correct answer • Structure/Function Relationships -structure and function -functional groups of proteins: enzymes, signal molecules, receptor proteins, and specialized proteins (biological pupms, filters, motors, transporters) -compartmentation (compartments within the cell; separation allows cells to regulate metabolic reactions by isolating ezymes within organelles • Biological Energy Use • Communication • Movement • Homeostasis • Evolution underlies all Biology Define homeostasis and explain its importance and be able to describe examples. - correct answer maintenance of relatively stable condition of body's internal enviro eg. temperature, pH, ion concentrations, oxygen, and water Recognize the consequence of failure to homeostasis. - correct answer failure to compensate; leads to illness or death; internal failure (abnormal growth of cells, autoimmune diseases, premature death of failure of cell processes); external failure (toxic chemicals, physical trauma, foreign invaders-bacteria or viruses response loop - correct answer stimulus - sensor - input signal (afferent) - integrating center - output signal (efferent) - target/effector - response Explain how homeostasis maintains a stable internal environment and why homeostasis does not always equal equilibrium. - correct answer dynamic steady statel keeps system at or near a setpoint H2O is in osmotic equilibrium (free movement) chemical and electrical disequilibrium necessary for function; selective permeability gradients in ICF and ECF Recognize how the law of mass balance helps maintain homeostasis and list the sources of input and output in the body. - correct answer if the amount of a substance in the body is to remain constant, any input must be offset by an equal loss. E.g. water output occurs thru excretion or metabolism Explain how control mechanisms maintain homeostasis: Contrast local control vs long distance (also called reflex) control - correct answer local control: simplest homeostatic control; autocrines & paracrines, restricted to a tissue or cell involved; eg. scratch swells and turns red; pressing on finger cuts blood supply long distance (reflex) control: nervous, endocrine, both; systemic; eg maintaining blood pressure Contrast negative feedback vs positive feedback (which is stabilizing?) and describe examples. - correct answer negative feedback maintains homeostasis; response opposes or removes the original stimulus which stops the response loop; stabilizes the regulated variable; can restore normal state but cannot prevent initial disturbance positive feedback - response reinforces the stimulus; eg oxytocin release during labor; depolarization spike; sends system temporarily out of control, requires intervention/event outside the loop to stop the response Explain setpoints and variations of setpoints: Recognize examples of biological rhythms. - correct answer biological rhythms result from predictable changes in setpoint: circadian rhythm; GnRH, LH release; seasonal breeding in animals change predictably List the steps of the scientific method and the necessary parameters. - correct answer observe - hypothesis - experiment - collect data - conclusion must be testable Contrast dependent and independent variable in an experiment, and be able to interpret data portrayed on graphs. - correct answer independent variable = altered variable (manipulated) dependent variable is observed; dependent variable is dependent on independent variable control - duplicate of experimental group except independent variable is maintained at the initial value crossover study - each individual acts as both experimental subject and control Explain the value and limitations of human studies. - correct answer variability - dissimilar test subjects psychological factors-placebo vs nocebo effects ethical considerations-withholding meds from very sick people Use blind, double blind, double blind crossover studies Prospective studies: looking forward Retrospective studies: looking backward *Explain how the study of physiology depends on the study of chemistry. - correct answer explains the 'how' of the body functions; mechanistics *Define radioisotope and describe an application of radioisotopes in research or medicine. - correct answer have an unstable nuclei; emit energy -> radiation; researchers use as tracers; eg. iodine in thyroid I 127 normal, I 131 abnormal Explain the roles of electrons in bond formation and list the four major types of bonds and relative strengths. - correct answer Covalent bonds - strong bonds; form when atoms share one or more pairs of electrons; require energy to break Ionic bonds - strong bonds formed when oppositely charged ions are attracted to each other; electrons pulled from one atom to another hydrogen bonds - weak bonds that form hen hydrogen atoms in polar mol's are attracted to O, N, F; causes water surface tension; important for protein shape van der waals - weak bonds; move closer together until too close and then repel; help protein hold their shape Discuss the importance of water in the body and how its molecular structure allows it to carry out its important roles - correct answer universal solvent for biological solutions is water hydrophilic mole's dissolve easily in h2o Define and contrast: • Solution vs solute vs solvent • Solubility: hydrophobic vs hydrophilic - correct answer solute + solvent (h2o) = soution solubility - the ability of a solute to dissolve in a solvent; hydrophilic mol's have high solubility in h2o; hydrophobic's don't *Explain the concept of pH (what it measures) and how a pH scale is used. Give an example of a pH dependent process in the body. - correct answer measurement of hydrogen ion concentration One digit change = 10x more/less conentrated mole molarity equivalents - correct answer mole: 6.02 x 10^23 molarity: one mole/L equivalents: molarity multiplied by charge *Define buffer; list the most important buffer systems and their importance in the body. - correct answer sol'n that moderates pH changes HCO3^- is a blood buffer ****most important buffer systems in the body*** *Explain how the shape of each protein is determined by the order and properties of its amino acids. - correct answer proteins- CHON(S); made up of amino acids; structure and function; each has an amino (nitrogen containing) group and an acid (carboxyl) group and a unique side group attached to the central carbon that gives each protein its characteristic shape that enables it to carry out its function *Compare and contrast the four classes of biomolecules in terms of their building blocks, different forms, and functions in the body. - correct answer organic mol's assctd with living organisms; have a carbon backbone (chain or ring); always contain H and O; CHNOPS (phosphorus, sulfur) 1.Carbohydrates - most abundant biomol; monosaccharides, disaccharides, polysaccharides 2. lipids -nonpolar; saturated and nonsaturated; fats and oils; 5 classes: eicosanoids (signaling mol's), phospholipids, steroids, triglycerides, ketones 3 proteins- CHON(S); made up of amino acids; structure and function; each has an amino (nitrogen containing) group and an acid (carboxyl) group and a unique side group attached to the central carbon that gives each protein its characteristic shape that enables it to carry out its function 4. nucleotides (DNA, RNA-structural components of genetic matter, ATP -carry energy, cAMP-regulate metabolism) combination biomolecules - correct answer lipoproteins - blood transport molecule glycoprotein- membrane structure glycolipid - membrane receptors *Describe how proteins are able to carry out their specific roles based on specific structure. - correct answer primary structure- 20 protein-forming aa's assemble into polymers called 20 aa's can create an almost infinite number of combinations; sequence of AA's secondary - covalent bond angles between aa's determine secondary structure; alpha helix and beta pleated sheet tertiary structure - is the 3D shape; fibrous proteins and globular proteins quaternary structure-multiple subunits combine with noncovalent bonds. folding patters of a protein are determine by interaction of R-group side chains and sequence of AA polypeptide chains; hemoglobin mol's are made from four globular protein subunits, one AA change =sickle cell; multiple subunits *Explain why and how proteins interact (bind to each other). Hint: Consider structure - correct answer they bind to other molecules through noncovalent interactions: specificity, affinity, competition, saturation binding sites dependent upon the structure peptide to protein - correct answer peptide (2+ AA's) -> oligopeptide (<10 AA's) -> polypeptide (10+ AA's) -> protein a carboxyl group of one molecule reacts with the amino group of another molecule creating a peptide bond and releasing a water molecule ligand - correct answer any molecule that binds to another molecule ligands that bind to enzymes and membrane transporters are also called substrates soluble proteins - correct answer proteins include enzymes, membrane proteins, signal mol's, receptors, binding proteins, regulatory proteins, immunoglobulins specificity - correct answer ability of a ligand to bind to certain ligands and not to unrelated ligandsffin affinity - correct answer degree to which a protein is attracted to a ligand proteolytic activation - correct answer inactive when synthesized in the cell, must chop off one or more portions of the molecule. Requires the presence of a cofactor; attaches to protein and then binding site will become active. cofactors inclue Ca^2+, Mg^2+, Fe^2+, and vits protein hormones and enzymes go thru this allosteric modulators - correct answer binds to protein away from binding site and changes activity; may be inhibitors or activators competition - correct answer antagonists (inhibit)-decrease activity competitive inhibitor - reversible antagonists - competes directly with ligand by binding to active site; eg estrogen receptors blocked to prevent overgrowth/cancer cells irreversible antagonists/inhibitors-do not release agonist (mimic)-competing ligands mimic each other's activity pH and temperature (affects of protein binding) - correct answer Alter 3D shape of protein by disrupting H or S-S bonds; may be irreversible if protein becomes denatured e.g. tyrosinase is temperature sensitive affecting coloring (melanin) of a cat amount of protein - correct answer affects reaction rate; more protein = faster reaction rate regulated by up-regulation or down-regulation of protein synthesis and destruction e.g. check out lanes - cashiers=enzymes amount of ligand - correct answer reaction rate depends on amount of ligand if binding protein (eg an enzyme) is held constant; saturation; eg. glucose transporters in kidney, too much glucose fills receptors isoforms - correct answer different forms of same molecule function is similar but whose affinity for ligands differ from one another eg. hemoglobin in fetus is diff Define bioenergetics and explain the importance and origin of energy in biological systems. - correct answer bioenergetics: energy in biological systems Energy: capacity to do work Metabolism: sum of all chemical reactions in the body Catabo