Bios 1300 Exam 2| Latest Questions And Answers

BIOS 1300 Exam 2| LATEST QUESTIONS AND ANSWERS All organisms are composed of what? - Cells Why is there an upper limit on cell size? - Cells lose their ability to support themselves What does the plasma membrane divide? - The fluid within a cell; intracellular fluid from extracellular fluid What is a phospholipid? - Amphipathic molecules arranged in a bilayer Where do the phosphate heads face? - Face water on either side of the membrane Where do the tails face and what kind of tail is it? - Are in the center; hydrophobic What percent of the membrane are lipids? - 75% What does cholesterol increase? - Membrane integrity What percent is cholesterol? - 20% What percent is gycolipids? - 5% Where do gycolipids face? - Face the extracellular How much of the membrane molecules are comprised of proteins? - Comprise a small amount, but half its weight What do integral proteins do? - Penetrate the membrane depending on which portion of the protein is hydrophilic & hydrophobic Does a transmembrane protein pass completely through the membrane? - Yes What are bound to glycoproteins? - Carbohydrates What do the peripheral proteins adhere to? - Adhere to one face of the membrane What are the peripheral proteins bound to? - Cytoskeleton What does a receptor do? - Binds to chemical messengers such as hormones sent by other cells What does an enzyme do? - Breaks down a chemical messenger and terminates its effect What is a channel? - Channel protein that is constantly open and allows solutes to pass into and out of cell What are gated channels? - Gates that opens and closes to allow solutes through only at certain times What is a cell-identity marker? - Glycoprotein acting as a cell-identity marker distinguishing the body's own cells from foreign cells What is a cell-adhesion molecule (CAM)? - Cell-adhesion molecule (CAM) that binds one cell to another What is glycocalyx - A "fuzzy" coat external to the plasma membrane created by the carbohydrate portions of glycoproteins and glycolipids What are glycocalyx functions? - Immunity, transplant compatibility, cell adhesion, and fertilization What are microvilli? - Short membrane extensions which increase the surface area of absorptive cells What are cilia? - Long membrane extensions which serve sensor or motility functions What do primary cilium monitor? - Monitors nearby conditions and its important in various sensory organs Where are motile cilia found? - Found in greater number on cells of the respiratory tract, reproductive tract, and brain to unindirectionally sweep materials across the cell surface What are motile cilia comprised of? - Comprised of 9 + 2 organization of microtubules called axoneme Using ______, _____ arms "crawl" up the adjacent microtuble, bending the cilium - ATP; dyneim Where do cilia anchor? - Anchor to the cell at the basal body Where does cilia beat and help do what? - Beat within a saline layer on the surface of cells and help to move mucus Chloride pumps move chloride into the ECF and what follows? - Sodium and water What is Cystic Fibrosis? - Hereditary disease in which cells make Cl- pumps, fail to place them in the plasma membrane, & create an inadequate saline layer What blocks the pancreatic ducts and respiratory tract and what does it result in? - Mucus plugs; resulting in inadequate digestion and respiratory infections What is the life expectancy of cystic fibrosis? - 35 years What are the only human cells that have functional flagellum? - Sperm What is flagellum? - Much longer than a cilium, but identical axoneme structure; movement not in strokes, but undulating or corkscrew What are pseudopods? What can they be used for? - Continually changing cell extensions which vary in shape and size; Locomotion or capturing foreign particles What is the plasma membrane? - Selectively permeable, only allowing some particles pass through Passive mechanisms occur without what? What do they include? - ATP input; Filtration, diffusion, and osmosis What do active mechanisms consume? What do they include? - ATP; Active transport and vesicular transports What happens during filtration? - Particles are driven through membranes by physical pressure What forces water and small solutes (salts) through narrow clefts between capillary cells? - Blood pressure What does the cleft hold back? - Large particles such as cells What is simple diffusion? - The movement of particles from areas of higher to lower concentration Does simple diffusion require a membrane? - No Substances only diffuse through a membrane if what? - If the membrane is permeable to that substance How does temperature affect the rate of diffusion? - Increase temperature causes increased molecular motion How does molecular weight affect the rate of diffusion? - Large molecules move slower How does the difference in concentration affect the rate of diffusion? - Bigger difference increases rate How does membrane surface area affect the rate of diffusion? - Increased area increases rate How does membrane permeability affect the rate of diffusion? - Increased permeability increases rate What is osmosis? - The diffusion of water through a selectively permeable membrane What will solutes particles which cannot pass through the membrane cause? - Water to diffuse from the opposite side of the membrane What is osmosis important in consideration for? - I.V. fluid, diarrhea diseases, edema, and viral infections What are aquaporins and what do they allow? - Channel proteins; allow water to pass more quickly through a membrane What is hydrostatic pressure? - Pressure of a liquid; opposes osmotic pressure What is reverse osmosis? - The process of applying mechanical pressure to What is osmolariity? - A measure of the number of osmoles per liter of solution What is one osmole equal to? What does it take into account? - Equal to one mole of dissolved particles; ionization What is the osmolarity of body fluids? - 300mosm; total concentration of all solutes within it What is the number five cause of death world wide and is tied with HIV and AIDS? - Diarrhea and dysentery (bloody diarrhea) How many deaths do diarrhea and dysentery cause? - 1.5 million deaths Who most commonly gets diarrhea and dysentery and why? - Children under the age of five; have more vulnerable because they have a high metabolic rate (higher urine excretion), kidneys which cannot concentrate urine as well, and more cutaneous evaporation What does tonicity describe? - Describes the ability of a solution to affect he fluid volume and pressure in a cell What does hypotonic solution cause? - Causes a cell to absorb fluid and swell; more solutes intracellular What does isotonic solution cause? - Causes no change in cell volume What does hypertonic solution cause? - Causes a cell to lose fluid and shrivel; more solutes extracellular What do transport proteins do? - Carry solutes into or out of cells or their organelles What is transport maximum? - Rate at which all carriers are occupied What is uniport? - carry one type of solute What is symport? - Cotransport; two solutes simultaneously in the same direction What is antiport? - Countertransport; two or more solutes in opposite directions What is facilitated diffusion? - Carriers move solutes down their concentration gradient, do not use ATP What does primary active transport do? - Move solutes up their concentration gradient, using ATP for energy What does the sodium potassium pump do? - Balances the concentration of Na+ and K+ in body fluids; regulates solute concentration, osmosis, and cell volume; maintains negative resting membrane potential; produces heat What does the seco