BICH FINAL EXAM 2024 QUESTIONS LATEST UPDATE 2024/2025 WITH 100% VERIFIED ANSWERS, Exams of Health sciences

Download BICH FINAL EXAM 2024 QUESTIONS LATEST UPDATE 2024/2025 WITH 100% VERIFIED ANSWERS and more Exams Health sciences in PDF only on Docsity! BICH FINAL EXAM 2024 QUESTIONS LATEST UPDATE 2024/2025 WITH 100% VERIFIED ANSWERS The majority of CO2 generated by respiring tissue transported to back to the lungs as bicarbonate How does hemoglobin carry CO2 from the tissues back to the lungs? Carbamoylation of the N-termini as Carbamiminohemoglobin What is the role of His-146 of the β -subunits? -His-146 of the β -subunits binds the proton that regulates the oxygen affinity of hemoglobin producing the Bohr effect. -It forms a disulfide bond with a mutant to stabilize the R-state. World class long distance runners live and train at high altitudes (Park City, Utah) and show up at races located at sea level the day before the event. What is the competitive advantage of this strategy? The lower oxygen concentration in the atmosphere at higher elevations cause the body to adapth by increasing the number or red blood cells and increasing the concentration of hemoglobin molecules in the red blood cells as well as elevating the BPG concentration. The end result is high oxygen carrying capacity which enhances athletic performance, particularly at sea level where the concentration of oxygen is higher. The body will adapt to increased atmospheric oxygen concentrations, so athletes arrive just a day in advance of the event. Cigarette smokers expose themselves to carbon monoxide. What is the effect of carbon monoxide on oxygen transport? How do Cigarette smokers bodies' adjust to accommodate the increased carbon monoxide? Carbon monoxide binds to the irons of hemoglobin diminishing the oxygen carrying capacity of the blood. The body adapts to the diminished oxygen carrying capacity by elevating the BPG concentration in the red blood cells. Some racers in swimming sprints hyperventilate right before the buzzer initiates the race. What are the advantages and disadvantages of the sprinter hyperventilating? By hyperventilating the swimmer saturates his or hemoglobin with oxygen. The disadvantage is raising of the blood pH which in turn increases the oxygen affinity of the hemoglobin delivering less oxygen to the respiring tissues. What happens when a swimmer hyperventilates before the start of the race and holds his or her breath during the swimming sprint. Does the swimmer gain an advantage or disadvantage by this approach? By hyperventilating the swimmer would increase the plasma pH and saturate hemoglobin with oxygen. As he holds his breath and swims, the oxygen concentration and pH decrease. The two effects cancel themselves out for a short period of time. major biological functions of triacylglycerols 1.) Energy source. 2.) Energy storage 3.) Insulation 4.) Generation of Metabolic Water Cellular membranes are self-sealing. What are the properties of membranes that are responsible for this important feature? Hydrophobic interactions are responsible for membrane formation. Membranes are held together by noncovalent interactions so that if the membrane is disrupted the membrane will quickly reseal to avoid exposing the hydrophobic core of the membrane from the aqueous solvent. flippase -primary active transport -maintains conc gradient of 6.6pH in mucosa cell membranes and stomach fluid by pumping H+ out of the mucosa cells in exchange for potassium Secondary Active Transport uses potential energy created by electrochemical gradients of H+, Na+ or K+ -Ex.: sodium linked glucose transporter (SLGT-1) of intestinal epithelium cells is a symport of glucose and Na+ Pore Forming Toxins lethal molecules that insert into host cell membrane and create a pore which collapses the conc gradients and facilitates entry of toxic agents Ex: Ionophors Ionophors facilitate ion transport across plasma membrane either by mobile carriers (Valinomycin) or pores (Gramicidin) Valinomycin -mobile carrier ionophore -several oxygen atoms in center of ring that coordinate to potassium ions and rapidly diffuse across membrane Gramicidin -channel ionophore -linear peptide with 15 residues that can diffuse 10 million K+ ions per second Three Types of Hormones peptide, amino acid derivatives, steroids Peptide Hormones (insulin and glucagon) - water soluble- able to be carried in blood stream Amino Acid Derivatives (histamine and dopamine) - water soluble- able to be carried in blood stream Steroids (derived from cholesterol) - regulate metabolism, electrolyte balance, inflammatory response and sexual function -passively diffuse into nucleus First Messenger Hormone released in blood plasma that binds to a receptor driving a conformational change that produces a response on the cytosolic side Second Messenger Small molecule that changes concentration in response to first messenger. -cAMP, Ca2+, inositol, IP3, DAG -can diffuse into cellular compartments Three types of hormone receptors 7-TMS, 1-TMS, Oligomeric ion channels 7-transmembrane segment (7-TMS) receptors which are integral membrane proteins with seven transmembrane a-helical segments. Examples are the G-binding proteins. single transmembrane segment (1-TMS) catalytic receptors which are proteins that a single transmembrane a-helix that spans the membrane. Examples are tyrosine kinases and guanylate cyclases. Oligomeric ion channels Consist of multiple protein subunits. These channels are also called ligand gated channels because the bind of the hormone to the receptor opens the ion channel. Cholera Toxin ADP-ribosylates via Gs protein to increase cAMP (look at notebook) Pertussis Toxin -burdetella pertusssis is the bacterium that causes whooping cough -affects the regulation of adenylate cyclase Diacylglycerol (DAG) A second messenger produced by phosphoinositide cascade that activates protein kinase C Protein Kinase C -uses ATP to phosphorylate serine and tyrosine residues -binds to DAG and anchors in membrane then the pseudosubstrate sequence interacts with head groups of the phospholipids of the membrane which activates the kinase activity Calcium Binding Proteins Calmodulin: has 4 Ca2+ bound and then is bound by a target protein Collagen triple helix -Found in bone, cartilage, tendons, ligaments, blood vessels ect. -Contains modified amino acids 4-hydroxy proline, 3-hydroxyproline, 5-hydroxylysine. For the collagen triple helix,n= 3.3 amino acids/turnP = 9.9 Å/turn -Glycine every third residue. Every third residue crosses through the two other strands and contacts the crowded center. This residue is always a glycine. Each strand is staggered by one residue. So the center of the helix is all glycines. Silk fibroin -Antiparallel β-sheet. -Alternating glycines (-Gly-Ser-Gly-Ala-Gly-Ala)n Because alternating residues appear on the same side of β−sheets, all the glycines are on one side and the ala and ser residues are on the other. -Silk doesn't stretch because the β−sheets are already fully extended.