BIOCHEMISTRY TOPIC 7 MYOGLOBIN AND HEMOGLOBIN
How many oxygen molecules are bound to hemoglobin when the protein is in the T-state (tense state)? 4 3 2 1 0
Correct answer 0 Feedback Hemoglobin releases oxygen in the T-state and is not bound to any oxygen. When considering the four subunits, all subunits will be in the T-state with no oxygen bound. The correct answer choice is "0".
What is the number of oxygen molecules that must bind in order for hemoglobin to shift to the R-state (relaxed state)? 0 1 2 3 4
Correct answer 1 Feedback Hemoglobin's structure changes from T to R-state upon binding of one oxygen molecule. The correct answer choice is "1".
Carbon monoxide is poisonous because the ability of carbon monoxide to bind to hemoglobin is ___________ than the ability of oxygen to bind to hemoglobin. 20 times lower 200 times lower 200 times greater 20 times greater
Correct answer 200 times greater Feedback Carbon monoxide is toxic because hemoglobin prefers to bind carbon monoxide over oxygen. This is due to hemoglobin's increased affinity for carbon monoxide. Hemoglobin's affinity for carbon monoxide is 200 times greater than hemoglobin's affinity for oxygen. The correct answer choice is "200 times greater".
Structurally, hemoglobin can bind ___ molecules of oxygen, all of which could potentially be replaced by carbon monoxide. 1 3 4 2
Correct answer 4 Feedback Binding of one carbon monoxide molecule changes the conformation of the hemoglobin in a fashion such that more molecules of carbon monoxide can bind to the same protein. The correct answer is "positive cooperativity".
Why is more oxygen unloaded from hemoglobin in an actively metabolizing tissue than in a resting tissue, even at the same PO2? At the lower pH of an actively metabolizing tissue, hemoglobin has a lower affinity for oxygen. Hemoglobin binds four oxygen molecules due to a shape change caused by the lower pH of active tissues. More oxygen is bound to myoglobin at lower oxygen concentrations. More carbon dioxide is drawn out of tissue cells as it is converted to biocarbonate in red blood cells.
Correct answer At the lower pH of an actively metabolizing tissue, hemoglobin has a lower affinity for oxygen. Feedback When tissues are actively performing metabolic processes, carbon dioxide is produced. Carbon dioxide combines with water to produce H+ and bicarbonate. The increase in H+ causes a decrease in pH and a decrease in hemoglobin's affinity for oxygen. The correct answer choice is "At the lower pH of an actively metabolizing tissue, hemoglobin has a lower affinity for oxygen."
Which of the following does not bind directly to hemoglobin? O2 CO CO2 H+ 2,3 BPG
Correct answer CO2 Feedback Carbon dioxide does not bind directly to hemoglobin, whereas oxygen, carbon monoxide, H+ and 2,3-BPG are all able to bind directly to the protein.
Why is the oxygen binding curve in hemoglobin sigmoidal? Carbon monoxide poisoning The non-planar heme conformation Cooperativity Competitive binding
Correct answer Cooperativity Feedback The oxygen binding curve of hemoglobin is sigmoidal because of cooperativity. Once one oxygen molecule binds hemoglobin, there is a steep slope in the curve due to the remaining three protein subunits' ability to bind oxygen easily. The correct answer choice is "Cooperativity".
Patients with carbon monoxide (CO) poisoning may exhibit pink or cherry red skin, mucus membranes and nails. Which statement accurately describes hemoglobin's role in CO poisoning? Hemoglobin binds to CO with a lower affinity than oxygen and stabilizes the R-state. Hemoglobin binds to CO with a higher affinity than oxygen and stabilizes the T-state. Hbinds to CO with a higher affinity than oxygen and stabilizes the R-state. Hemoglobin binds to CO with a lower affinity than oxygen and stabilizes the T-state.
Correct answer H binds to CO with a higher affinity than oxygen and stabilizes the R-state. Feedback Hemoglobin binds 200-times more strongly to CO than oxygen and When CO binds to hemoglobin, it stabilizes the R-state of the protein. The R state of hemoglobin is responsible for the pink or cherry red color observed in CO poisoning. The correct answer choice is "Hemoglobin binds CO with a higher affinity than oxygen and stabilizes the R-state."
Which of the following also describes an "Acidic" condition? (Select all that apply) low pH high pH low H+ high H+ low protons high protons
Correct answer low pH high H+ high protons Feedback Acidic, low pH, high H+ and high protons all describe the same aqueous environment.
Which of the following is accurate for hemoglobin and myoglobin? Hemoglobin and myoglobin bind oxygen directly on an iron atom located inside of a heme group. Hemoglobin and myoglobin have similar quaternary structures. Hemoglobin and myoglobin bind oxygen in a cooperative manner. Hemoglobin and myoglobin deliver oxygen in response to the Bohr effect.
Correct answer Hemoglobin and myoglobin bind oxygen directly on an iron atom located inside of a heme group. Feedback Hemoglobin and myoglobin both contain an iron atom and heme group. Oxygen binds to the iron atom in both proteins. The correct answer choice is "Hemoglobin and myoglobin bind oxygen directly on an iron atom located inside of a heme group.".
Which of the following corresponds to the Relaxed state (R state)? Hemoglobin binds oxygen at high pH. Hemoglobin binds oxygen at low pH. Hemoglobin releases oxygen at high pH. Hemoglobin releases oxygen at low pH.
Correct answer Hemoglobin binds oxygen at high pH. Feedback Feedback Hemoglobin binds oxygen at a high pH (in the lungs) and when oxygen is bound, hemoglobin is in the R-state.The correct answer choice is "Hemoglobin binds oxygen at high pH".
Which of the following statements accurately describes cooperativity? Myoglobin can bind subsequent molecules of oxygen more easily after the first oxygen molecule binds. Myoglobin and hemoglobin work together to deliver oxygen to the tissues. Hemoglobin can bind subsequent molecules of oxygen more easily after the first oxygen molecule binds. Oxygen and carbon dioxide exchange occurs in the alveoli of the lungs.
Correct answer Hemoglobin can bind subsequent molecules of oxygen more easily after the first oxygen molecule binds. Feedback Cooperativity only occurs with proteins with quaternary structure (multiple polypeptide chains). Hemoglobin has four subunits (polypeptide chains) and can bind up to four oxygen molecules. As each oxygen binds hemoglobin, the affinity of hemoglobin for oxygen increases. Increased affinity is caused by a conformational change, or a structural change in hemoglobin. Because myoglobin has only one subuint (one polypeptide chain), myoglobin cannot exhibit cooperativity. The correct answer choice is "Hemoglobin can bind subsequent molecules of oxygen more easily after the first oxygen molecule binds.".
Hemoglobin transports oxygen and myoglobin stores oxygen. They exhibit different oxygen binding curves when plotted on a graph with total partial pressure of the oxygen (x-axis) plotted against the percent saturation of hemoglobin (y-axis). What is the shape of the oxygen binding curves for hemoglobin and myoglobin? Hemoglobin has a sigmoidal curve, whereas myoglobin has a hyperbolic curve Myoglobin has a sigmoidal curve, whereas hemoglobin has a hyperbolic curve Both have a sigmoidal curve Both have a hyperbolic curve
Correct answer Hemoglobin has a sigmoidal curve, whereas myoglobin has a hyperbolic curve Feedback Since hemoglobin binds oxygen in a cooperative manner, it has a sigmoidal curve, whereas myoglobin only binds one molecule of oxygen, so it has a hyperbolic curve. The correct answer choice is "Hemoglobin has a sigmoidal curve, whereas myoglobin has a hyperbolic curve.".
Which of the following is associated with cooperativity? The increased affinity for oxygen that myoglobin has when oxygen concentration is low The ability of hemoglobin to supply the RBC with oxygen for ATP production The exchange of oxygen that happens in the placenta between maternal and fetal blood Hemoglobin structural changes that increase its affinity for oxygen
Correct answer Hemoglobin structural changes that increase its affinity for oxygen Feedback Cooperativity is the process by which hemoglobin structural changes increase its affinity for oxygen molecules to bind. Myoglobin, containing only tertiary structure (one polypeptide chain) cannot undergo cooperativity. The correct answer choice is "Hemoglobin structural changes that increase its affinity for oxygen".
Which of the following accurately describes the functions of hemoglobin and myoglobin? Hemoglobin transports oxygen, Myoglobin stores oxygen. Hemoglobin stores oxygen, Myoglobin transports oxygen.
Correct answer Hemoglobin transports oxygen, Myoglobin stores oxygen. Feedback Incorrect. If you chose this option, it is incorrect because the function of hemoglobin is to transport oxygen while the function of myoglobin is to store oxygen. The correct option is "Hemoglobin transports oxygen, Myoglobin stores oxygen".
In which of the following patients is the planar conformation of the heme group in hemoglobin favored? In a girl with diabetic ketoacidosis In a firefighter who is brought to the emergency room after entering a burning building In an older woman with pneumonia and sepsis who has a blood pH of 7.1 In the muscle capillaries of a patient who is on a treadmill for a cardiac stress test
Correct answer In a firefighter who is brought to the emergency room after entering a burning building Feedback The planar conformation of heme would be favored under conditions of high pH (at high pH, hemoglobin prefers to bind oxygen and heme is in the planar conformation). A hospitalized firefighter would presumably be receiving oxygen and would thus have more hemoglobin in the oxygen binding conformation. The correct answer choice is "In a firefighter who is brought to the emergency room after entering a burning building".
Hemoglobin and myoglobin proteins bind molecular oxygen. The protein subunit of hemoglobin does not bind directly to the oxygen. Instead, a specific atom binds oxygen. In hemoglobin, which of the following will directly bind oxygen? Histidine Heme Carbon Monoxide Iron
Correct answer Iron Feedback Hemoglobin contains a heme group, which contains an iron atom. Oxygen binds directly to the iron atom in the heme group. The correct answer choice is "iron".
Myoglobin stores oxygen, whereas hemoglobin transports oxygen. Which of the following statements accurately describes the affinity of myoglobin and hemogobin for oxygen? Hemoglobin and myoglobin both have the same affinity for oxygen. Hemoglobin has a higher affinity for oxygen compared to myoglobin. Myoglobin has exactly one-quarter of the affinity for oxygen because it has only one subunit. Myoglobin has a higher affinity for oxygen compared to hemoglobin.
Correct answer Myoglobin has a higher affinity for oxygen compared to hemoglobin. Feedback Since myoglobin stores oxygen, it has a higher affinity for oxygen. Hemoglobin's lower affinity for oxygen allows hemoglobin to release oxygen to the tissues at a lower blood pH. The correct answer choice is "Myoglobin has a higher affinity for oxygen compared to hemoglobin."
Why is the oxygen binding curve for myoglobin hyperbolic? Myoglobin has four subunits. Myoglobin binds oxygen in a cooperative manner. Myoglobin has similar tertiary structure as hemoglobin. Myoglobin has one subunit.
Correct answer Myoglobin has one subunit. Feedback Myoglobin has only one protein subunit, thus it is not capable of undergoing cooperativity so it exhibits a hyperbolic oxygen binding curve.The correct answer choice is "myoglobin has one subunit".
Why is myoglobin incapable of exhibiting cooperativity? Myoglobin has only one subunit and can only bind one molecule of oxygen. Myoglobin binds four molecules of oxygen. Myoglobin delivers oxygen to metabolizing tissues. Myoglobin adopts the R-state when it binds to oxygen.
Correct answer Myoglobin has only one subunit and can only bind one molecule of oxygen. Feedback Myoglobin does not exhibit cooperativity because it only has one subunit and only binds to one oxygen molecule. The correct answer choice is "Myoglobin has only one subunit and can only bind one molecule of oxygen."
Which of the following is associated with myoglobin? Cooperativity Four oxygen molecules One heme group Two subunits
Correct answer One heme group Feedback Myoglobin has one subunit, one heme group, one iron atom and binds one oxygen molecule. The correct option is "One heme group".
Myoglobin and hemoglobin each have different numbers of subunits and this affects their respective oxygen storage and delivery capabilities. How many subunits does myoglobin have versus hemoglobin? One, Four Two, Three One, Two Four, One
Correct answer One, Four Feedback Myoglobin has one subunit and hemoglobin has four subunits. The correct answer choice is "One, Four".
Identify the image that corresponds to the T (tense) state. Option 1 Option 2
Correct answer Option 2 Feedback Hemoglobin releases oxygen when it is in the tense state. In the tense state, the heme group is bent/non-planar.
When binding hemoglobin or myoglobin, CO binds in place of _________. Histidine Heme Iron Oxygen
Correct answer Oxygen Feedback Carbon monoxide binds to hemoglobin in place of oxygen, which is what makes carbon monoxide toxic.The correct answer is "oxygen".
Which of the following components can bind directly to the iron atom in hemoglobin? (select all that apply) heme Oxygen CO CO2
Correct answer Oxygen CO Feedback Oxygen and carbon monoxide are able to bind directly to the iron group in hemoglobin. The correct answer choices are "oxygen" and "CO".
Hemoglobin's cooperative binding behavior is key to its physiological function. The binding of which of the following molecules influences this behavior? Oxygen Heme Iron None of these
Correct answer Oxygen Feedback The binding of oxygen to hemoglobin makes it easier for subsequent oxygen molecules to bind to hemoglobin in cooperativity. The correct answer choice is "oxygen".
Even though the amino acid sequence between subunits of hemoglobin and myoglobin are not exactly the same, there are other similarities between the two proteins. Which level of protein structure differs when comparing myoglobin to hemoglobin? Primary Secondary Tertiary Quaternary
Correct answer Quaternary Feedback Quaternary structure is not found in both proteins. Myoglobin only has one subunit, so it has tertiary structure, but no quaternary structure. Hemoglobin has four subunits and thus has quaternary structure. The correct answer choice is "Quaternary".
Oxygen binding alters the structure of an entire hemoglobin tetramer, so the structures of oxyhemoglobin and deoxyhemoglobin are noticeably different. The oxyhemoglobin conformation is specifically referred to as the __________ state, whereas the deoxyhemoglobin conformation is referred to as the __________ state. Oxygenated and Deoxygenated O and D Relaxed and Tense There is no difference between the two states
Correct answer Relaxed and Tense Feedback Oxygenated hemoglobin is in the R-state, deoxygenated hemoglobin is in the T-state. The correct answer choice is "Relaxed, Tense".
2,3 BPG stabilizes the _____ state(s) of hemoglobin. T R and T R None of the options are correct
Correct answer T Feedback 2,3-BPG stabilizes the T-state of hemoglobin and facilitates the release of oxygen. The correct answer choice is "T".
What conformation of hemoglobin is stabilized when it binds to 2,3-BPG? R-state T-state Acidic Basic
Correct answer T-state Feedback When 2,3-BPG binds hemoglobin, it stabilizes the T-state and favors the release of oxygen. The correct answer choice is "T-state".
Acidosis occurs as a result of cardiac arrest. Which of the following is the theoretical reason why sodium bicarbonate might be administered to your patient during a cardiac arrest? The bicarbonate acts to decrease pH, which enables hemoglobin to enter the T state and more effectively deliver oxygen to the tissues. The bicarbonate acts to decrease pH, which enables hemoglobin to enter the lung and resume binding to oxygen. The bicarbonate acts to increase pH, which may allow hemoglobin to transport oxygen more efficiently. The bicarbonate acts to increase pH, prompting hemoglobin to shift to the R state and pick up CO2 that has accumulated during the cardiac arrest.
Correct answer The bicarbonate acts to increase pH, which may allow hemoglobin to transport oxygen more efficiently. Feedback The addition of bicarbonate will increase pH, which alleviates the acidosis caused by the cardiac arrest. A differential (high versus low) in pH levels is needed for hemoglobin to effectively transport oxygen in the body. The correct answer choice is "The bicarbonate acts to increase pH, which may allow hemoglobin to transport oxygen more efficiently."
Which of the following statements accurately associates the H+ ion concentration and carbon dioxide concentration with hemoglobin's affinity for oxygen? When carbon dioxide levels are high and the H+ concentration is low, hemoglobin prefers to release to oxygen. When carbon dioxide levels are high and the H+ concentration is high, hemoglobin prefers to bind to oxygen. When carbon dioxide levels are low and the H+ concentration is low, hemoglobin prefers to release oxygen. When carbon dioxide levels are low and the H+ concentration is low, hemoglobin prefers to bind to oxygen.
Correct answer When carbon dioxide levels are low and the H+ concentration is low, hemoglobin prefers to bind to oxygen. Feedback Hemoglobin binds oxygen in the lungs, when pH is high, H+ concentration is low and the concentration of carbon dioxide is low. The correct answer choice is "When carbon dioxide levels are low and the H+ concentration is low, hemoglobin prefers to bind to oxygen.".
Addition of ______________________alters the shape of the iron-heme complex, and therefore its absorption of light as indicated by its color change from dark purple (the color of hemoglobin in venous blood) to brilliant scarlet (the color of hemoglobin in arterial blood). globin subunit iron oxygen porphyrin
Correct answer oxygen Feedback Oxygenated blood is scarlet red. This is why veins and arteries are different colors. The correct answer choice is "oxygen".
The symptoms of sickle cell anemia are primarily because red blood cells are misshaped. Which of the following is associated with the cause of sickle cell anemia? a mutation in the beta hemoglobin gene, which leads to insertion of glutamate into the hydrophobic patches of oxygenated hemoglobin. a mutation in the alpha hemoglobin gene, which leads to insertion of valine into the hydrophobic patches of deoxygenated hemoglobin. a mutation in the alpha hemoglobin gene, which leads to insertion of valine into the hydrophobic patches of oxygenated hemoglobin. a mutation in the beta hemoglobin gene, which leads to insertion of valine into the hydrophobic patches of deoxygenated hemoglobin.
Correct answer a mutation in the beta hemoglobin gene, which leads to insertion of valine into the hydrophobic patches of deoxygenated hemoglobin. Feedback In Sickle Cell Anemia, the beta hemoglobin gene contains a mutation that changes glutamate to valine, which affects the hydrophobic patches of deoxygenated hemoglobin. Glutamate is a polar amino acid. When valine, a nonpolar amino acid, is substituted in its place, this leads to aggregation of hemoglobin under low oxygen concentrations. The correct answer choice is "a mutation in the beta hemoglobin gene, which leads to insertion of valine into the hydrophobic patches of deoxygenated hemoglobin."
Which of the following facilitates the transition of hemoglobin from the R state to the T state? a scarcity of 2,3-BPG an increase in the concentration of H+ an increase in CO. a decrease in CO2.
Correct answer an increase in the concentration of H+ Feedback Hemoglobin switches from the R-state to the T-state when it is ready to release oxygen. Hemoglobin releases oxygen when H+ concentration is high and the pH level is low. The correct answer choice is "an increase in concentration of H+".
In the deoxygenated state the Heme is ____________, where as in the oxygenated state, the heme is _____________________. planar, planar planar, bent (non-planar) bent (non-planar), planar bent (non-planar), bent (non-planar)
Correct answer bent (non-planar), planar Feedback Deoxygenated heme has a bent shape, while oxygenated heme has a planar shape. The correct answer choice is "bent (nonplanar), planar".
When the blood pH is low, the heme is in_______________ shape. When the blood pH is high, the heme is in ______________shape. planar, bent (non-planar) bent (non-planar), bent (non-planar) bent (non-planar), planar planar, planar
Correct answer bent (non-planar), planar Feedback When pH is low, hemoglobin prefers to release oxygen, which causes the heme to be in the bent conformation. When pH is high, hemoglobin prefers to bind oxygen, which causes heme to be in the planar conformation. The correct answer choice is "bent (non-planar), planar".
The structure of fetal hemoglobin allows it to have a higher affinity for oxygen when compared to maternal hemoglobin. Which of the following accurately describes fetal hemoglobin? binds oxygen tightly at lower oxygen concentrations identical polypeptide chains as adult hemoglobin is never in the R-state exhibits an oxygen binding curve that is the same shape as myoglobin oxygen binding curve
Correct answer binds oxygen tightly at lower oxygen concentrations Feedback Fetal hemoglobin is preferentially in the R-state and is capable of binding oxygen at lower oxygen concentrations. This allows fetal hemoglobin to receive oxygen from maternal hemoglobin. The correct answer choice is "binds oxygen at lower oxygen concentrations".
Carbonic anhydrase is an important __________ present in the red blood cells that aids in efficient transportation of carbon dioxide in the form of _________, from tissues to lungs. enzyme, carbon dioxide substrate, bicarbonate ions enzyme, bicarbonate ions chemical, carbon monoxide
Correct answer enzyme, bicarbonate ions Feedback Carbonic anhydrase is an enzyme (its name ends with -ase) and it allows carbon dioxide to travel to the lungs in the form of bicarbonate, since carbon dioxide itself does not travel through the blood. The correct answer choice is "enzyme, bicarbonate ions".
Carbon monoxide outcompetes oxygen for attachment to the __________ group of hemoglobin where it is permanently, covalently attached. heme ligand sulfide histidine
Correct answer heme Feedback Carbon monoxide and oxygen bind hemoglobin by binding to the heme group at the center of the protein. The correct answer is "heme".
When hemoglobin changes from T to R, it has ________ affinity for oxygen. zero high low none of these are correct
Correct answer high Feedback Hemoglobin has a high affinity for oxygen and prefers to bind oxygen, when it is in the R-state. The correct answer choice is "high".
Which of the following also describes an "basic" condition? (Select all that apply) low pH high pH low H+ high H+ low protons high protons
Correct answer high pH low H+ low protons Feedback Basic, high pH, low H+ and low protons all describe the same aqueous environment.
Patients with sickle cell anemia have atypical hemoglobin, which will distort the red blood cells into sickle shape during oxygen delivery. The substitution of a hydrophilic amino acid with a ____________amino acid in hemoglobin subunits results in the polymerization of hemoglobin, leading to the sickling of red blood cells. polar cysteine hydrophilic hydrophobic
Correct answer hydrophobic Feedback In Sickle Cell Anemia, the beta hemoglobin gene contains a mutation of glutamate to valine (a hydrophobic amino acid), which affects the hydrophobic patches of deoxygenated hemoglobin. The correct answer choice is "hydrophobic".
Carbon monoxide binds to the __________ in hemoglobin. The binding of carbon monoxide is ________ than the the binding of oxygen in hemoglobin. iron, stronger phosphate, stronger iron, weaker phosphate, weaker
Correct answer iron, stronger Feedback Carbon monoxide binds to the iron atom within the heme group of hemoglobin. The binding of carbon monoxide is stronger than the binding of oxygen to hemoglobin. The correct answer choice is "iron, stronger".
Which of the following is associated with carbon monoxide poisoning? (check all that apply) it stabilizes the R state of hemoglobin it stabilizes the T state of hemoglobin it increases hemoglobin's affinity for O2 it decreased hemoglobin's affinity for O2 it binds to hemoglobin with a higher affinity than O2
Correct answer it stabilizes the R state of hemoglobin it increases hemoglobin's affinity for O2 it binds to hemoglobin with a higher affinity than O2 Feedback When carbon monoxide binds hemoglobin, it stabilizes the R-state of hemoglobin and binds to hemoglobin with a higher affinity than oxygen. It also increases the hemoglobin's affinity for oxygen, however, since carbon monoxide locks hemoglobin in the R-state, the oxygen is not released. The correct answer choices are "it stabilizes the R state of hemoglobin", "it increases hemoglobin's affinity for O2" and "it binds to hemoglobin with a higher affinity than O2".
Which of the following favor the oxygenated form of hemoglobin? (select all that apply) planar heme group high CO2 Relaxed state high pH high H+ 2,3-BPG
Correct answer planar heme group Relaxed state high pH Feedback When hemoglobin binds oxygen, it is in the R-state and heme is the planar conformation. Hemoglobin binds oxygen in the lungs, where pH is high. The correct answer choices are "planar heme group, relaxed state, high pH".
As carbon monoxide binds to hemoglobin, the protein subunits change conformation to allow carbon monoxide to bind faster. This process is called __________. non-competitive inhibition allosteric binding positive cooperativity competitive inhibition
Correct answer positive cooperativity Feedback Binding of one carbon monoxide molecule changes the conformation of the hemoglobin in a fashion such that more molecules of carbon monoxide can bind to the same protein. The answer choice is "positive cooperativity".
What level of protein structure does hemoglobin have that is not found in myoglobin? primary secondary tertiary quaternary
Correct answer quaternary Feedback Hemoglobin has quaternary structure because it has four subunits, but myoglobin only has tertiary structure because it only has one subunit.
Hemoglobin's structure allows it to bind oxygen in the lungs. Which of the following accurately describe hemoglobin's structure in the lungs? (Choose all that apply) Hemoglobin is in the R state. The heme group is planar. The subunits are further apart from one another than they are in the deoxygenated state. The subunits are closer together than they are in the deoxygenated state.
Correct answers Hemoglobin is in the R state. The heme group is planar. The subunits are closer together than they are in the deoxygenated state. Feedback Since Hemoglobin binds oxygen in the lungs, it is the R state, the heme group is planar and the subunits are closer together. As hemoglobin approaches the tissues, hemoglobin will shift from the R state to the T state where it will release oxygen. The correct answer choices are "Hemoglobin is in the R state.", "The heme group is planar." and "Hemoglobin's subunits are closer together than they are in the deoxygenated state.".
Which of the following stabilizes the T state of hemoglobin? (Choose all that apply.) Low pH High pH 2, 3 - BPG Carbon monoxide
Correct answers Low pH 2, 3 - BPG Feedback When hemoglobin approaches the tissues, where the pH is low, hemoglobin will shift from the R state to the T state. Also, the binding of 2,3-BPG stabilizes the T-state of the hemoglobin. The correct answer choices are "low pH" and "2,3 BPG".
Hemoglobin acts as a buffer and controls the pH of the blood by binding __________. oxygen bicarbonate ion H+ ions carbon dioxide
Corrrect answer H+ ions Feedback Hemoglobin can regulate pH by binding to H+. The correct answer choice is "H+ ions."
