WGU785 Biochemistry Final Exam Questions
And Answers Verified 100% Correct
Explain Carbon Monoxide's affinity for hgb.
ANSWER- CO binds to the same group as oxygen, but binds more strongly. If CO is
there, it will pick up the O2 but it will not drop it off. This is why CO poisoning is so
harmful. The pt will be very pink in color. CO stabilizes the R-state by binding to the
same iron in Hgb and changing the heme shape.
Describe fetal 2,3 BPG and oxygen affinity.
ANSWER- The fetus has a higher affinity for oxygen than mom. The mother's 2,3
BPG is higher so their afinity for oxygen is lower. The mom becomes deoxygenated.
Affinity-stickiness for oxygen.
How is a HGB structure affected by the absence of oxygen?
ANSWER- The structure becomes tense. The heme is dome shaped. pH will be
lower. This is found in the muscles.
Describe Hemoglobin
ANSWER- 1. Low affinity for oxygen.
2. Transports oxygen to the tissues.
3. Acts as a buffer and controls pH by binding to H+ ions.
4. 4 protein, 4 Iron/Heme, 4 Oxygen
5. Binds to oxygen at high pH and releases at low pH
6. High affinity for CO
7. Quarternary structure
Describe Myoglobin
ANSWER- 1. High affinity for oxygen
2. Stores oxygen in muscle and releases it when oxygen levels get low
3. Not affected by change in pH
4. 1 protein, 1 iron/heme, 1 oxygen
5. Tertiary structure
How does pH influence the oxygen saturation of hemoglobin?
ANSWER- Left shift: increased affinity for oxygen, increased pH (acidic), weak bond
Right shift: decreased affinity for oxygen, decreased pH, strong bond
Bohr Effect: increase in pH->increased affinity for oxygen->increased Hgb saturation-
>reach 100% sooner. Oxygen will be distributed better, delivering more or less where
,we need it.
Cholesterol
ANSWER- 1. 4 Ring structure
2. AKA sterols (cholesterol, cortisol, testosterone)
3. Needed for membrane fluidity (expansion)
4. Increases temp to solidify
5. Needed to synthesize Vitamin D in the skin, cholic acid (component of bile), and
steroid hormones.
Steroid Hormones
ANSWER- synthesized by cholesterol;
testosterone and estrogen-promote growth and development of sex characteristics;
cortisol-released in response to stress and promotes glucose synthesis in liver.
How could myoglobin indicate an MI?
ANSWER- Myoglobin is a protein with a single subunit containing both heme and
iron. While myoglobin is normally contained only in the muscles, it can be released into
the bloodstream if there is muscle damage. For this reason, measuring the levels of
myoglobin in the blood can provide evidence of rhabdomyolysis, a mild heart attack, or
a muscular degenerative disease.
Describe the Anabolic/Anaerobic Pathway.
ANSWER- Occurs when there is no oxygen. The ETC cannot work. Requires energy to
synthesize larger molecules.
NAD+ runs out->fermentation regenerates the NADH to NAD+ ->small amounts of ATP
and lactate are made->Cori Cycle in liver
*Ends in -GENESIS-*
Describe the Catabolic Pathway.
ANSWER- generates energy by breaking down larger molecules.
*Ends in -LYSIS-*
What do the Anabolic and Catabolic pathways have in common?
ANSWER- They are both required for maintaining the cell's energy balance.
Describe the Cori Cycle.
ANSWER- The Cori Cycle is part of the anabolic pathway. It uses the lactate
made by fermentation in the liver and uses gluconeogenesis to convert 2 lactate to
, glucose. 2 ATP are made with each cycle, but it uses 6. The net loss is -4 ATP.
Describe fermentation.
ANSWER- Fermentation is the formation of lactate by regenerating the NAD+ from
NADH that was used during glycolysis to make small amounts of ATP and lactate. It
allows glycolysis to continue in the absence of oxygen.
What does the Cori Cycle supply for red blood cells?
ANSWER- The Cori Cycle supplies glucose for RBCs.
The Cori Cycle takes up lactate from the blood and uses the gluconeogenesis pathway
to convert 2 molecules of lactate back to glucose. As the byproduct of anaerobic
glycolysis, lactate diffuses into the blood and is taken up by the liver where it is
converted back into pyruvate by the enzyme dehydrogenase. The newly formed
glucose is released into the blood to be used again for energy by the red blood cells
and muscles.
Because there is no oxygen present during the Cori Cycle, pyruvate from glycolysis is
converted to lactate. What happens to this lactate?
ANSWER- The lactate made from glycolysis is put into the blood. The liver picks up the
lactate and uses gluconeogenesis to convert 2 molecules of lactate into glucose.
Which molecule starts the citric acid cycle?
ANSWER- Acetyl-coA.
Describe the Citric Acid Cycle.
ANSWER- AKA Kreb's Cycle.
Takes in Acetyl CoA, NAD, FAD, and GDP.
Puts out CO2, NADH, FADH2, and GTP.
Takes place in mitrochondria.
A defect in this cycle will cause low levels of ATP.
It can be inhibited by increased levels of NADH d/t feedback inhibition.
What is needed in the Citric Acid Cycle to continue aerobic metabolism?
ANSWER- NADH and FADH2
What is the effect of glucagon on carbohydrate metabolism?
ANSWER- Converts glucose into glycogen for later use during hyopoglycemia.
Glycogenesis: the formation of glycogen from sugar.
If oxygen is scarce (anaerobic conditions, ie: exercise), what happens to pyruvate?
ANSWER- Pyruvate will be reduced via an anaerobic pathway by the addition of 2
And Answers Verified 100% Correct
Explain Carbon Monoxide's affinity for hgb.
ANSWER- CO binds to the same group as oxygen, but binds more strongly. If CO is
there, it will pick up the O2 but it will not drop it off. This is why CO poisoning is so
harmful. The pt will be very pink in color. CO stabilizes the R-state by binding to the
same iron in Hgb and changing the heme shape.
Describe fetal 2,3 BPG and oxygen affinity.
ANSWER- The fetus has a higher affinity for oxygen than mom. The mother's 2,3
BPG is higher so their afinity for oxygen is lower. The mom becomes deoxygenated.
Affinity-stickiness for oxygen.
How is a HGB structure affected by the absence of oxygen?
ANSWER- The structure becomes tense. The heme is dome shaped. pH will be
lower. This is found in the muscles.
Describe Hemoglobin
ANSWER- 1. Low affinity for oxygen.
2. Transports oxygen to the tissues.
3. Acts as a buffer and controls pH by binding to H+ ions.
4. 4 protein, 4 Iron/Heme, 4 Oxygen
5. Binds to oxygen at high pH and releases at low pH
6. High affinity for CO
7. Quarternary structure
Describe Myoglobin
ANSWER- 1. High affinity for oxygen
2. Stores oxygen in muscle and releases it when oxygen levels get low
3. Not affected by change in pH
4. 1 protein, 1 iron/heme, 1 oxygen
5. Tertiary structure
How does pH influence the oxygen saturation of hemoglobin?
ANSWER- Left shift: increased affinity for oxygen, increased pH (acidic), weak bond
Right shift: decreased affinity for oxygen, decreased pH, strong bond
Bohr Effect: increase in pH->increased affinity for oxygen->increased Hgb saturation-
>reach 100% sooner. Oxygen will be distributed better, delivering more or less where
,we need it.
Cholesterol
ANSWER- 1. 4 Ring structure
2. AKA sterols (cholesterol, cortisol, testosterone)
3. Needed for membrane fluidity (expansion)
4. Increases temp to solidify
5. Needed to synthesize Vitamin D in the skin, cholic acid (component of bile), and
steroid hormones.
Steroid Hormones
ANSWER- synthesized by cholesterol;
testosterone and estrogen-promote growth and development of sex characteristics;
cortisol-released in response to stress and promotes glucose synthesis in liver.
How could myoglobin indicate an MI?
ANSWER- Myoglobin is a protein with a single subunit containing both heme and
iron. While myoglobin is normally contained only in the muscles, it can be released into
the bloodstream if there is muscle damage. For this reason, measuring the levels of
myoglobin in the blood can provide evidence of rhabdomyolysis, a mild heart attack, or
a muscular degenerative disease.
Describe the Anabolic/Anaerobic Pathway.
ANSWER- Occurs when there is no oxygen. The ETC cannot work. Requires energy to
synthesize larger molecules.
NAD+ runs out->fermentation regenerates the NADH to NAD+ ->small amounts of ATP
and lactate are made->Cori Cycle in liver
*Ends in -GENESIS-*
Describe the Catabolic Pathway.
ANSWER- generates energy by breaking down larger molecules.
*Ends in -LYSIS-*
What do the Anabolic and Catabolic pathways have in common?
ANSWER- They are both required for maintaining the cell's energy balance.
Describe the Cori Cycle.
ANSWER- The Cori Cycle is part of the anabolic pathway. It uses the lactate
made by fermentation in the liver and uses gluconeogenesis to convert 2 lactate to
, glucose. 2 ATP are made with each cycle, but it uses 6. The net loss is -4 ATP.
Describe fermentation.
ANSWER- Fermentation is the formation of lactate by regenerating the NAD+ from
NADH that was used during glycolysis to make small amounts of ATP and lactate. It
allows glycolysis to continue in the absence of oxygen.
What does the Cori Cycle supply for red blood cells?
ANSWER- The Cori Cycle supplies glucose for RBCs.
The Cori Cycle takes up lactate from the blood and uses the gluconeogenesis pathway
to convert 2 molecules of lactate back to glucose. As the byproduct of anaerobic
glycolysis, lactate diffuses into the blood and is taken up by the liver where it is
converted back into pyruvate by the enzyme dehydrogenase. The newly formed
glucose is released into the blood to be used again for energy by the red blood cells
and muscles.
Because there is no oxygen present during the Cori Cycle, pyruvate from glycolysis is
converted to lactate. What happens to this lactate?
ANSWER- The lactate made from glycolysis is put into the blood. The liver picks up the
lactate and uses gluconeogenesis to convert 2 molecules of lactate into glucose.
Which molecule starts the citric acid cycle?
ANSWER- Acetyl-coA.
Describe the Citric Acid Cycle.
ANSWER- AKA Kreb's Cycle.
Takes in Acetyl CoA, NAD, FAD, and GDP.
Puts out CO2, NADH, FADH2, and GTP.
Takes place in mitrochondria.
A defect in this cycle will cause low levels of ATP.
It can be inhibited by increased levels of NADH d/t feedback inhibition.
What is needed in the Citric Acid Cycle to continue aerobic metabolism?
ANSWER- NADH and FADH2
What is the effect of glucagon on carbohydrate metabolism?
ANSWER- Converts glucose into glycogen for later use during hyopoglycemia.
Glycogenesis: the formation of glycogen from sugar.
If oxygen is scarce (anaerobic conditions, ie: exercise), what happens to pyruvate?
ANSWER- Pyruvate will be reduced via an anaerobic pathway by the addition of 2
