I have seen so many good biochemistry and physiology questions being posted in the "Anatomy Questions" thread. Let's post the Biochem and Physiology questions in this thread to have them organized for future reference.
NBDE1 Biochem and Physiology Questions Only...
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The malate-aspartate shuttle .....
a) has one membrane carrier
b) transfers the electrons of cytoplasmic NADH to mitochondria at a cost of one ATP molecule
c) has a similar role to glycerol 3-phosphate shuttle
d) transfers alpha-ketoglutarate and aspartate across the inner-mitochondrial membrane via an antiport.
a) has one membrane carrier
b) transfers the electrons of cytoplasmic NADH to mitochondria at a cost of one ATP molecule
c) has a similar role to glycerol 3-phosphate shuttle
d) transfers alpha-ketoglutarate and aspartate across the inner-mitochondrial membrane via an antiport.
The malate-aspartate shuttle (sometimes also the malate shuttle) is a biochemical system for translocating electrons produced during glycolysis across the impermeable inner membrane of the mitochondrion for oxidative phosphorylation in eukaryotes. This allows the hydrogen ions (reduction equivalents) of the cofactor NADH produced in the cytosol to reach the electron transport chain in the mitochondria and generate ATP.
The glycerol-3-phosphate shuttle is a mechanism that regenerates NAD+ from NADH, a by-product of glycolysis. Its importance in transporting reducing equivalents is secondary to the malate-aspartate shuttle.
Both B-hydroxybutyric acid and acetoacetate are used by the brain, when there isn't enough glucose. In the liver, some of the acetoacetate is converted to B-hydroxybutyric acid, and some to acetone. Brain can convert acetoacetate and B-hydroxy butyric acid back to acetyl CoA for further use in the Citric cycle. Acetone cannot be converted to acetyl CoA though.
*B-hydroxybutyrate is just the reduced form of acetoacetate, and both can convert to each other reversibly by NADH/NAD+.
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plz explain
which of following best describe cell membranes
a.one layer of charged (polar) lipids
b.one layer of protein on the inside & one layer of neutral lipids on the outside
c.one layer of protein on either side of a layer of neutral lipids
d.one layer of charged (polar) lipids on either side of a layer of neutral lipids
Thanks
which of following best describe cell membranes
a.one layer of charged (polar) lipids
b.one layer of protein on the inside & one layer of neutral lipids on the outside
c.one layer of protein on either side of a layer of neutral lipids
d.one layer of charged (polar) lipids on either side of a layer of neutral lipids
Thanks
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An individual with XY sex chromosomes inherits a mutation that results in completely nonfunctional androgen receptors. Which one of the following would be true?
a. The person is genetically female.
b. The person will have functional ovaries.
c. In embryonic life, both the Wolffian ducts and the Müllerian ducts will fail to develop
d. The person will have the external appearance of a male.
Which one of the following drugs would likely help a patient suffering from hypertension?
a. A drug that stimulates alpha-receptors in cardiac muscle.
b. A drug that blocks muscarinic receptors in cardiac muscle.
c. A drug that blocks beta-receptors in cardiac muscle.
d. A drug that blocks receptors for atrial natriuretic peptide.
Which statement is NOT true?
a. Dendritic cell plasma membranes contain MHC molecules of both class I and class II.
b. Plasma membrane receptors on T-lymphocytes are heterodimers of alpha and beta chains.
c. Recently activated T-lymphocytes have higher levels of FAS receptors in their plasma membranes than T-lymphocytes that have been active for a longer period of time.
d. CD4-positive cells bind to antigens presented by class II MHC proteins.
a. The person is genetically female.
b. The person will have functional ovaries.
c. In embryonic life, both the Wolffian ducts and the Müllerian ducts will fail to develop
d. The person will have the external appearance of a male.
Which one of the following drugs would likely help a patient suffering from hypertension?
a. A drug that stimulates alpha-receptors in cardiac muscle.
b. A drug that blocks muscarinic receptors in cardiac muscle.
c. A drug that blocks beta-receptors in cardiac muscle.
d. A drug that blocks receptors for atrial natriuretic peptide.
Which statement is NOT true?
a. Dendritic cell plasma membranes contain MHC molecules of both class I and class II.
b. Plasma membrane receptors on T-lymphocytes are heterodimers of alpha and beta chains.
c. Recently activated T-lymphocytes have higher levels of FAS receptors in their plasma membranes than T-lymphocytes that have been active for a longer period of time.
d. CD4-positive cells bind to antigens presented by class II MHC proteins.
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All nucleated cells have MHC class I, except sperm cells (note than this also leaves RBC out, since they are not nucleated). Since dendritic cells are nucleated, they have Class I besides Class II. Choice (a) is a true statement ---> not the correct answer to this question.
Yo yo, I got new questions fo yo guys in my 100th post!
Which one of the following proteins in the membrane of the intestinal epithelial cell is most directly involved in the success of oral rehydration therapy as it is currently practiced in cases of bacterial gastroenteritis involving severe diarrhea?
a. Na+/K+ ATPase
b. CFTR Cl- channel
c. Na+-glucose symport
d. aquaporin
e. epithelial Na+ channel
A particular hormone is known to cause 5 different effects on its target cell, all mediated by the cyclic AMP system. A drug is discovered that blocks one of these effects, but not the other four effects. Which one of the following statements is most likely true?
a. The drug blocks adenylyl cyclase.
b. The drug blocks the Gs protein.
c. The drug binds to and inactivates cyclic AMP.
d. The drug blocks a protein phosphorylated by kinase A.
e. The drug blocks the hormone's receptors.
Which one of the following general statements about the structure of ion channels is false?
a. Cation-selective channels have transmembrane pores that contain a preponderance of negative charges.
b. Phosphorylation sites that regulate ion channel function are located on the cytoplasmic side of the protein.
c. The voltage-gated Na+ channel consists of 3 protein subunits.
d. Voltage-gated K+ channels are phylogenetically younger than voltage-gated Na+ channels
e. Portions of the transmembrane alpha helices that face the hydrocarbon-rich interior of the membrane are composed of non-polar amino acids.
Imagine a ligand-gated ion channel in the membrane of a typical resting neuron. The pore of this channel is equally permeable to Na+ and K+ ions. If the channel were briefly opened, which one of the following would occur?
a. Local currents on the outside of the membrane would flow away from that region.
b. Local currents on the inside of the membrane would flow away from that region.
c. A brief, local hyperpolarization of the membrane would occur.
d. Because the currents carried by Na+ and K+ would be equal and opposite, no local currents would flow.
Ok, enough😀
Which one of the following proteins in the membrane of the intestinal epithelial cell is most directly involved in the success of oral rehydration therapy as it is currently practiced in cases of bacterial gastroenteritis involving severe diarrhea?
a. Na+/K+ ATPase
b. CFTR Cl- channel
c. Na+-glucose symport
d. aquaporin
e. epithelial Na+ channel
A particular hormone is known to cause 5 different effects on its target cell, all mediated by the cyclic AMP system. A drug is discovered that blocks one of these effects, but not the other four effects. Which one of the following statements is most likely true?
a. The drug blocks adenylyl cyclase.
b. The drug blocks the Gs protein.
c. The drug binds to and inactivates cyclic AMP.
d. The drug blocks a protein phosphorylated by kinase A.
e. The drug blocks the hormone's receptors.
Which one of the following general statements about the structure of ion channels is false?
a. Cation-selective channels have transmembrane pores that contain a preponderance of negative charges.
b. Phosphorylation sites that regulate ion channel function are located on the cytoplasmic side of the protein.
c. The voltage-gated Na+ channel consists of 3 protein subunits.
d. Voltage-gated K+ channels are phylogenetically younger than voltage-gated Na+ channels
e. Portions of the transmembrane alpha helices that face the hydrocarbon-rich interior of the membrane are composed of non-polar amino acids.
Imagine a ligand-gated ion channel in the membrane of a typical resting neuron. The pore of this channel is equally permeable to Na+ and K+ ions. If the channel were briefly opened, which one of the following would occur?
a. Local currents on the outside of the membrane would flow away from that region.
b. Local currents on the inside of the membrane would flow away from that region.
c. A brief, local hyperpolarization of the membrane would occur.
d. Because the currents carried by Na+ and K+ would be equal and opposite, no local currents would flow.
Ok, enough😀
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Hi
Which statement is NOT true?
a. Dendritic cell plasma membranes contain MHC molecules of both class I and class II.
b. Plasma membrane receptors on T-lymphocytes are heterodimers of alpha and beta chains.
c. Recently activated T-lymphocytes have higher levels of FAS receptors in their plasma membranes than T-lymphocytes that have been active for a longer period of time. (ans)
d. CD4-positive cells bind to antigens presented by class II MHC proteins.[/QUOTE]
mature Tcells donot hv both CD4 & CD8 molecules on the same cell
Thanks
plz correct me if i m wrong
Which statement is NOT true?
a. Dendritic cell plasma membranes contain MHC molecules of both class I and class II.
b. Plasma membrane receptors on T-lymphocytes are heterodimers of alpha and beta chains.
c. Recently activated T-lymphocytes have higher levels of FAS receptors in their plasma membranes than T-lymphocytes that have been active for a longer period of time. (ans)
d. CD4-positive cells bind to antigens presented by class II MHC proteins.[/QUOTE]
mature Tcells donot hv both CD4 & CD8 molecules on the same cell
Thanks
plz correct me if i m wrong
I didn't understand the reasoning behind your answer, but (C) is the false statement and therefore, the correct answer. The older a lymphocyte gets, it expresses more FAS receptors, which leads in its inactivation by apoptosis. The binding of FASL (FAS ligand) to FAS receptors, which leads to the apoptosis of the lymphocytes, is a mechanism used to reduce the immune response once its action has been carried out. Older T lymphocytes (which have most probably carried out their action) express more FAS receptors.
Which category of enzymes is essential for breaking down the aromatic ring of aminoacids ?
1)carboxylase
2)dehydrogenase
3)dioxygenase
4)decarboxylase
Which cycle is more efficient? Cori cycle or Alanine cycle? Explain......
Name the two aminoacids that are ONLY ketogenic.
1)carboxylase
2)dehydrogenase
3)dioxygenase
4)decarboxylase
Which cycle is more efficient? Cori cycle or Alanine cycle? Explain......
Name the two aminoacids that are ONLY ketogenic.
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2)Alanine cycle is is more efficient energetically
www.ches.ua.edu/departments/nhm/faculty/neggers/nhm562/gluconeo-IV.pdf
3)Leucine and lysine are only ketogenic AA
www.ches.ua.edu/departments/nhm/faculty/neggers/nhm562/gluconeo-IV.pdf
3)Leucine and lysine are only ketogenic AA
Which one of the following proteins in the membrane of the intestinal epithelial cell is most directly involved in the success of oral rehydration therapy as it is currently practiced in cases of bacterial gastroenteritis involving severe diarrhea?
a. Na+/K+ ATPase
b. CFTR Cl- channel
c. Na+-glucose symport{answer}
d. aquaporin
e. epithelial Na+ channel
plz correct if wrong
a. Na+/K+ ATPase
b. CFTR Cl- channel
c. Na+-glucose symport{answer}
d. aquaporin
e. epithelial Na+ channel
plz correct if wrong
A particular hormone is known to cause 5 different effects on its target cell, all mediated by the cyclic AMP system. A drug is discovered that blocks one of these effects, but not the other four effects. Which one of the following statements is most likely true?
a. The drug blocks adenylyl cyclase.
b. The drug blocks the Gs protein.
c. The drug binds to and inactivates cyclic AMP.
d. The drug blocks a protein phosphorylated by kinase A.{answer}
e. The drug blocks the hormone's receptors.
a. The drug blocks adenylyl cyclase.
b. The drug blocks the Gs protein.
c. The drug binds to and inactivates cyclic AMP.
d. The drug blocks a protein phosphorylated by kinase A.{answer}
e. The drug blocks the hormone's receptors.
Oops, I just noticed I had screwed up spelling Dioxygenase (correct spelling) wrongly in my original post. Dioxygenases use O2 to break the aromatic ring of F, Y, and W by the help of their Fe cofactor, which is not part of any heme or iron-sulfur cluster.
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CO2 (The one carbon unit at the highest oxidation state) is carried by biotin, the cofactor of almost all carboxylases in the cell. The other one carbon units are carried by tetrahydrofolate.
In which of the following conditions is oxygen partial pressure low in arterial blood?
1-anemia
2-polycythemia
3-pulmonary av shunt
4-hypovolemia due to hemorrahge
what are the best describe gtp binding proteins g protein?
How to calculate the net charge on glutamic acid at ph 1?
Each of following occure during long starvation except?
1-circulation of t4 is converted t3(reverse t3)
2-ketoacidosis develop progressivly
3-insulin level are depressed
4-primary fuel is glycogen
slight detachment of retina result in decrease of length from the optical center and the subject therefore exhibit
1-near sightdness
2-far sightedness
3-strabismus
4-nystagmus
how to calculate the concentration of flourid in ppm?
Urine sample with ph of 5.7 has hydrogen ion concentration approximatly?
Expain please
1-anemia
2-polycythemia
3-pulmonary av shunt
4-hypovolemia due to hemorrahge
what are the best describe gtp binding proteins g protein?
How to calculate the net charge on glutamic acid at ph 1?
Each of following occure during long starvation except?
1-circulation of t4 is converted t3(reverse t3)
2-ketoacidosis develop progressivly
3-insulin level are depressed
4-primary fuel is glycogen
slight detachment of retina result in decrease of length from the optical center and the subject therefore exhibit
1-near sightdness
2-far sightedness
3-strabismus
4-nystagmus
how to calculate the concentration of flourid in ppm?
Urine sample with ph of 5.7 has hydrogen ion concentration approximatly?
Expain please
thank you for fast reply
MOUTH RINSE CONTAINS 0.05 PERCENT FLOURIDE WHICH OF THE FOLLOWING REPRESENTS THE CONCENTRATIONS EXPRESSED AS PPM FLOURIDE?
1-5
2-50
3-500
4-5000
Urine sample with ph of 5.7 has hydrogen ion concentration approximatly?
2*10^-3
2*10^-6
1*10^-3
THE CORRECT ANS IS 2*10^-6
I WANT TO KNOW WHY IT IS 2
THANKS AGAIN
MOUTH RINSE CONTAINS 0.05 PERCENT FLOURIDE WHICH OF THE FOLLOWING REPRESENTS THE CONCENTRATIONS EXPRESSED AS PPM FLOURIDE?
1-5
2-50
3-500
4-5000
Urine sample with ph of 5.7 has hydrogen ion concentration approximatly?
2*10^-3
2*10^-6
1*10^-3
THE CORRECT ANS IS 2*10^-6
I WANT TO KNOW WHY IT IS 2
THANKS AGAIN
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Each of the following can be increased by the polypeptide harmone, except one,which one is the exception
a]inositol triphosphate conc
b]intracellular ca conc
c]intracelluar phosphate conc
d]adenylate cyclase activity
e]protein kinase c activity
If some one can please explain the ans also
a]inositol triphosphate conc
b]intracellular ca conc
c]intracelluar phosphate conc
d]adenylate cyclase activity
e]protein kinase c activity
If some one can please explain the ans also
Each of the following can be increased by the polypeptide harmone, except one,which one is the exception
a]inositol triphosphate conc
b]intracellular ca conc
c]intracelluar phosphate conc(answer}
d]adenylate cyclase activity
e]protein kinase c activity
If some one can please explain the ans also
i think this is th answer coz choices{a,d,e} r examples of secondary messenger ,all water soluble hormones{ie peptides n biogenic amines }stimulate th production of seconday messengers .choices {b,c} r related to parathyroid hormone which is a peptide ,so it will decrese th level of phosphate.
plz correct if wrong
a]inositol triphosphate conc
b]intracellular ca conc
c]intracelluar phosphate conc(answer}
d]adenylate cyclase activity
e]protein kinase c activity
If some one can please explain the ans also
i think this is th answer coz choices{a,d,e} r examples of secondary messenger ,all water soluble hormones{ie peptides n biogenic amines }stimulate th production of seconday messengers .choices {b,c} r related to parathyroid hormone which is a peptide ,so it will decrese th level of phosphate.
plz correct if wrong
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Thanks
which of the following vitamin derivative is needed for converting glucose to lactic acid.
a]Thiamine
b]paniothenic acid
c]pyridoxine
d]Nicotinamide
e]cholecalciferol
Recognition of ACTH by its target cell depends upon the binding of the harmone to its specific receptor on the
a]mitochondrial matrix
b]nuclear memb
c]cell memb
d]lysosomal memb
e]chromosome
plz explain your ans
which of the following vitamin derivative is needed for converting glucose to lactic acid.
a]Thiamine
b]paniothenic acid
c]pyridoxine
d]Nicotinamide
e]cholecalciferol
Recognition of ACTH by its target cell depends upon the binding of the harmone to its specific receptor on the
a]mitochondrial matrix
b]nuclear memb
c]cell memb
d]lysosomal memb
e]chromosome
plz explain your ans
which of the following vitamin derivative is needed for converting glucose to lactic acid.
a]Thiamine
b]paniothenic acid
c]pyridoxine
d]Nicotinamide
e]cholecalciferol
not sure abt th answer ,may be a or d
Recognition of ACTH by its target cell depends upon the binding of the harmone to its specific receptor on the
a]mitochondrial matrix
b]nuclear memb{answer}
c]cell memb
d]lysosomal memb
e]chromosome
a]Thiamine
b]paniothenic acid
c]pyridoxine
d]Nicotinamide
e]cholecalciferol
not sure abt th answer ,may be a or d
Recognition of ACTH by its target cell depends upon the binding of the harmone to its specific receptor on the
a]mitochondrial matrix
b]nuclear memb{answer}
c]cell memb
d]lysosomal memb
e]chromosome
Recognition of ACTH by its target cell depends upon the binding of the harmone to its specific receptor on the
a]mitochondrial matrix
b]nuclear membrane
c]cell memb
d]lysosomal memb
e]chromosome ....ans
sorry ,choice e should be th answer coz lipid soluble hormones{ie steroids n thyroid hormones}cross th plasma and nuclear membranes of their target cells readily and attach to receptors on the nuclear chromatin.
a]mitochondrial matrix
b]nuclear membrane
c]cell memb
d]lysosomal memb
e]chromosome ....ans
sorry ,choice e should be th answer coz lipid soluble hormones{ie steroids n thyroid hormones}cross th plasma and nuclear membranes of their target cells readily and attach to receptors on the nuclear chromatin.
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i thought lipid soluble hormones attatch on nuclear membrane?
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"ACTH acts through the stimulation of cell surface ACTH receptors, which are primarily located on adrenocortical cells of the adrenal cortex. This results in the synthesis and secretion of gluco- and mineralo-corticosteroids, and androgenic steroids. The ACTH receptor is a seven membrane-spanning G-protein coupled receptor. Upon ligand binding, the receptor undergoes conformation changes that stimulate the enzyme adenylyl cyclase, which leads to an increase in intracellular cAMP and subsequent activation of protein kinase A. This ultimately results in stimulation of steroidogenesis."
so answer should be cell membrane
so answer should be cell membrane
