Cell Biology exam 1 Dr. Kim FIU - Exam review and
practice – Questions and Answers
For a motile eukaryotic cell, protrusion of the leading edge (lamellipodia) requires ____ .
a. F-Actin synthesis
b. Myosin II activation
c. Microtubule dynamic instability
d. Ubiquitin modification on Actin - -a. F-Actin synthesis
-In humans, there are about 200 different types of cells. Let's say that there are 50 trillion
cells in your body. On average, 50 billion cells die per day. If there were no stem cells,
our ..body would vanish in ____ days.
a. 10 days
b. 100 days
c. 1,000 days
d. 10,000 days - -c. 1,000 days
-Non-covalent bonds are critical in the regulation of cellular events. Which of the following
statement is correct?
a. Cells ensure constant pH by homeostasis mechanism and so ionic bonds between
macromolecules are always constitutive.
b. Water molecules form H-bonds with the carbonyl group of the polypeptide backbone
within the hydrophobic core of a stable globular protein.
c. Hydrophobic interaction is the only non-covalent interaction between alpha-helices of a
7-
TM receptor.
d. H-bonds exist in a single pass transmembrane alpha-helix. - -d. H-bonds exist in a single
pass transmembrane alpha-helix.
-Which of the following protein-protein interaction involves ionic bond?
a. Growth factor - RPTK
b. RPTK - Ras
c. Growth factor -Ras
d. Activated growth factor receptor - Grb2 - -d. Activated growth factor receptor - Grb2
-The side chain of amino acid Y is
(a) negatively charged
(b) able to form a disulfide bond
(c) positively charged
(d) able to be phosphorylated - -(d) able to be phosphorylated
-A peptide sequence is represented on a helix wheel diagram as shown here.
Which of the following statement is true?
a. It could be a transmembrane region of a 7-TM receptor
, b. It could be a transmembrane region of a membrane pore
c. It could be a transmembrane region of a single pass membrane protein
d. None of the above - -d. None of the above
-Which of the following protein utilize a lipid as its substrate?
a. PKA
b. Akt
c. RPTK
d. PI3K - -d. PI3K
-The small GTPase Ras will be activated upon binding GTP. Which of the following is the
physiological mechanism that cells utilize to activate Ras?
a. Directly add phosphate on GDP and thus convert it to GTP
b. Digest GDP to carbon dioxide
c. Destabilize GDP-Ras interactions and thus Ras will release GDP
d. Convert GDP to cGMP and thus Ras will be transiently free of nucleotide - -c. Destabilize
GDP-Ras interactions and thus Ras will release GDP
-If a lipase breaks a phospholipid at the bond between the glycerol backbone and the fatty
acid (ester bond), the shape of the glycerol backbone containing product would be ____.
a. a cylinder
b. a Cone
c. a Cube
d. an Icosahedron - -b. a Cone
-A corona virus escapes from an endosome by using which of the following mechanism?
a. activating Phospholipase
b. activating PKC
c. inducing membrane fusion
d. entering into a lysosome - -c. inducing membrane fusion
-Which if the following statement is true?
a. IP3 is a substrate of PI3K
b. PLC converts PIP3 into PI(4,5)P2
c. PTEN converts PI(4,5)P2 into IP3 and DAG
d. PLC can block PIP3 generation by depleting PI(4,5)P2 - -d. PLC can block PIP3
generation by depleting PI(4,5)P2
-When the the pH=6.9, the ratio of [Histidine/Histidine+] is?
a. 8.5
b.2.5
c.1.5
d.0.1 - -pH=pK + log(His/His+)
6.9 =6.5+log(His/His+)
0.4=log(His/His+) His/His+=2.5
practice – Questions and Answers
For a motile eukaryotic cell, protrusion of the leading edge (lamellipodia) requires ____ .
a. F-Actin synthesis
b. Myosin II activation
c. Microtubule dynamic instability
d. Ubiquitin modification on Actin - -a. F-Actin synthesis
-In humans, there are about 200 different types of cells. Let's say that there are 50 trillion
cells in your body. On average, 50 billion cells die per day. If there were no stem cells,
our ..body would vanish in ____ days.
a. 10 days
b. 100 days
c. 1,000 days
d. 10,000 days - -c. 1,000 days
-Non-covalent bonds are critical in the regulation of cellular events. Which of the following
statement is correct?
a. Cells ensure constant pH by homeostasis mechanism and so ionic bonds between
macromolecules are always constitutive.
b. Water molecules form H-bonds with the carbonyl group of the polypeptide backbone
within the hydrophobic core of a stable globular protein.
c. Hydrophobic interaction is the only non-covalent interaction between alpha-helices of a
7-
TM receptor.
d. H-bonds exist in a single pass transmembrane alpha-helix. - -d. H-bonds exist in a single
pass transmembrane alpha-helix.
-Which of the following protein-protein interaction involves ionic bond?
a. Growth factor - RPTK
b. RPTK - Ras
c. Growth factor -Ras
d. Activated growth factor receptor - Grb2 - -d. Activated growth factor receptor - Grb2
-The side chain of amino acid Y is
(a) negatively charged
(b) able to form a disulfide bond
(c) positively charged
(d) able to be phosphorylated - -(d) able to be phosphorylated
-A peptide sequence is represented on a helix wheel diagram as shown here.
Which of the following statement is true?
a. It could be a transmembrane region of a 7-TM receptor
, b. It could be a transmembrane region of a membrane pore
c. It could be a transmembrane region of a single pass membrane protein
d. None of the above - -d. None of the above
-Which of the following protein utilize a lipid as its substrate?
a. PKA
b. Akt
c. RPTK
d. PI3K - -d. PI3K
-The small GTPase Ras will be activated upon binding GTP. Which of the following is the
physiological mechanism that cells utilize to activate Ras?
a. Directly add phosphate on GDP and thus convert it to GTP
b. Digest GDP to carbon dioxide
c. Destabilize GDP-Ras interactions and thus Ras will release GDP
d. Convert GDP to cGMP and thus Ras will be transiently free of nucleotide - -c. Destabilize
GDP-Ras interactions and thus Ras will release GDP
-If a lipase breaks a phospholipid at the bond between the glycerol backbone and the fatty
acid (ester bond), the shape of the glycerol backbone containing product would be ____.
a. a cylinder
b. a Cone
c. a Cube
d. an Icosahedron - -b. a Cone
-A corona virus escapes from an endosome by using which of the following mechanism?
a. activating Phospholipase
b. activating PKC
c. inducing membrane fusion
d. entering into a lysosome - -c. inducing membrane fusion
-Which if the following statement is true?
a. IP3 is a substrate of PI3K
b. PLC converts PIP3 into PI(4,5)P2
c. PTEN converts PI(4,5)P2 into IP3 and DAG
d. PLC can block PIP3 generation by depleting PI(4,5)P2 - -d. PLC can block PIP3
generation by depleting PI(4,5)P2
-When the the pH=6.9, the ratio of [Histidine/Histidine+] is?
a. 8.5
b.2.5
c.1.5
d.0.1 - -pH=pK + log(His/His+)
6.9 =6.5+log(His/His+)
0.4=log(His/His+) His/His+=2.5
