CELLULAR AND MOLECULAR BIOLOGYFINAL EXAM LATEST 2024 WITH UPDATED QUESTIONS AND DETAILED CORRECT ANSWERS WITH RATIONALES (ALREADY GRADED A+)

CELLULAR AND MOLECULAR
BIOLOGYFINAL EXAM LATEST 2024 WITH
UPDATED QUESTIONS AND DETAILED
CORRECT ANSWERS WITH RATIONALES
(ALREADY GRADED A+)
Many signal transduction pathways use second messengers to:
A. Transport a signal through the lipid bilayer portion of the
plasma membrane
B. relay a signal from the outside to the inside of the cell
C. relay the message from the inside of the membrane throughout
the cytoplasm
D. amplify the message by phosphorylating proteins - ANSWERrelay the message from the inside of the membrane throughout
the cytoplasm
What is a G protein?
A. A protein on the cytoplasmic side of the a membrane that
becomes activated by a receptor protein
B. A specific type of membrane receptor protein
C. A membrane bound enzyme that converts ATP to cAMP
D. A tyrosine kinase relay protein - ANSWER-A protein on the
cytoplasmic side of the a membrane that becomes activated by a
receptor protein
Signaled responses that involve changes in _______ occur
_______
A. gene expression, slowly
B. protein modification, slowly
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C. gene expression, quickly
D. cell proliferation, quickly - ANSWER-gene expression, slowly
Sort the following events to reflect to normal order in which they
occur in G-protein-coupled receptor signaling leading to
transcription of genes with cAMP response elements. Your
answer would be a four-letter string composed of letters A-E only,
e.g. ACBD.
A. DCBA
B. BDAC
C. CBDA
D. DBCA - ANSWER-DBCA
Which of the following statements is false
A. Cyclic AMP is generated following activation of the Gs subunit
of a G-protein
B. Four cyclic AMP molecules are produced by each adenylyl
cyclase molecule, which in turn activate one PKA molecule
C. Adenylyl cyclase serves to transduce and amplify the signal
from the G protein coupled receptor (GCPR)
D. The activated PKA molecule is rest to the inactive form of PKA
by phosphodiesterase activity
E. The catalytic subunits of PKA are released from the inactive
PKA molecule following cAMP binding to the regulatory subunit by
a conformational shape change in PKA - ANSWER-Four cyclic
AMP molecules are produced by each adenylyl cyclase molecule,
which in turn activate one PKA molecule
A cell expresses a transmembrane protein that is cleaved at the
plasma membrane to release an extracellular fragment. The
fragment binds to receptor proteins on nearby cells and activates
signaling pathways resulting in altered gene expression patterns
in the cells. What form of intercellular signaling does this
represent?
A. Contact-dependent signaling
B. Paracrine signaling
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C. Synaptic signaling
D. Endocrine signaling
E. Autocrine signaling - ANSWER-Paracrine signaling
What statement about Synaptic Signaling is NOT true?
A. Rapidly transmit signal over long distances
B. Acts locally at a precise location
C. Acts as low local concentrations
D. Signal can be rapidly terminated
E. All of the above are correct - ANSWER-Acts at low local
concentrations
What statement about endocrine signaling is NOT true?
A. Slowly transmit signal over long distances
B. Relies on diffusion and blood flow
C. Acts broadly over the entire organism
D. Acts at low concentrations
E. Signal can be rapidly terminated - ANSWER-Signal can be
rapidly terminated