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WorksheetsAP Biology Cell communication
Total questions: 25
Worksheet time: 17mins
An example of LOCAL cell communication is:
White blood cells bumping into each other sharing antigen info
Neurons communicating across a synapse
Hormones traveling through the blood stream to target tissues
An example of DIRECT cell communication is:
White blood cells bumping into each other sharing antigen info
Neurons communicating across a synapse
Hormones traveling through the blood stream to target tissues
The figure above shows a model of a ligand precursor being cleaved to produce an active ligand that binds to a specific receptor. Which of the following is most likely to reduce the binding of the active ligand to its receptor?
A change in the cytoskeletal attachment of transmembrane proteins
The presence of a large amount of the precursor form of the ligand
An increase in the ratio of the number of unsaturated to the number of saturated fatty acid tails of the membrane lipids
A mutation in the receptor gene that causes a substitution of a charged amino acid for a nonpolar amino acid in the ligand binding site of the receptor
The binding of a ligand to a ligand-gated ion channel can cause the channel to ___.
open
close
both answers can be correct
A cell converting a chemical signal into a cellular response is known as __.
energetics
transduction
ligand response
transformation
After a ligand binds, the intracellular domain of a receptor protein changes _____, initiating transduction of the signal.
color
size
shape
Which of the following is a chemical message that usually travels through the bloodstream to target cells?
hormone
local regulator
endocrine cell
plasmodesmata
Signal amplification is most often achieved by
an phosphorylation cascade
binding of multiple signals
branching pathways
action of adenylyl cyclase
What do secondary messengers, like cAMP, do?
transport a signal through the lipid bilayer
relay & amplify a signal from the outside to the inside of the cell
relay & amplify a message from the inside of the membrane throughout the cytoplasm
dampen the message
The general name for an enzyme that transfers phosphate groups from ATP to a protein is __________.
protein dehydrogenase
protein kinase
protein phosphatase
peptidase
protein cyclase
Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because __________.
they are species specific.
the number of molecules used is small and fixed.
they always lead to the same cellular response.
they amplify the original signal manyfold.
they counter the harmful effects of phosphatases.
Receptors for signal molecules __________.
all work via protein kinases
are never found in the nucleus of a cell
may be found embedded in the plasma membrane, or found within the cytoplasm or nucleus
all work by opening ion channels
are only found associated with the plasma membrane
What is an organic compound that is made by glands in the body (pituitary, thyroid, etc) that is used in long distance communication between cells?
Hormones
Neurotransmitters
Synapse
Carbohydrates
What type of transmembrane receptor is being shown?
gated ion channel
G-protein receptor
What event would activate a G protein?
replacement of GDP with GTP
hydrolysis of GTP to GDP
hydrolysis of GDP to GTP
phosphorylation of GDP to GTP
phosphorylation of GTP to GDP
Testosterone does not affect all cells of the body because __________.
testosterone cannot cross the plasma membrane
not all cells have cytoplasmic receptors for testosterone
not all cells in the body have membrane receptors for testosterone
it is a local regulator
it affects only cells that have ion-channel receptors
Second messengers tend to be water-soluble and small. This accounts for their ability to __________.
rapidly cross the plasma membrane
pass quickly from cell to cell
move from substrate to substrate during a phosphorylation cascade
rapidly move throughout the cell by diffusion
cross the nuclear membrane and interact with DNA
Lipid-soluble signaling molecules, such as testosterone, cross the membranes of all cells but affect only target cells because __________.
only target cells retain the appropriate DNA segments
most cells lack the Y chromosome required
only target cells possess the cytosolic enzymes that transduce the testosterone
only in target cells is testosterone able to initiate the phosphorylation cascade leading to activated transcription factor
intracellular receptors are present only in target cells
The source of phosphate for a phosphorylation cascade is __________.
cAMP
protein kinase
GTP
ATP
protein phosphatase
