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WorksheetsYr 12 Biology - Signal Transduction & Apoptosis
Total questions: 40
Worksheet time: 31mins
I. Response
II. Amplification
III. Reception
IV. Transduction
Which of the following represents the sequence of events in a typical signal transduction pathway?
Identify the secondary messenger.
Which of the following best describes the role in which the G protein is most intimately involved in the process shown above?
Neurons release acetylcholine (ACh) into the gap between the nerve cell and a muscle cell. ACh then binds to receptors in the muscle cell membrane, resulting in the release of Ca2+ from the smooth ER
autocrine signalling
juxtacrine signalling
paracrine signalling
endocrine signalling
type of cell signalling where the ligand is released and will affect cells in its "neighborhood"
autocrine signalling
juxtacrine signalling
paracrine signalling
endocrine signalling
Glucagon, released from the pancreas, attaches to receptors in the liver, resulting in the breakdown of glycogen stores and an increase in blood sugar
autocrine signalling
juxtacrine signalling
paracrine signalling
endocrine signalling
type of cell signalling where the ligand is produced at a location distant from its target cell(s)
autocrine signalling
juxtacrine signalling
paracrine signalling
endocrine signalling
What is being depicted in the image?
Amplification of the signal molecule
Enzymatic proteins inhibiting process of the signal transduction pathway
Kinase groups adding dimer groups to other enzymes
Diffusion of molecules within the cell due to the signaling molecule
There are four basic types of cell signaling, EXCEPT
paracrine
autocrine
direct contact
endocrine
exocrine
What are the three types of signals that cells can receive? Mark all that apply
Hormones
Neurotransmitters
ATP
Extracellular chemicals (Environment)
Signals can exert their effects locally or travel long distances
true
false
In the signal transduction mechanism known as protein phosphorylation
the signaling molecule binds to a surface receptor
receptor kinases play a key role in triggering the signal cascade
phosphorylated proteins act with enzymes to trigger the signal cascade
All of the above
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
Phosphorylation __________.
always inactivates a protein
activates G-protein-linked receptors
can either activate or inactivate a protein
is accomplished by protein phosphatases
always activates a protein
The cellular response of a signal pathway that terminates at a transcription factor would be __________.
the synthesis of mRNA
the activation of an inactive enzyme
alteration of the cytoskeleton
a change in the chemical composition of the cytosolic environment
the activation of a metabolic pathway
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
The source of phosphate for a phosphorylation cascade is __________.
cAMP
protein kinase
GTP
ATP
protein phosphatase
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
Cell signaling can be classified into
distinct types based on the distance over which the signaling molecules act
two distinct types based on the distance over which the signaling molecules act
distinct types based on the signaling molecules
none of the above
What is Apoptosis?
Cell programmed Death
Inflammation of cell
Phagocytosis
Plasmolysis
Give the correct sequence of apoptosis:
1. Nucleus begins to break
2. Nucleus condensation and formation of bleb
3. Phagocytosis of apoptotic bodies.
1, 2, 3
2, 3, 1
3, 2, 1
2,1,3
What could be the cause for a cell to undergo apoptosis?
DNA Damage
Nutrient deficiency
Radiation
All of the above
Which is correct? (2)
Necrosis is uncontrolled cell death
Necrosis is programmed cell death
Apoptosis is uncontrolled cell death
Apoptosis is programmed cell death
Why is apoptosis required?
Glycolysis
Cell division: Meiosis and mitosis
Growth and elimination of threats such as viruses and DNA damage
When a cell undergoes apoptosis:
cytokines produced by phagocytes protect surrounding cells by reducing inflammation.
it swells until it bursts.
it is as a result of being seriously damaged by chemical or mechanical trauma.
its mitochondria are destroyed along with all other organelles.
Which is the best representation of the stimulus-response pathway?
receptor → stimulus → control centre → response → effector
stimulus → receptor → control centre → effector → response
control centre → stimulus → receptor → effector → response
effector → control centre → receptor → stimulus → response
Feedback mechanisms are important in the homeostatic control of the body’s internal conditions. In a feedback system of control which of the following is true?
The stimulus alters the original effect of the stimulus.
the response alters the original effect of the stimulus.
the response reduces the effect of the original stimulus.
the response increases the effect of the original stimulus.
