BIOD 101 EXAM 5 PREP QUESTIONS WITH
CORRECT ANSWERS
What type of signaling occurs during periods of development, specifically in the secretion of Gro
wth Factors? - CORRECT ANSWER -Paracrine Signaling-
always related to Growth factors (cell releases vesicles containing signal ligands)
What type of signaling is common to immune cells and to the progression and metastasis (sprea
ding) of cancer cells? - CORRECT ANSWER -Autocrine Signaling-
a cell acts as both the sender and receiver of a signal. Auto/Apoptosis. IMMUNE
What type of signaling occurs over a long distance, such as when the circulatory system serves a
s the transport medium to move endocrine ligands around the body? - CORRECT ANSWER -
Endocrine signaling-
HOMEOSTATIC/Hormones. Used to transmit ligands to their target cells over long distances.
What type of signaling occurs in the heart and muscle cells, intracellularly? -
CORRECT ANSWER -Direct cell-to-
cell signaling: involves contact between the sending cell and the target cell. (Gap junctions allow
small molecules (such as calcium) to flow easily from cells connected to one another. This flow
allows for a coordinated response by groups of connected cells.
Explain why a steroid hormone would require a carrier protein to transport it through the blood
stream? - CORRECT ANSWER -
Steroid hormones are hydrophobic (avoid water). They would require a carrier protein (hydrophi
lic) to carry it through the bloodstream.
When a signaling ligand binds to the extracellular binding region of an RTK, what happens THIR
D? - CORRECT ANSWER -3= Inactive relay proteins become activated.
RTK steps:
1) dimerization of individual monomers
, 2) Auto-phosphorylation
3) Inactive relay proteins become activated.
Each of the following is TRUE EXCEPT what regarding cellular receptors?
1) Receptors in each family are classified by structural and functional similarities.
2) Most receptors are located on the outside of a cell, anchored into the plasma membrane
3) They are located in the cell's cytoplasm or in the nucleus - CORRECT ANSWER -
#3 False= true is= on cell's plasma membrane
What is a ligand? What isBits role in cellular signaling? - CORRECT ANSWER -
A ligand is a molecule that has specificity for a given receptor, and the binding of a ligand to the
given receptor causes a change.
Fill in the blank:
is the chain of molecules and intracellular enzymes that relay signals inside of a cell. Most
often (But not always), the molecules that act in the relay chain are .-
CORRECT ANSWER -Transduction; proteins.
What of the following is true of GPCRs?
1) They thread through the plasma membrane forming loops.
2) they are transmembrane hormone receptors
3) a modified loop receives ligands on the intracellular side - CORRECT ANSWER -
Just #1. They thread through the plasma membrane forming loops.
-more than just hormones,
- no modified
T/F. For most biological processes, a typical response would be the release of millions of molecu
les for every ligand. - CORRECT ANSWER -TRUE.
CORRECT ANSWERS
What type of signaling occurs during periods of development, specifically in the secretion of Gro
wth Factors? - CORRECT ANSWER -Paracrine Signaling-
always related to Growth factors (cell releases vesicles containing signal ligands)
What type of signaling is common to immune cells and to the progression and metastasis (sprea
ding) of cancer cells? - CORRECT ANSWER -Autocrine Signaling-
a cell acts as both the sender and receiver of a signal. Auto/Apoptosis. IMMUNE
What type of signaling occurs over a long distance, such as when the circulatory system serves a
s the transport medium to move endocrine ligands around the body? - CORRECT ANSWER -
Endocrine signaling-
HOMEOSTATIC/Hormones. Used to transmit ligands to their target cells over long distances.
What type of signaling occurs in the heart and muscle cells, intracellularly? -
CORRECT ANSWER -Direct cell-to-
cell signaling: involves contact between the sending cell and the target cell. (Gap junctions allow
small molecules (such as calcium) to flow easily from cells connected to one another. This flow
allows for a coordinated response by groups of connected cells.
Explain why a steroid hormone would require a carrier protein to transport it through the blood
stream? - CORRECT ANSWER -
Steroid hormones are hydrophobic (avoid water). They would require a carrier protein (hydrophi
lic) to carry it through the bloodstream.
When a signaling ligand binds to the extracellular binding region of an RTK, what happens THIR
D? - CORRECT ANSWER -3= Inactive relay proteins become activated.
RTK steps:
1) dimerization of individual monomers
, 2) Auto-phosphorylation
3) Inactive relay proteins become activated.
Each of the following is TRUE EXCEPT what regarding cellular receptors?
1) Receptors in each family are classified by structural and functional similarities.
2) Most receptors are located on the outside of a cell, anchored into the plasma membrane
3) They are located in the cell's cytoplasm or in the nucleus - CORRECT ANSWER -
#3 False= true is= on cell's plasma membrane
What is a ligand? What isBits role in cellular signaling? - CORRECT ANSWER -
A ligand is a molecule that has specificity for a given receptor, and the binding of a ligand to the
given receptor causes a change.
Fill in the blank:
is the chain of molecules and intracellular enzymes that relay signals inside of a cell. Most
often (But not always), the molecules that act in the relay chain are .-
CORRECT ANSWER -Transduction; proteins.
What of the following is true of GPCRs?
1) They thread through the plasma membrane forming loops.
2) they are transmembrane hormone receptors
3) a modified loop receives ligands on the intracellular side - CORRECT ANSWER -
Just #1. They thread through the plasma membrane forming loops.
-more than just hormones,
- no modified
T/F. For most biological processes, a typical response would be the release of millions of molecu
les for every ligand. - CORRECT ANSWER -TRUE.
