BIOD 101 MODULE 5 (EXAM)
Briefly describe the process of phosphorylation.
- answers-Phosphorylation is the reversible process of adding a phosphate to one or
more sites on a molecule to activate it (turn it "on") or inactivate it (turn it "off").
Each of the following is true regarding cellular receptors except:
1. Receptors in each family are classified by their location in the body.
2. Most receptors are located on the outside of a cell, anchored in the plasma
membrane.
3. Cell surface receptors contain an extracellular region, intracellular region, and a
hydrophobic region in the plasma membrane.
4. Intracellular receptors are located in the cell's cytoplasm.
- answers-Receptors in each family are classified by their location in the body.
Explain how a cellular signaling pathway is terminated.
- answers-Ligands binding to their receptors is a reversible phenomenon. As the
concentration of signaling ligands decreases, fewer molecules bind to the receptors to
initiate a transduction pathway and response. When the receptors are not being
activated, the cell returns to a resting, inactive state.
Explain how the activation of mitochondrial proteins induce apoptosis.
- answers-Upon activation of these proteins, a conformational change occurs, allowing
these proteins to form tiny, molecular pores. The resulting pores cause the
mitochondrial outer membrane to leak, which releases other pro-apoptotic proteins
which work to degrade and disassemble the inner contents of the cell.
Explain the relationship between cancer development and apoptosis.
- answers-Cells that undergo apoptosis typically have something wrong with them. This
process helps to maintain normal cell functioning and growth. When cells resist
apoptosis and continue to divide, cancer can often develop.
Explain why a steroid hormone would require a carrier protein to transport it through the
bloodstream.
- answers-Steroid hormones are hydrophobic. They would require a carrier protein to
carry it through the blood because it is considered hydrophilic.
, Fill in the Blank in the following paragraph describing the signaling pathway.
Signaling begins when an extracellular ___________ binds to a receptor anchored
within the plasma membrane. Relay molecules and scaffolding proteins ___________
the signal to activate a cellular response.
- answers-1. Ligands
2. Transduce
Fill in the Blank:
For most biological processes, a typical response would be the release of ___________
of molecules every ___________ that binds.
- answers-1. Millions
2. Ligand
Fill in the Blank:
G proteins share the broad function of ___________ GTP to GDP.
- answers-Hydrolyzing (breaking down).
Fill in the Blank:
Transduction is the chain of ___________ and intracellular ___________ that relay
signals inside of a cell.
- answers-1. Molecules
2. Enzymes
Ligand-gated ion channels are the main receptor type for what cells in the human body?
- answers-Neurons.
List TWO specific examples of cellular ligands.
- answers-Hormones, peptides, sugars, and other hydrophobic molecules.
So calcium and female sex hormones would classify as ligands.
Mach each of the following terms with the correct description.
1. Autocrine signaling
2. Endocrine signaling
3. Direct cell-to-cell signaling
4. Paracrine signaling
5. Synaptic signaling
Briefly describe the process of phosphorylation.
- answers-Phosphorylation is the reversible process of adding a phosphate to one or
more sites on a molecule to activate it (turn it "on") or inactivate it (turn it "off").
Each of the following is true regarding cellular receptors except:
1. Receptors in each family are classified by their location in the body.
2. Most receptors are located on the outside of a cell, anchored in the plasma
membrane.
3. Cell surface receptors contain an extracellular region, intracellular region, and a
hydrophobic region in the plasma membrane.
4. Intracellular receptors are located in the cell's cytoplasm.
- answers-Receptors in each family are classified by their location in the body.
Explain how a cellular signaling pathway is terminated.
- answers-Ligands binding to their receptors is a reversible phenomenon. As the
concentration of signaling ligands decreases, fewer molecules bind to the receptors to
initiate a transduction pathway and response. When the receptors are not being
activated, the cell returns to a resting, inactive state.
Explain how the activation of mitochondrial proteins induce apoptosis.
- answers-Upon activation of these proteins, a conformational change occurs, allowing
these proteins to form tiny, molecular pores. The resulting pores cause the
mitochondrial outer membrane to leak, which releases other pro-apoptotic proteins
which work to degrade and disassemble the inner contents of the cell.
Explain the relationship between cancer development and apoptosis.
- answers-Cells that undergo apoptosis typically have something wrong with them. This
process helps to maintain normal cell functioning and growth. When cells resist
apoptosis and continue to divide, cancer can often develop.
Explain why a steroid hormone would require a carrier protein to transport it through the
bloodstream.
- answers-Steroid hormones are hydrophobic. They would require a carrier protein to
carry it through the blood because it is considered hydrophilic.
, Fill in the Blank in the following paragraph describing the signaling pathway.
Signaling begins when an extracellular ___________ binds to a receptor anchored
within the plasma membrane. Relay molecules and scaffolding proteins ___________
the signal to activate a cellular response.
- answers-1. Ligands
2. Transduce
Fill in the Blank:
For most biological processes, a typical response would be the release of ___________
of molecules every ___________ that binds.
- answers-1. Millions
2. Ligand
Fill in the Blank:
G proteins share the broad function of ___________ GTP to GDP.
- answers-Hydrolyzing (breaking down).
Fill in the Blank:
Transduction is the chain of ___________ and intracellular ___________ that relay
signals inside of a cell.
- answers-1. Molecules
2. Enzymes
Ligand-gated ion channels are the main receptor type for what cells in the human body?
- answers-Neurons.
List TWO specific examples of cellular ligands.
- answers-Hormones, peptides, sugars, and other hydrophobic molecules.
So calcium and female sex hormones would classify as ligands.
Mach each of the following terms with the correct description.
1. Autocrine signaling
2. Endocrine signaling
3. Direct cell-to-cell signaling
4. Paracrine signaling
5. Synaptic signaling
