BIOL 373 Exam
What is physiology? - correct answer ✔✔N The science of the function of living system
What is the difference between process and function? - correct answer ✔✔N - process = "how"
- function = "why"
What is homeostasis with respect to a fluid? - correct answer ✔✔N Maintenance of a relatively stable
internal cellular fluid
Who coined the term "homeostasis?" - correct answer ✔✔N Walter Cannon
What is pathophysiology? - correct answer ✔✔N The study of when systems fail to compensate
What is local control? Reflex control? What modulates reflex control? - correct answer ✔✔N - local
control = changes near the site of damage
- reflex control = over long distances; managed by the CNS
List some examples of variables monitored by the CNS - correct answer ✔✔N - osmolarity
-T
- BP
What are the three types of feedback mechanisms? Which is most common? least common? - correct
answer ✔✔N Negative, positive and feedforward. Negative feedback →negative very common
→positive very rare
What is responsible for most communication - electrical or chemical signals? - correct answer ✔✔N
Chemical
,Define target cells WRT sent signals. - correct answer ✔✔N Target cells are those cells which are able to
respond to chemical signals, and contain a receptor for it.
What are forms of long-range cell-cell communication? - correct answer ✔✔N endocrine (chemical
hormone), neural and neuro endocrine (chemicals at axon terminal secrete into the bloodstream).
Where are ligand receptors located? What do these specific locations yield in terms of function? - correct
answer ✔✔N A *protein* which projects outside of the membrane or are within the membrane;
hydrophobic ligands will diffuse into the cytoplasm; hydrophilic via an intracellular receptor (consider the
lipo and hydrophobicity WRT location)
name the three main types of membrane receptors covered in 373. - correct answer ✔✔N - ion channel
- enzyme-coupled receptor
- GPCR
What are the main types of second messengers? Name a representative member of each. - correct
answer ✔✔N - nucleotides; cAMP
- lipid-derived molecules; IP_3
- ions; Ca²⁺
How can one signal have different effects on different cell types? - correct answer ✔✔N One ligand may
have several different types of receptors
What aspects of kinetics and thermodynamics affect ligand-receptor interactions? - correct answer ✔✔N
K_eq (rel. affinity), saturation
How can cells change their response to signals? - correct answer ✔✔N - ↑ n_receptors by changing
receptor number or sensitivity
- ↓ n_receptors by internalizing the surface protein
*- Δsensitivity by ℗*
, What are the effects of Epi on α receptors? β₂ receptors? - correct answer ✔✔N α constrict, reducing
blood flow; β₂ dilate, increasing blood flow
Explain the difference between an agonist and an antagonist. - correct answer ✔✔N Agonists exhibit the
same response as the ligand, whereas antagonists occupy but do not activate the receptor
Explain the pathogenesis of cholera. What effect does it have on the molecules? - correct answer ✔✔N -
comes from contaminates *water*
- produce a toxin which affects the small intestine, yielding water loss
- disables intrinsic GTPase activity of α subunit
Explain the activity of GPCRs. What NXP does it have when "off?" When on? How does it inactivate?
What subunits are considered active? - correct answer ✔✔N - consists of a receptor portion, and then
an α and βɣ subunits; the βɣ seperate from the α.
- GDP when off
- GTP when on
- inactivates by hydrolysis of the terminal ℗
- βɣ yield activation
Which subinit does the GTP attach to? Which has GTPase activity? Does the GPCR attach another ℗, or
does it swap GDP to GTP for activation? - correct answer ✔✔N - GTP on α
- α has GTPase activity
- GDP is exchanged for GTP for activation
What is the time span for Gα GTP hydrolysis? What disease is implicated in failure of hydrolysis? - correct
answer ✔✔N Usually seconds; collera
Explain tonic control. Is it under parasympathetic control? - correct answer ✔✔N Δn_signals yielding a
∇ of signals
NOT under parasympathetic control; all modulation by Δn
What is physiology? - correct answer ✔✔N The science of the function of living system
What is the difference between process and function? - correct answer ✔✔N - process = "how"
- function = "why"
What is homeostasis with respect to a fluid? - correct answer ✔✔N Maintenance of a relatively stable
internal cellular fluid
Who coined the term "homeostasis?" - correct answer ✔✔N Walter Cannon
What is pathophysiology? - correct answer ✔✔N The study of when systems fail to compensate
What is local control? Reflex control? What modulates reflex control? - correct answer ✔✔N - local
control = changes near the site of damage
- reflex control = over long distances; managed by the CNS
List some examples of variables monitored by the CNS - correct answer ✔✔N - osmolarity
-T
- BP
What are the three types of feedback mechanisms? Which is most common? least common? - correct
answer ✔✔N Negative, positive and feedforward. Negative feedback →negative very common
→positive very rare
What is responsible for most communication - electrical or chemical signals? - correct answer ✔✔N
Chemical
,Define target cells WRT sent signals. - correct answer ✔✔N Target cells are those cells which are able to
respond to chemical signals, and contain a receptor for it.
What are forms of long-range cell-cell communication? - correct answer ✔✔N endocrine (chemical
hormone), neural and neuro endocrine (chemicals at axon terminal secrete into the bloodstream).
Where are ligand receptors located? What do these specific locations yield in terms of function? - correct
answer ✔✔N A *protein* which projects outside of the membrane or are within the membrane;
hydrophobic ligands will diffuse into the cytoplasm; hydrophilic via an intracellular receptor (consider the
lipo and hydrophobicity WRT location)
name the three main types of membrane receptors covered in 373. - correct answer ✔✔N - ion channel
- enzyme-coupled receptor
- GPCR
What are the main types of second messengers? Name a representative member of each. - correct
answer ✔✔N - nucleotides; cAMP
- lipid-derived molecules; IP_3
- ions; Ca²⁺
How can one signal have different effects on different cell types? - correct answer ✔✔N One ligand may
have several different types of receptors
What aspects of kinetics and thermodynamics affect ligand-receptor interactions? - correct answer ✔✔N
K_eq (rel. affinity), saturation
How can cells change their response to signals? - correct answer ✔✔N - ↑ n_receptors by changing
receptor number or sensitivity
- ↓ n_receptors by internalizing the surface protein
*- Δsensitivity by ℗*
, What are the effects of Epi on α receptors? β₂ receptors? - correct answer ✔✔N α constrict, reducing
blood flow; β₂ dilate, increasing blood flow
Explain the difference between an agonist and an antagonist. - correct answer ✔✔N Agonists exhibit the
same response as the ligand, whereas antagonists occupy but do not activate the receptor
Explain the pathogenesis of cholera. What effect does it have on the molecules? - correct answer ✔✔N -
comes from contaminates *water*
- produce a toxin which affects the small intestine, yielding water loss
- disables intrinsic GTPase activity of α subunit
Explain the activity of GPCRs. What NXP does it have when "off?" When on? How does it inactivate?
What subunits are considered active? - correct answer ✔✔N - consists of a receptor portion, and then
an α and βɣ subunits; the βɣ seperate from the α.
- GDP when off
- GTP when on
- inactivates by hydrolysis of the terminal ℗
- βɣ yield activation
Which subinit does the GTP attach to? Which has GTPase activity? Does the GPCR attach another ℗, or
does it swap GDP to GTP for activation? - correct answer ✔✔N - GTP on α
- α has GTPase activity
- GDP is exchanged for GTP for activation
What is the time span for Gα GTP hydrolysis? What disease is implicated in failure of hydrolysis? - correct
answer ✔✔N Usually seconds; collera
Explain tonic control. Is it under parasympathetic control? - correct answer ✔✔N Δn_signals yielding a
∇ of signals
NOT under parasympathetic control; all modulation by Δn
