BIOL 373 || Error-free Answers 100%.
What is physiology? correct answers The science of the function of living system
What is the difference between process and function? correct answers - process = "how"
- function = "why"
What is homeostasis with respect to a fluid? correct answers Maintenance of a relatively stable
internal cellular fluid
Who coined the term "homeostasis?" correct answers Walter Cannon
What is pathophysiology? correct answers The study of when systems fail to compensate
What is local control? Reflex control? What modulates reflex control? correct answers - 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 answers - osmolarity
-T
- BP
What are the three types of feedback mechanisms? Which is most common? least common?
correct answers Negative, positive and feedforward. Negative feedback →negative very common
→positive very rare
What is responsible for most communication - electrical or chemical signals? correct answers
Chemical
,Define target cells WRT sent signals. correct answers 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 answers 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 answers 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 answers - ion channel
- enzyme-coupled receptor
- GPCR
What are the main types of second messengers? Name a representative member of each. correct
answers - nucleotides; cAMP
- lipid-derived molecules; IP_3
- ions; Ca²⁺
How can one signal have different effects on different cell types? correct answers One ligand
may have several different types of receptors
What aspects of kinetics and thermodynamics affect ligand-receptor interactions? correct
answers K_eq (rel. affinity), saturation
How can cells change their response to signals? correct answers - ↑ 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 answers α constrict, reducing
blood flow; β₂ dilate, increasing blood flow
Explain the difference between an agonist and an antagonist. correct answers 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 answers
- 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 answers - 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 answers - 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 answers Usually seconds; collera
What is physiology? correct answers The science of the function of living system
What is the difference between process and function? correct answers - process = "how"
- function = "why"
What is homeostasis with respect to a fluid? correct answers Maintenance of a relatively stable
internal cellular fluid
Who coined the term "homeostasis?" correct answers Walter Cannon
What is pathophysiology? correct answers The study of when systems fail to compensate
What is local control? Reflex control? What modulates reflex control? correct answers - 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 answers - osmolarity
-T
- BP
What are the three types of feedback mechanisms? Which is most common? least common?
correct answers Negative, positive and feedforward. Negative feedback →negative very common
→positive very rare
What is responsible for most communication - electrical or chemical signals? correct answers
Chemical
,Define target cells WRT sent signals. correct answers 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 answers 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 answers 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 answers - ion channel
- enzyme-coupled receptor
- GPCR
What are the main types of second messengers? Name a representative member of each. correct
answers - nucleotides; cAMP
- lipid-derived molecules; IP_3
- ions; Ca²⁺
How can one signal have different effects on different cell types? correct answers One ligand
may have several different types of receptors
What aspects of kinetics and thermodynamics affect ligand-receptor interactions? correct
answers K_eq (rel. affinity), saturation
How can cells change their response to signals? correct answers - ↑ 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 answers α constrict, reducing
blood flow; β₂ dilate, increasing blood flow
Explain the difference between an agonist and an antagonist. correct answers 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 answers
- 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 answers - 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 answers - 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 answers Usually seconds; collera
