1. Saturday Study Session 2 Theme of the day: Information Transfer
Session 1 – Cell signaling, Endocrine system, and Thermoregulation

2. Clue: source = Starting point
Question 1 Answer D
Clue: source = Starting point
Please help students understand the relationship between the steps and the possible answers. This one word should narrowing thinking down immediately to answers C and D.

3. Step 1: Reception
Please remind students that ligands can be molecules or forms of Energy. If a molecule, molecules have distinct shapes and masses. If forms of energy, light, wave, pressure, etc.

4. Step 2: Transduction
Please stress the need for conformational shape change. This identifies if this is the target tissue or not. If no conformational shape change occurs in the receptor protein; that is not the intended target.

5. Step 3: Response
Make sure students understand it is either an enzyme being turned off/on or a process, such as transcription or replication, being turned on/off.

6. Clue: secondary = inside
Question 2 answer C
Clue: secondary = inside

7. Secondary Messenger First messenger (signal molecule
such as epinephrine)
Adenylyl
cyclase
G protein
G-protein-linked
receptor
GTP
ATP
Second
messenger
cAMP
Help students see the location and role
Protein
kinase A
Cellular responses

8. Secondary Messenger cAMP
Adenylyl cyclase
Phosphodiesterase
Pyrophosphate
H2O P P i
ATP
Cyclic AMP
AMP
Please help students see this is an RNA Adenine molecule that has circled up. It could also be an ATP or ADP that has lost phosphates.

9. Clue: through the plasma membrane
Question 3 answer A
Clue: through the plasma membrane

10. Intracellular receptors
Please remind students that secondary messengers are different from hormone (lipid based) ligands which can diffuse across the lipid bi-layer and meet up with its receptor protein. This are mostly associated with transcription of mRNA to generate protein synthesis.

11. Clue: numerous hormones to help regulate
Question 4 answer B
Clue: numerous hormones to help regulate
Please help students understand this concept. If there exists numerous hormones to help regulate, then chances are good the all do something different.

12. Examples of Negative Feedback Loops
Hypothalamus
TRH
Anterior
pituitary
TSH
Please just stress that a molecule in excess is traveling back to in activate a process the is in action currently.
Thyroid T3 T4

13. Positive Feedback Loop
Please just focus on the fact that an end product is going back an amplifying a process that is currently in action.

14. Staying between the lines of life by using antagonistic signals.
Death may occur out here. _________________________________ Life Can exist. State rises toward limit; so process is stopped by a signal andgets going in the opposite direction. Approach other limit so stopped and reversed by another signal _________________________________

15. Clue: antagonistic hormones
Question 5 answer C
Clue: antagonistic hormones
Answer A is incorrect because Thyroxine is metabolism and PTH is calcium. Calcitonin would be the PTH antagonist.
Answer B is incorrect because Oxytocin and Prolactin are synergistic in the breast during lactation.
Answer D is incorrect because Progesterone and estrogen are complimentary in female reproductive cycles.

16. Blood Glucose regulation in the human body
Body cells
take up more
glucose.
Insulin
Beta cells of
pancreas
release insulin
into the blood.
Liver takes
up glucose
and stores it
as glycogen.
STIMULUS:
Rising blood glucose
level (for instance, after
eating a carbohydrate-
rich meal)
Blood glucose level
declines to set point;
stimulus for insulin
release diminishes.
Homeostasis:
Blood glucose level
(about 90 mg/100 mL)
Blood glucose level
rises to set point;
stimulus for glucagon
release diminishes.
STIMULUS:
Dropping blood glucose
level (for instance, after
skipping a meal)
Please make sure students understand the liver is the storage organ and the hormone source is the pancreas.
Alpha cells of pancreas
release glucagon into
the blood.
Liver breaks
down glycogen
and releases
glucose into the
blood.
Glucagon

17. Clue: effector = bodily
Question 6 answer A
Clue: effector = bodily
Please help students understand the difference between answer A and answers B and C. B and C are not bodily functions. They are behaviors that must be initiated, such as let me do some jumping jacks or let me move into the sun. Shivering is an non-mental response (autonomic). It happens on its own. Answer D is a positive feedback loop.

18. Internal body temperature
Temperature control
Thermostat in
hypothalamus
activates cooling
mechanisms.
Sweat glands secrete
sweat that evaporates,
cooling the body.
Blood vessels
in skin dilate:
capillaries fill
with warm blood;
heat radiates from
skin surface.
Increased body
temperature (such
as when exercising
or in hot
surroundings)
Body temperature
decreases;
thermostat
shuts off cooling
mechanisms.
Homeostasis:
Internal body temperature
of approximately 36–38°C
Body temperature
increases;
thermostat
shuts off warming
mechanisms.
Decreased body
temperature
(such as when
in cold
surroundings)
Please explain and stress the hypothalamus’ role in temperature regulation.
Blood vessels in skin
constrict, diverting blood
from skin to deeper tissues
and reducing heat loss
from skin surface.
Thermostat in
hypothalamus
activates
warming
mechanisms.
Skeletal muscles rapidly
contract, causing shivering,
which generates heat.

19. Math Grid In Answer The answer is: 50 mLs. Soulution: Ci Vi = Cf Vf
Therefore, (1.0 M)(?) = (0.05 M)(1000mL)
? = (0.05 M)(1000 mL)
(1.0 M)
? = 50 mL

20. Short Free Response 1 (4 points possible)
Possible points awarded for:
Discussion of negative back being a process in action being stopped and another process taking in in the opposite direction. (1 pt.)
Example (1 pt.)
Discussion of positive being a process in action being amplified by a product of the same reaction. (1 pt.)

21. Examples of Negative Feedback Loops
Hypothalamus
TRH
Anterior
pituitary
TSH
Please just stress that a molecule in excess is traveling back to in activate a process the is in action currently.
Thyroid T3 T4

22. Positive Feedback Loop
Please just focus on the fact that an end product is going back an amplifying a process that is currently in action.

23. Short Free Response 2 (3 points possible)
Possible points awarded for:
Discussion of reception being a ligand binding to a receptor protein. (1 pt.)
Discussion of Transduction being a conformational shape change sets in motion of changing the signal into something a cell can “understand”. (1 pt.)
Discussion of response being the cell “understanding” the signal and altering its behavior/function. (1 pt.)

24. Signal Transduction Response
Make sure students understand it is either an enzyme being turned off/on or a process, such as transcription or replication, being turned on/off.