Saturday Study Session 2Theme of the day:

Information TransferSession 1 – Cell signaling, Endocrine

system, and Thermoregulation

Question 1 Answer

DClue: source = Starting

point

Step 1: Reception

Step 2: Transduction

Step 3: Response

Question 2 answer

CClue: secondary = inside

Secondary Messenger

cAMP

ATPSecondmessenger

First messenger(signal moleculesuch as epinephrine)

G-protein-linkedreceptor

G protein

Adenylylcyclase

Proteinkinase A

Cellular responses

GTP

Secondary Messenger cAMP

ATP Cyclic AMP AMP

Adenylyl cyclase

PyrophosphateP P i

Phosphodiesterase

H2O

Question 3 answer

AClue: through the plasma

membrane

Intracellular receptors

Question 4 answer

BClue: numerous

hormones to help regulate

Examples of Negative Feedback Loops

Hypothalamus

TRH

Anteriorpituitary

TSH

Thyroid

T3 T4

Positive Feedback Loop

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 andgets going in the opposite

direction. Approach other limit so stopped and reversed by another signal _________________________________Death may occur out here.

Question 5 answer

CClue: antagonistic

hormones

Blood Glucose regulation in the

human body Beta cells ofpancreasrelease insulininto the blood.

Insulin

Liver takesup glucoseand stores itas glycogen.

STIMULUS:Rising blood glucose

level (for instance, aftereating a carbohydrate-

rich meal)

Blood glucose leveldeclines to set point;stimulus for insulinrelease diminishes.

Homeostasis:Blood glucose level

(about 90 mg/100 mL)

STIMULUS:Dropping blood glucoselevel (for instance, after

skipping a meal)

Blood glucose levelrises to set point;

stimulus for glucagonrelease diminishes.

Liver breaksdown glycogenand releasesglucose into theblood.

Body cellstake up moreglucose.

Alpha cells of pancreasrelease glucagon into the blood.

Glucagon

Question 6 answer

AClue: effector = bodily

Temperature controlThermostat inhypothalamusactivates coolingmechanisms.

Increased bodytemperature (suchas when exercising

or in hotsurroundings)

Body temperaturedecreases;thermostat

shuts off coolingmechanisms.

Sweat glands secretesweat that evaporates,cooling the body.

Blood vesselsin skin dilate:capillaries fillwith warm blood;heat radiates fromskin surface.

Body temperatureincreases;thermostat

shuts off warmingmechanisms.

Decreased bodytemperature

(such as whenin cold

surroundings)

Blood vessels in skin constrict, diverting bloodfrom skin to deeper tissuesand reducing heat lossfrom skin surface.

Skeletal muscles rapidlycontract, causing shivering,which generates heat.

Thermostat in hypothalamusactivateswarmingmechanisms.

Homeostasis:Internal body temperatureof approximately 36–38°C

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

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.)

• Example (1 pt.)

Examples of Negative Feedback Loops

Hypothalamus

TRH

Anteriorpituitary

TSH

Thyroid

T3 T4

Positive Feedback Loop

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.)

Signal Transduction Response