Integration Of Metabolism

Question 1

Leptin

Answer 1

• secreted by ADIPOCYTES
• Reports on the status of TAG stores
• Represses the desire to EAT

Question 2

Where does EXCESS TAG get stored?

Answer 2

1. Pancreas
2. Muscles
3. Liver
4. Blood vessels

Question 3

Fxn of Ghrelin

Answer 3

• Peptide secreted by the Stomach

- Acts on the Hypothalamus to stimulate APPETITE through its receptor

Question 4

SOCS Knockout mice display what?

Answer 4

1. Enhanced sensitivity to Leptin
2. Resistance to weight gain
   - even with a high fat diet

Question 5

Type 1 Diabetes

Answer 5

Autoimmune DESTRUCTION of Beta cells

• Usually before the age of 20

Question 6

Mnemonic for Leptin

Answer 6

Leptin won’t “Let Him” eat.

• So won’t “MS. H”

Question 7

What kind of receptor does Insulin bind to?

Answer 7

Tyrosine-Kinase Receptor

Question 8

Leptin binds to what kind of receptor in the Hypothalamus?

Answer 8

Arcuate Nucleus

Question 9

Insulin deficiency or resistance can lead to what?

Answer 9

• Hyperglycemia
• Metabolic Syndrome
• Diabetes

Question 10

GLP-1

Answer 10

• Glucagon-like Peptide 1
• Secreted by “L” cells in the INTESTINE
• Increases INSULIN secretion
• Increases insulin BIOSYNTHESIS
• Acts on the brain to induce the feeling of SATIETY

Question 11

Ghrelin secretion increases _____ and decreases _____.

Answer 11

• BEFORE a meal

- AFTER a meal

Question 12

Upon Leptin binding to it’s receptor, POMC is proteolytically processed to yield variety of signal molecules one of which is ______?

Answer 12

Melanocyte-Stimulating Hormone

Question 13

Fxn of Leptin

Answer 13

1. Increase the sensitivity of MUSCLE and LIVER to Insulin
2. Stimulates Beta Oxidation of FA
3. Decreases TAG Synthesis

Question 14

A knockout in Leptin will lead to what?

Answer 14

Extreme Obesity

• Hyperphagia (Overeating)
• Hyperlipidemia
• Insensitivity to Insulin

Question 15

When ATP is LOW, AMPK is _______?

Answer 15

Allosterically Activated

&

Phosphorylates many targets controlling cellular energy production and consumption

Question 16

When ATP is HIGH, AMPK is ______.

Answer 16

INACTIVE

Question 17

Type 2 Diabetes

Answer 17

• Normal or even HIGHER levels of Insulin in the blood

- Unresponsive to Hormone (Resistance)

Question 18

Both Leptin and Adiponectin exert their effects through the Key regulatory enzyme, ________.

Answer 18

AMP- Activated Protein Kinase (AMPK)

Question 19

Energy Consumed equals what?

Answer 19

Energy EXPENDED

+

Energy STORED

Question 20

SOCS

Answer 20

Suppressor of Cytokine Signaling

• Disrupts the interactions of components of the Insulin-signaling pathway (Inhibits)

Question 21

What enzyme is the “Tallest building that would be seen at 30k feet?”

Answer 21

AMPK

Question 22

Where is energy stored in the body?

Answer 22

In TAG in the Adipocytes

Question 23

What is a second population of neurons containing Leptin?

Answer 23

Proopiomelanocortin (POMC)

Question 24

AMPL Activates what pathway?

Answer 24

FA Oxidation

Question 25

Insulin

Answer 25

- secreted by the Beta cells of the Pancreas | - Reports on the status of Blood glucose

Question 26

Obesity can be cause by a resistance to what?

Answer 26

Leptin &/or Insulin

Question 27

Long term control over caloric homeostasis.

Answer 27

2 key signal molecules regulate energy homeostasis over the time scale of HOURS to DAYS - Leptin and Insulin

Question 28

What is the only organ that can carry out all the reactions of major pathways?

Answer 28

Liver

Question 29

CCK binds to what type of receptor? Where?

Answer 29

- Binds to G-protein-coupled receptors | - Located in various peripheral NEURONS

Question 30

What turns OFF the Insulin Signal?

Answer 30

A bunch of Phosphatases

Question 31

Overview of Diabetes Mellitus

Answer 31

- Glucose is OVER produced by the LIVER | - Glucose is UNDERUTILIZED by other organs

Question 32

Mnemonic for AMPK

Answer 32

Want to eat at “AMP......K”

Question 33

Short-term Signals to induce satiety?

Answer 33

Relay the feelings of Satiety from the GUT to various regions of the BRAIN - Reduces the urge to eat - Use of CCK and GLP-1

Question 34

CCK

Answer 34

- Cholecystokinin - Secreted by the SMALL Intestine in response to a meal - Acts on the brain to induce the feeling of SATIETY - Can also potential INSULIN action in the Pancreas - Stimulates the secretion of BILE Salts from the Gallbladder

Question 35

What population of neurons expresses appetite-stimulating peptides?

Answer 35

- Neuropeptide Y (NPY) - Agouti-related Peptide (AgRP) (“Pie & AGRaPe)

Question 36

Leptin is secreted in DIRECT proportion to what?

Answer 36

The amount of FAT present.

Question 37

Leptin secretes signal molecules called _____?

Answer 37

Adipokines | - Leptin and Adiponectin

Question 38

Most short-term signals are _______?

Answer 38

Appetite suppressants

Question 39

CCK is secreted as a ______ signal.

Answer 39

Postprandial

Question 40

What does Leptin inhibit?

Answer 40

NPY and AgRP - Represses the desire to eat