Biochem 3-07 Basics Of Fuel Regulation

Front 1

Name the opposing, irreversible pathway:
Glycolysis

Back 1

Name the opposing, irreversible pathway:
Gluconeogenesis

Front 2

Name the opposing, irreversible pathway:
Glycogenesis

Back 2

Name the opposing, irreversible pathway:
Glycogenolysis

Front 3

Name the opposing, irreversible pathway:
Fatty acid synthesis

Back 3

Name the opposing, irreversible pathway:
Fatty acid oxidation

Front 4

Name the opposing, irreversible pathway:
Triglyceride deposition

Back 4

Name the opposing, irreversible pathway:
Triglyceride mobilization

Front 5

What are the usual targets of coordinated control (recicprocal regulation)?

Back 5

Committed enzymes

Front 6

What are two ways to regulate committed enzymes?

Back 6

-Phosphorylation/dephos.
-Allosteric activation/inactivation

Front 7

What is the committed enzyme in glycogenesis? In glycogenolysis?

Back 7

-Glycogen sythase
-Glycogen phosphorylase

Front 8

What secretes insulin?

Back 8

beta cells in pancreas

Front 9

In this list of hormones, pick out the one that's used during starvation (longer term effect):
Insulin
Glucagon
Catecholamines
Cortisol

Back 9

Cortisol

Front 10

What does insulin promote?

Back 10

-Transport glucose into adipose and muscle
-Glycogen synthesis in liver and muscle
-de novo TG synthesis in liver
-Lipogenesis (adipose tissue)
-Deposition of fat in adipose
-Protein synthesis (many tissues)

Front 11

Because insulin levels can fluctuate, what is the best way to determine how much insulin a pt's pancreas is secreating?

Back 11

Meausure the amount of C-peptide insulin the patient has. A and B chains are connected via disulfide bridges but in proinsulin, the C-peptide chain connects A and B chains.

Front 12

What is a "substrate cycle"?

Back 12

Another term for a futile cycle.

Front 13

Name two things that glucagon promotes.

Back 13

Glycogenolysis (in liver)
Lipolysis (in adipose tissue)

Front 14

How does insulin counteract glucagon and epinephrine?

Back 14

It activates protein phosphatases, whereas glucagon and epinephrine activates protein kinases.

Front 15

Give the pathway of events that glucagon triggers when there's low blood suger. Start in the pancreas. What's special about this form of signaling?

Back 15

-Pancreas secretes glucagon
-Glucagon binds to receptors in the cell membrane
-A second messeger (cAMP) is released in the cytosol
-cAMP activates a protein kinase
-Allows for amplification

Front 16

Where are catecholamines released from?

Back 16

Adrenal medulla

Front 17

What do catecholamines activate? (Name 2)

Back 17

-Glycogenolysis (liver, muscle)
-Lipolysis (adipose tissue)

Front 18

Why is cortisol appropriate for a longer response, rather than a fast response? What are some things that cortisol activates?

Back 18

-Acts at the gene level
-Gluconeogenesis, muscle protein breakdown, fat mobilization from adipose.

Front 19

When does cortisol start to kick in?

Back 19

After several days of physiological stress.

Front 20

What tissue is being described:
"Glycogen synthesis, convert glucose to FA and TG's, glycogenolysis, gluconeogenesis"

Back 20

Liver. The "altruistic hormone"

Front 21

What tissue is being described:
"Uses glycogen as fuel during exercise, replenishes glycogen during feast, does NOT break down glycogen to export glucose during fast"

Back 21

Muscle

Front 22

What tissue is being described:
"Deposits fat during feast, mobilizes fat during fast or exercise"

Back 22

Adipose

Front 23

What kind of hormones does the liver have receptors for?

Back 23

Insulin, glucagon, epinephrine

Front 24

What kind of hormones does the muscle have receptors for?

Back 24

Insulin and epinephrine.
NO RECEPTORS FOR GLUCAGON!!!

Front 25

What kind of hormones does adipose tissue have receptors for?

Back 25

Insulin, epinephrine, glucagon.

Front 26

In the liver, what hormone(s) causes triglyceride synthesis, glycogen synthesis, and glycolysis?

Back 26

Insulin. What to get glucose into the liver during fed state.

Front 27

In the liver, what hormone(s) cause glycogen degradation and gluconeogenesis?

Back 27

-Glucagon
-Epinephrine
-Cortisol
Want to get glucose out of the liver during fasting/starving state

Front 28

Does insulin promote the breakdown of TG's to FA's or promote the formation of TG's from FA's?

Back 28

Insulin promotes the formation of TG's from FA's

Front 29

Does insulin promote the breakdown of muscle into amino acids?

Back 29

No, insulin promotes protein synthesis from AA.

Front 30

What effect does glucagon have on muscle tissue?

Back 30

No effect, muscle tissue doesn't have receptors for glucagon!

Front 31

In the liver, does glucogon stimulate the storage of glucose as FA's?

Back 31

No, glucagon stimulates the liver to release glucose to add to the body's supply

Front 32

How do blood glucose, insulin, and glucagon levels changes after a high carb meal?

Back 32

Glucose up
Insulin up
Glucagon down

Front 33

How do blood glucose, insulin, and glucagon levels changes after a high protein, high fat, low carb meal?

Back 33

Glucose level
Insulin up (slightly)
Glucagon up

Front 34

What effect does insulin have on AA uptake and protein building?

Back 34

Insulin stimulates AA uptake into tissues for protein building.

Front 35

The homeostasis of glucose is one of the most important goals in metabolism. What are the effects of hyperglycemia?

Back 35

-Osmotic diuresis
-Glycation of hemoglobin (Amadori reaction)
-causes long term damage to microvasculature

Front 36

Describe the glycosylation of hemoglobin in the Amadori reaction (briefly!)

Back 36

-During the normal 120 day lifecycle of hemoglobin, it forms bonds with glucose that are readily reversible. This is known as Schiff base formation.
-In an individual who has long term hyperglycemia, the glucose/hemoglobin will undergo an irreversible isomerization to form the Amadori product, HbA1c.