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Flashcards in INtegrated Metabolism Deck (20):
1

RBC

Its fuel reserve?

GLUT?
1. Define the major metabolic pathways of the major organs  consistent with their function.
2.List the possible metabolic fuels and energy reservoirs for the major organ
 

RBC= No fuel reserve-- remember no mitochondria, so no TCA

RBC glucose through GLUT 1

 

Major pathways glucose-- hexokinase-- glucose 6P

 

Glucose 6P can enter the PPP patwhy or Lactate-- Cori Cycle

 

Through 1-3 BPG it can make 23 BPG producing lesser ATP by its glycolysis

2

 

BRAIN

 

Its fuel reserve?

GLUT?
1. Define the major metabolic pathways of the major organs  consistent with their function.
2.List the possible metabolic fuels and energy reservoirs for the major organ

Very little fuel reserve, so it always needs supply of glucose

- GLut 3 and Glut 1 for BBB

 

high respiratory metaboism (uses 20% of the O2)

 

At Glucose G-6P junctions can go to

1. PPP to make NADPH

2. Pyruvate-- PDH--> Acteyl Coa--- TCA

 

** ketone bodies can come from liver into acetyl CoA when glucose deprived**

 

3

 

Skeletal and Heart Muscle

 

Its fuel reserve?

GLUT?
1. Define the major metabolic pathways of the major organs  consistent with their function.
2.List the possible metabolic fuels and energy reservoirs for the major organ

Reserve-

 

Skeletal muscle---phosphocreatin and 2% of glycogen storage and during excessive exerise can use its AA to pyruvate/AcCoA to enter TCA and Alanine goes to liver for production of glucose

 

Heart-- very low storage of phosphocreatin and glycogen and prefers fatty acid as energy but when starving uses glucose from liver, ketone bodies from liver, and FA from adipose

uses glut- 4 which is insulin induced.

 

At Glucose 6-P can heart and skeelta ...

1. Go to glycogen storage

2. Go to PPP and make NADPH

3. Go to pyruvate and turn to lactate (when anerobic)

4. Go to pyruvate then AcetylCoA then TCA

4

 

Adipose

 

Its fuel reserve?

GLUT?
1. Define the major metabolic pathways of the major organs  consistent with their function.
2.List the possible metabolic fuels and energy reservoirs for the major organ

Storge- TAG storage is 65% of it's weight can acounts for 3 months of energy supply

 

Uses GLut 4-- insulin stimulated (like cardiac and skeletal)

Preferred energy-- Uses glucose and makes AcCoA for FA synthesis and the NADPH from the PPP. Also takes up FA from the liver

When Starving-- releases it's FA to blood

 

At Glucose 6P can go to

1. GLycogen

2. PPP

3. Pyruvate to Acetyl CoA to lipogensis and fat storage

5

What's special about brown fat

A lot in babies. This causes protons to reenter the mitochondria so it makes heat instead of ATP.

 

Oxidizes FA to make heat

6

LIVER

 

Its fuel reserve?

GLUT?
1. Define the major metabolic pathways of the major organs  consistent with their function.
2.List the possible metabolic fuels and energy reservoirs for the major organ

Reserve- glycogen and can run glucogenolysis frm lactate, AA or glycerol during fasting

 

Glut 2-- glucose enters and leaves through this receptor

 

Glucose 6-P

1. GLycogen

2. PPP- to make NADPH

3. Pyruvate to LActate (normal lactate is coming in from muscle and feeding in for gluconeogensis because liver isn't normally without O2)

3. Pyruvate to Acetyl COa to TCA

5. Acetyl CoA to Fat (VLDL) sent to adipose

7

Effects of hormones

Covalent modication of enzymes

Induction-repression of enzymes synthesis

 

So systems not affected by hormones (RBC) can't have this done by hormones.

8

Target tissues of 4 main hormones


Target tissues:
Insulin: liver, muscle, adipose tissue
Glucagon: liver, adipose tissue
Epinephrine: liver, muscle, adipose tissue
Glucocorticoids: liver, muscle, adipose tissue
 

9

Metabolic processes stimulated by insulin

Dephos- normally anablic

 

GLycogen

Glycolysis (which increase FA synthesis)

Lipogenissi

Cholesterol Syn

AA synthessi


Promotes TG storage in adipose

Promotes glucose uptake by adipose and msucle

10

Metabolic processes stimulated by glucagon

Gluconeogensis/inhibts gylysis

Glycolysis/inhibits glycogen storage

Lipolysis in adipose

Degradtion of AA

Inhibits FA synthesis

11

What does epi mostly effect

The msucles. Similiar to glucagon (but glucagon doesn't affect hte muscles).

 

Promotes release of glucose from the liver

stimulates glycogenolysis and lipolysis

12

How to hormones in circulating blood regulate each other

Epi would be high under stress/bur/trauma/cold/low blood glucose and it would down ergulated insulin and upregulate glucagon

13

4 types of hypoglycemia

1. Insulin induced- too much insulin administered so drives blood glucose down-- give oral glucose or inject glucagon

2. Postprandal- post meal insulin shoots up too high-- eat smaller meals to prevent

3. Fasting hypoglycemis-- shouldn't happening because our bodies should compensate when fasting but if B-cells have tumor and insulin is too high or if hepatocytes are necrotic. Also in G-6_phosphatase defieicny glycogen or gluconeogensis can't supply glucose.

4. Alcohol induced- ehtnaol breaks down by Alchol DH which makes an NADH. This NADH pushes intermediates of TCA to other intermedias like pyruvate to lactate instead of TCA and the cell is starving for energy.

14

What happens after a meal

Insulin is HIgh

Glucagon, Epi and Glucocorticods are low

 

We store-- glycogenesis in liver and muscle, lipogensis in adipose, glycsolysis for FA syntehsis, PPP for FA synthesis, increase choelsterold and increase AA

 

Liver- glycolysis, glycogensis, lipogensis (for VLDL), PPP

Muscle- glycolysis, glycogensis

Adipose- Lipogensis (and storage_, glycoslysis, PPP

15

Between meals

Insuling- low

Glucagon, Epi- high

 

Liver- glycogenosis, glucogensis, Cori and Ala cycles

Adipose- NOTHING aren't starving yet

Muscle- glycogenolysis, glycolysis, Ala cycle

 

main source is glycogen and gluconeogensis

16

Early Fasting .5-2 days

Insulin- none

Epi, Gluccagon, Glucocoticoids- high

T3- low but starts lowering metobolic rate

 

Liver- gluconeogensis upregulated, glycolysis, FA oxidation, ketogensis, urea cycle, cori and ala cycle

Adipose- lipolysis

Muscle- Glycogenolysis, proteolysis, FA oxidation, ketone body utilization

 

main energy- storage fat-ketone bodies for liver, msucle, kideny

Glucose- RBC, WBC, adrenal medulla, retina, BRAIN

17

Intermediate fasting 2-24 days

No incoming fuel from gut, all glycogen use, mobilize FAT

 

Liver- gluconeogensis, Cori and Ala cycles, ketone body synthesis, FA oxidation

 

Muscle- protelysis, FA oxidation, ketone body usage

 

Adipose- lioplysis

 

Main energy- brain- uses more ketone than glucose

RBC, WBC, retina, and adrenal medulla- glucose

Liver, kidney and msucles- stored fats

18

Starvation > 24 hours

Liver- gluconeogensis, FA oxidation, ketone body synthesis, cori cycle

 

Muscle- FA oxidation-- note we start conserving our proteins

 

Adipose- lipolysis

 

Main eneryg

 

Storage- liver, mscle, kidney

Glcuose- RBC, WBC, retina adrenal medule

Brain- mainly ketone

19

What happens when we're intially refed after starvation

Liver stays at gluconeogenci state for a while so glucose coming into liver is sent to organs and not stored as glycogn.

 

Takes a few hours to the glycolytic enzymes to comeback

20

5 phases of eating and proceses used to maintain blood glucose

 

1. Well fed- glycolysis-- glucose from diet (ALL cells)

2. Between meals- glycogenlysis (All except liver, less in adipose and muscle)

3. Early starvation- hepatic gluconeogensis (All except liver and less in adipose and muscle)

4. Stavation- FA, ketone bodies, gluconeogensis (brain, RBC, adrenal medulle, WBC, retina)

5. Prolonged starvation- FA, Ketone bodies and less gluconeogensis (less by brain-- it sstarts using ketone bodies)