Integration of metabolism Flashcards

1
Q

glucose-6-phosphate is a metabolic junction point for what molecules?

A

glycogen

pyruvate

ribose-5-P

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2
Q

pyruvate is a metabolic junction point for what molecules?

A

acetyl-CoA

lactate

alanine

OAA
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3
Q

acetyl-CoA is a metabolic junction point for what molecules?

A

CO2

fatty acids

ketone bodies

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4
Q

What are the sources for pyruvate?

A

carbs +monosaccs

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5
Q

Sources for Acetyl Coa

A

AA

FA

pyruvate

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6
Q

Energy sources for adipose?

A

Glucose and fatty acids

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7
Q

Energy sources for Muscles?

A

Glucose, fatty acids, amino acids

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8
Q

Energy source for liver?

A

Fatty acids

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9
Q

Energy source for brain?

A

Glucose and ketone bodies

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10
Q

What does the liver metabolize?

A

Synthesizes and secretes proteins

Processes toxins and wastes

Maintains constant concentrations of nutrients

Amino acids go directly to the liver through the portal vein after absorption

Primarily depends on β-oxidation of fatty acids

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11
Q

What does adipose do?

A
  1. Synthesizes and stores triglycerides as signaled by insulin (fed state)
  2. Releases fatty acidsand glycerol as signaled by glucagon/epinephrine (hunger, exercise)
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12
Q

Whats significant about brain energy?

A
  • High dependence on blood glucose
  • Uses 20% of total O2 consumed by resting human (only 2% of body mass)
  • After days of low glucose consumption, switches to metabolism of ketone bodies for energy needs
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13
Q

What is significant about heart energy?

A

No glycogen stores

Lack of O2 leads to tissue death (myocardial infarction)

Cardiac muscle is exclusively aerobic

Glucose, lactate, fatty acids, and ketone bodies serve as fuel

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14
Q

What is significant about skeletal muscle energy?

A
  • Rich in glycogen (contains 75% of the body’s glycogen stores)
  • uses G-6-P for energy
  • Uses fatty acids and ketone bodies for energy
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15
Q

What is phosphagen system used for?

A

regeneration of ATP by phosphocreatine

Quick exhaustion of ATP stores

Replenished by metabolism of phosphocreatine

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16
Q

What is Anaerobic Glycolysis used for?

A

intense activity for like 30 seconds, makes pyruvate which becomes lactate eventually

17
Q

What is Oxidative Phosphorylation ?

A

ETC in mitochondria, coenzymes reduced

Production of energy from the oxidation of coenzymes NADH, FADH2

18
Q

What is energy charge?

A
  • ratio of ATP to ADP

- ratio high in energy-rich cells, low in cells that are low in energy

19
Q

What is reducing power?

A

- It represents the potential energy and varies inversely to the [ATP]:[ADP] ratio.

20
Q

What are CCK and GLP1?

A

Satiation signals that induce feelings of satiety in the brain, insulin action in pancreas

21
Q

What does CCK do?

A

secreted in SI , binds to GPCR in brain, feeling of satiety, helps with digestion

22
Q

what is Ghrelin?

A

secreted by stomach, acts on regions of the hypothalamus to stimulate appetite

23
Q

What does Leptin do?

A

Secreted by adipose tissue in direct proportion to fat mass

leptin receptor

  • Inhibits food intake
  • Stimulates energy expenditure
24
Q

What hormones affect long term control over caloric intake?

A

Leptin + Insulin

25
Q

What does the liver do during the fed state ?

A
  • Glycolysis
  • Glycogen synthesis
  • TG synthesis
26
Q

What does the liver do during the fasting state?

A
  • Glycogenolysis
  • Gluconeogenesis
  • Fatty Acid Oxidation
  • Ketone Body Formation
27
Q

When is insulin released and what does it lead to?

A

released in the fed state, when there is high glucose

  • high glucose uptake
  • glycogen synthesis
  • decrease glycogen breakdown
  • increase fatty acid and TAG synthesis
  • decrease gluconeogenesis
28
Q

When is glucagon released and what does it do?

A

when there is low blood glucose, opposite of insulin

29
Q

What effects does epi have on metabolism?

A

-increase heart rate, blood pressure and respiratory dilation

  • increase glycogen breakdown
  • decrease glycogen synthesis
  • increase glycolysis
  • increase gluconeogenesis
  • increased glucagon, decreased insulin
30
Q

What is the energy sensor in cells?

A

AMP-activated protein kinase (AMPK)

–When ATP is high, AMPK is inactive

–When ATP is low, AMPK is allosterically activatedand phosphorylates many targets

-competition between ATP and AMP for binding to the AMPK allosteric sites

31
Q

What does Leptin and adiponectin do to AMPK?

A
  • increase food intake
  • increase FA oxidation and uptake
  • decrease FA synthesis, insulin secretion
  • decrease anabolism, increase catabolism