Energy Metabolism Flashcards
How does the body extract energy from carbs?
Anaerobic and Aerobic pathways
How does the body extract energy from fats?
Beta-oxidation
How does the body extract energy from proteins?
Deamination
Catabolism
Metabolic reactions break down molecules to extract energy
Anabolism
Metabolic reactions synthesize building blocks to produce new molecules
Carb usual energy from 4 pathways
- Glycolysis- cytosol
- Pyruvate to acetyl CoA- Mitochondria
- Citric Acid Cycle- Mitochondria
- ETC- Mitochondria
Glycosis- Glucose splitting
One six-carbon glucose molecule into two three-carbon pyruvate molecules
Where does glycolysis occur?
Cytosol
How much ATP does glycolysis use and produce?
Uses 2 ATP and Produces 4 ATP = 2 net ATP
Pyruvate to Lactate
When O2 is in short supply, pyruvate forms lactate
Lactate
Alternative fuel that muscle cells can use or that the liver cells can convert to glucose through anaerobic pathways
Why Lactation?
Speed! Making ATP in the liver is very quick due to glycolysis
Pyruvate to Acetyl CoA
Two pyruvate molecules from 1 molecule of glucose, produce two acetyl CoA molecules
Why is Pyruvate to Acetyl CoA irreversible?
Acetyl CoA cannot exit via the mitochondrial membrane & enters the citric acid cycle in the mitochondria
Citric Acid Cycle
Acetyl CoA combines with oxaloacetate to form citrate and release coenzyme A. The two carbon atoms from acetyl CoA combine with O2 to form CO2
What does the Citric Acid Cycle produce?
- One guanosine triphosphate (GTP)
- Transfer pairs of high energy electrons to 3 molecules of NAD+ and 1 molecule of FAD
- Oxaloacetate is regenerated
One glucose molecule produces two acetyl CoA molecules, the citric acid cycle occurs twice
Electron Transport Chain
- NADH AND FADH2 deliver their cargo of high-energy electrons to the ETC
- As electrons travel along the ETC they give up energy to power the production of ATP
What is at the end of the ETC?
An oxygen “basket” accepts the energy-depleted electrons and combines them with hydrogen to form water
What if there was no oxygen for the ETC to use?
ATP production would stop halting the supply of power for our body’s essential functions
How do electrons travel along the ETC?
They move from higher to lower energy levels, releasing energy
How is an electrochemical gradient created in the ETC?
Some of the energy that is released is used to pump H+ ions out of the matrix and into intermembrane space, establishing an electrochemical gradient due to charge
Where do the H+ ions in the ETC go?
H+ ions flow down the gradient powering ATP synthase
Beta-oxidation of fatty acids
Acetyl CoA enters the Citric acid cycle to generate NADH and FADH2 for transferring pairs of high energy electrons to ETC to fuel ATP synthesis in the mitochondria
How do fatty acids travel across the mitochondria membrane?
Carnitine transport
