4.4 Energy Metabolism Flashcards
What is the 1st step of energy metabolism?
Glycolysis
What happens during glycolysis?
Glucose is broken down into 2 pyruvate (a 3 carbon structure)
This produces 2 ATP and can sustain us for a little bit
What is the 2nd step of energy metabolism?
Pyruvate breakdown
What happens during Pyruvate breakdown?
Depends on whether we have enough O2 in the body
If we don’t have enough, it’s an anaerobic condition (sprinting, weight lifting, etc)
When in anaerobic condition pyruvate is broken down into lactate + some ATP (but not enough to sustain us). This process is reversible once O2 is available.
When in aerobic condition, pyruvate is broken down into acetyl CoA. This is the second stage of cellular respiration
What is the 3rd step of energy metabolism?
Citric Acid cycle/ Krebs cycle
What happens during the citric acid cycle?
Acetyl CoA combines with oxaloacetate (derived from carb intermediates)
Forms citrate. Then some sort of cycle happens where citrate is modified and then ultimately turned back into oxaloacetate. During the cycle, some GTP is produced and some electrons are released that are picked up by electron transports NADH+H^+ and FADH_2
What is the 4th step of energy metabolism?
Electron Transport Chain
What happens during the electron transport chain?
Takes place in the membrane of the mitochondria
Along membrane, there are proteins. The electron transports drop off electrons to the proteins and get passed back on forth
These are redox reactions, which drives a pump that allows the mitochondria to synthesize ATP via ATP synthase.
How are lipids integrated into cellular respiration?
Most are triglycerides, composed of 3 fatty acids and a glycerol molecule.
The glycerol molecules can be made into glucose.
The fatty acids molecules are clipped off 2 carbons at a time through beta oxidation and formed into acetyl CoA
How are proteins integrated into cellular respiration?
Proteins are composed of amino acids.
These amino acids are different due to side chains. The nitrogen group is clipped off via deamination and the remaining amino acid structure can come into the cycle at different points of time.
What is metabolism?
The sum of chemical reactions that occur in our bodies
What is anabolism?
Smaller molecules come together to form larger ones with an input of energy
What is catabolism?
Larger molecules are broken down into smaller ones, releasing energy
What is ketogenesis?
When fatty acids do not enter the citric acid cycle and instead form ketones
