next is the Krebs Cycle. This is when energy is extracted from the sugar
Preparatory phase steps:1. As each pyruvic acid is broken down, a pair of electrons(and proton) are passed to NAD, producing NADH2. A carbon and 2 oxygen atoms get released as Co23. Coenzyme A itself to remaining molecule , creating Acytal CoA
The preparatory phase is very important. Pyruvic acid become something called Acytal CoA.
this is happening in the mitochondrial matrix
used by aerobic organisms!
2 ATP, 8 NADH, 2 FADH2 formed
Great! So after Acytal CoA is made the main steps of the Kreb cycle begin.
3. oxaloacetate is re-formed, ATP generated, and more high-energy electron carriers are formedthe remaining 4 carbon molecule is rearranged to form oxaloacetate. ATP is formed, and electrons are passed to NADH and FADH2
1. An Acetyl CoA molecule enters the cycle and binds to oxaloacetate, creating a 6 carbon molecule
2. the 6 carbon molecule donates electrons NAD+, creating NADH. Two Co2 molecules are released into the atmosphere
this is happening in the inner mitochondrial matrix
After the Krebs Cycle, there is another ETC, just like in photosynthesis!
1. the electrons fall to a lower energy state, which releases energy2. the energy is used to power proton pumps, which pack H+ ions from the mitochondrial matrix into the inter-membrane space 3. At the end of the chain, the lower energy electrons are handed off to oxygen- which then combines with free H+ to make water 4. The protons rush back into the mitochondrial matrix with lots of kinetic energy, which can be used to build ATP