Link Reaction 18.2 Flashcards
Name the main parts of the mitochondria
- Outer mitochondrial membrane
- Intermembrane space
- Inner mitochondrial membrane
- Cristae
- Matrix
Outer mitochondrial membrane
Separates contents of mitochondria from the rest of the cell so that it is the optimum conditions for respiration
Intermembrane space
The electron transport chain pumps protons into here. The space is small so that the concentration builds up quickly
Inner mitochondrial membrane
This is where the electron transport chain is located and it contains hydrophilic membrane channels
Matrix
Contains mitochondrial DNA and many enzymes for the Krebs cycle and link reactions
Cristae
Projections of the inner mitochondrial membrane that increases surface area for oxidative phosphorylation
Where does the link reaction occur?
In the mitochondrial matrix
What is needed for the link reaction to occur?
ATP and oxygen
Describe what happens during the Link reaction
Pyruvate is actively transported from the cytoplasm to the mitochondrial matrix which is why ATP and oxygen are needed.
- Pyruvate is oxidised by NAD+ which becomes NADH
- It then has a carbon dioxide removed which is called decarboxylation and an acetyl group is formed ( 2 carbons).
- The Co2 is removed as waste
- The acetyl group is combined with coenzyme A to form acetyl CoA which is used later.
What is the role of NAD?
It is a coenzyme that carries hydrogens and uses them and accepts them to take part in redox reactions. The enzyme it assists is dehydrogenase enzyme
Why does glycolysis not occur in the mitochondria?
- Glucose too big move into the mitochondria
- Inorganic phosphate ions are needed from the cytoplasm
- No transport proteins for pyruvate in the mitochondria