Respiration Flashcards
What are the four key stages of respiration?
- Glycolysis
- Link Reaction
- Krebs Cycle
- Oxidative Phosphorylation
Where does glycolysis occur?
Cytoplasm
Where does the link reaction occur?
Mitochondrial matrix
Where does the Krebs Cycle occur?
Mitochondrial matrix
Where does oxidative phosphorylation occur?
Mitochondrial inner membrane / cristae
What does glycolysis produce?
Phosphorylated glucose (intermediate), triose phosphate, NADH, ATP, pyruvate
What does glycolysis require?
ATP, ADP and Pi, NAD
How are pyruvate and NADH moved into the matrix of the mitochondria?
By active transport
What are the stages of glycolysis?
- Glucose to phosphorylated glucose using 2 ATP molecules
- Two molecules of triose phosphate made
- Triose phosphate oxidised by NAD and ADP and Pi to produce a molecule of pyruvate each
- ATP and NADH produced
What are the stages of the Krebs Cycle?
- ACoA is combined with a 4C compound to form a 6C compound
- This is then changed into a 5C compound through the loss of a CO₂ molecule and the use of NAD
- The 5C compound is then changed to a 4C compound through the loss of another CO₂ molecule. Two more NAD molecules are reduced, as well as an FAD molecule.
- One molecule of ATP is also produced
What are the stages of the link reaction?
- Pyruvate is oxidised to form Acetyl Coenzyme A (ACoA)
- A molecule of CO₂ is produced, as well as NADH
- Coenzyme A is added to make ACoA, which is a 2C compound
What are the stages of oxidative phosphorylation?
- NADH and FADH molecules from Krebs Cycle release protons and electrons
- Electrons transported along the Electron Transport Chain which releases energy
- Energy used to actively transport protons from the matrix into the intermembranal space through carrier proteins
- Electrochemical gradient created, so protons move by facilitated diffusion down gradient and through ATP synthase
- ATP synthase phosphorylates ADP and Pi to create ATP
- Oxygen is final electron acceptor, so accepts them at end of ETC
- It also combines with the protons to form H₂O
Where does anaerobic respiration take place?
Cytoplasm
What does anaerobic respiration produce in animal cells?
Lactate
What does anaerobic respiration produce in plant and bacteria cells?
Ethanol and CO₂
How does glycolysis continue to regenerate NAD?
When NADH is produced in glycolysis, during anaerobic respiration the protons and electrons can be given to the pyruvate to convert it to either lactate, or ethanol and CO₂. ATP is also continually produced this way.
