Cellular Respiration Flashcards
What is ATP?
Main molecule in cells that transfers energy, providing energy for all body cells that can be used immediately.
Energy currency of cell.
How is ATP used to supply energy?
Unstable phosphate tail - hydrolysed, molecule becomes more stable. The ATP bond energy is taken by cells during coupled reactions. Phosphate groups are transferred to other compounds.
How can nutrients be processed for energy release?
- digestion in GI tract
- in tissues and cells, nutrients built into glycogen, lipids, proteins
- in mitochondria, catabolic activity requires oxygen
Define cellular respiration.
Metabolic process in animals where organic substances are broken down with released of energy, which is incorporated into ATP and used for other metabolic processes.
Define oxidation.
Gain of oxygen/loss of hydrogen.
What redox reactions occur in respiration?
Often in couples. Ox of foods transfers energy, then to ADP to form ATP. For ox pathways, coenzymes are NAD+ and FAD.
What occurs during glycolysis?
- Phosphorylation of glucose by hexokinase (traps glucose in cell). PFK reaction = rate limiting step.
- Glucose split into GAP and DHAP, catalysed by adolase.
- Generates ATP, NADH and pyruvate.
How are metabolic pathways regulated?
- irreversible
- rate limiting
- altered by energy status or conc of substrate/product
What is pyruvate oxidation?
Process of converting pyruvate to acetyl coA, catalysed by pyruvate dehydrogenase complex. This process is oxidative decarboxylation and requires TPP.
What is fatty acid oxidation?
Beta oxidation occurs to fatty acid chains, which are broken down to 2C fragments of acetic acid. FAD and NAD+ reduced.
Acetic acid combines with coA, forming acetyl coA.
What are the 4 reactions required to break down a saturated acetyl-coA?
Oxidation by FAD
Hydration
Oxidation by NAD+
Thiolysis by coA
How is a fatty acid oxidised for form acetyl CoA?
Activated FA oxidised so double bond forms. Double bond hydrated so hydroxyl group present. Alcohol oxidised to ketone. FA cleaved by coA to produce acetyl coA.
What is the function of oxidative phosphorylation?
Helps convert energy to ATP, on the inner mitochondrial membrane. The final electron acceptor in oxygen.
What are features of the electron transport chain?
Some multi protein complexes are flavins, others contain Fe2+ or 3+.
More turns of the cycle, more ATP produced.
More H+ flowing through ATP synthase, more ATP produced.
