Respiration
No description yet. This curated deck is ready for daily study.
Card preview (19)
aerobic respiration
requires oxygen and produces carbon dioxide, water and much ATP
anaerobic respiration
takes place in the absence of oxygen and produces lactate or ethanol and carbon dioxide but only little ATP
What are the four stages of of aerobic respiration
-glycolysis -link reaction -krebs cycle -oxidative phosphorylation
Describe the process of glycolysis
-Phosphorylation of glucose using ATP - Oxidation of TP to pyruvate -Net gain of ATP -NAD reduced
Malonate inhibits a reaction in the Krebs cycle. Explain why malonate would decrease the uptake of oxygen in a respiring cell.
-Less reduced NAD -oxygen is the final electron acceptor
Explain why converting pyruvate to lactate allows the continued production of ATP by anaerobic respiration.
-Regenerates NAD -So glycolysis can continue
Where does glycolysis occur
Cytoplasm
Process of the link reaction
-Pyruvate from glycolysis is oxidised to acetate - Hydrogen lost by pyruvate is picked up by NAD and reduced to NADH and 1C is produced -Acetate combines with coenzyme A to produce AcetylCOA
Process of the Krebs cycle
• AcetylCOA from the link reaction combines with a 4C molecule to make a 6C molecule -In a series of redox reactions the 6C molecule becomes a 4C losing 2 carbon dioxide and hydrogen -ATP is produced -The hydrogen removed during the reactions reduces FAD and NAD
why are NAD and FAD important
they have the potential to provide energy to produce ATP molecules by oxidative phosphorylation
Where does the link and krebs cycle occur
Matrix of the mitochondria
what is a coenzyme
molecules which transfer chemical groups in reactions and are continually recycled
What is an example of a coenzyme
-NAD -FAD -NADP
What is the significance of the kreb cycle
-it breaks down macromolecules into smaller ones (pyruvate to carbon dioxide -produces hydrogen that are carried by NAD to the electron transfer chain and provides energy for oxidative phosphorylation
Process of oxidative phosphorylation
-NADH is oxidised and the e- reduce the first electron carrier in the electron transfer chain. -Series of redox reactions as they transfer between electron carriers and release energy -FADH donates electron to the chain - The energy from the e- allows the active transport of H+ from the matrix through proton pumps to the inner membrane space -Maintains a chemiosmotic gradient with a high conc of H+ in the intermembrane space and low conc in the matrix -H+ diffuse by facilitated diffusion through ATP synthase making ATP -Oxygen is the final electron acceptor, along with H+ to form water.
Where does oxidative phosphorylation occur
inner membrane/ cristae of the mitochondria
Explain how energy is released by respiration in the absence of oxygen
In the absence of oxygen FAD and NAD will be reduced but unable transfer their hydrogen atoms in the electron transfer chain. This results in NAD and FAD being unavailable for further reduction during krebs cycle. Only glycolysis can occur, this happens due to hydrogen being removed from reduced NAD by the pyruvate that has been produced.
Explain how ethanol is produced by anaerobic respiration
Some bacteria, fungi and plants produce ethanol during anaerobic respiration (fermentation). The pyruvate from glycolysis loses a carbon dioxide molecule and accepts hydrogen from reduced NAD to form ethanol.
Explain how lactate if produced by anaerobic respiration
Animals in short supply of oxygen produce lactate (also known as lactic acid). Pyruvate from glycolysis removes hydrogen from reduced NAD to form lactate.