Cellular Respiration and Enzymes

Glycolysis is the foremost step in the process of cellular respiration which breakdown glucose molecule to extract energy. It is the part of the metabolism of nearly all the cells and organisms as it is the basic process, it does not require oxygen hence it is anaerobic. it occurs in the cytoplasm of both prokaryotes as well as eukaryotes.

• For the glycolysis to start the glucose molecule is firstly to be converted to Glucose 6 phophaste after that only will the reaction proceed for which ATP is required which is converted to ADP after the conversion.
• So when the amount of the ATP in the cell is reduced and the amount of ADP is increased the process is to be started to provide the cell with the required ATP.
• So the receptors of the cells or the gene that regulate the process of glycolysis are somewhat stimulated by the presence of increased amount of ADP as there are other factors also which control the process of glycolysis such as the amount of ATP, Pyruvic acid etc.
• Therefore it can be said that the ADP is one of the stimulating factors for the Glycolysis process.
• Therefore the correct answer is option 'stimulated by ADP'.

• First part for both type of respiration aerobic and anaerobic is glycolysis where the sugar is broken down to pyruvic acid.
• Glycolysis takes place in the cytoplasm of the cells and does not require for the presnece of any organelles.
• So both kind of organisms are able to perform glycolysis whether they perform aerobic or anaerobic reactions.
• Thus it can be said that in both kind of respiration glycolysis is a common process which provides substrate for further reactions in both kind of respiration. Pyruvic acid which converts to acetyl coA and takes part in kerb cycle while pyruvic acid converts to lactic acid or alcohol in fermentation reaction.
• Therefore the correct answer is option 'Glycolysis'.
  

• The whole process of glycolysis takes place in the cytoplasm it does not require any membrane bound organelles to perform the reaction.
• GLycolysis is the main process to obtain energy in the prokaryotic organisms where there are no membrane bound organelles present and glycolysis is the only source of obatining energy.
• Therefore the enzymes and substrate required for the process of glycolysis are present in the cytoplasm and the whole reaction takes place in the cytoplasm.
• Therefore the answer 'cytoplasm' is correct.
  

• As the reaction of glycolysis takes place in the cytoplasm of cell where it can proceed in the absence of oxygen molecule. 
• It does not require the presence of oxygen of to proceed further.
• It will produce 4 ATP molecules and use 2 molecules of ATP, which gives the cell the net gain of 2 ATP at the end of the glycolysis process.
• Presence of oxygen or absence of oxygen does not hinder the process of glycolysis and prodution of ATP by glycolysis.
• Therefore the answere option 'glycolysis produces equal numbers of ATP molecules regardless of the presence or absence of oxygen' is true.
  

The initial processes for energy generation by prokaryotes included anaerobic processes such as Glycolysis and Fermentation. The latter happening of endosymbiosis was the major revolution in bringing up aerobic respiration with the advent of mitochondria within the cells.

• Glycolysis is the pathway were one molecule of glucose is broken down to 2 molecules of pyruvate by the phosphorylation and dephosphorylation reactions.
• 2 molecules of ATP are used in phosphorylation reaction of glycolysis. First while conversion of glucose to glucose-6-phosphate and the second one during conversion of fructose to fructose1,6-biphosphate.
• While 4 ATP molecules are produced in the dephosphorylation reaction. 2 ATP are produced while conversion of  1,3 bisphosphoglyceric acid to 3-phosphoglyceric acid and another 2 ATP during conversion of phosphophenolepyruvate to pyruvic acid.
• So the net gain of ATP at the end of one glycolysis reaction is 2. SO glycolysis is not a efficient pathway for the production of ATP in animal cells, in turn it is a part of the chain of reaction which take place before aerobic or anaerobic respiration in animal cells.
• Glycolysis provided the reaction of aerobic and anaerobic respiration with the substrates to carry the reaction further and produce ATPs in mitochondria where the prominent reactions for production of energy in animal cell takes place.
• Glycolysis takes place in the cytoplasm of the cell and the product of the glycolysis is transported to the mitochondria.
• Therefore Glycolysis is not the most efficient pathway for ATP production. So the sentence above is FALSE and therefore the option 'False' is correct.
  

• NADH is formed in the glycolysis after the reaction of conversion Glyceradehyde 3 phosphate to 3 phosphoglyeric acid when electrons re released and are accepted by the NAD.
• ATP is formed  while conversion of 1,3 bisphosphoglyceric acid to phospoglyceric acid and also while conversion of phosphophenol to pyruvic acid.
• And pyruvate is the end product of the glycolysis.
• FADH is the product which is formed  during the the kerb cycle while formation of succunic acid to malic acid.
• Thereofte the correct answer is '$FADH _2$'

After fats are digested into fatty acids and glycerol, the following products can take place in cellular respiration.

In the energy conserving phase of glycolysis, the conversion of BPGA to PGA is catalyzed by phosphoglycerate kinase. The phosphate on carbon 1 is transferred to a molecule of ADP, yielding ATP and 3-phosphoglycerate. This type of ATP synthesis, traditionally referred to as substrate-level phosphorylation, involves the direct transfer of a phosphate group from a substrate molecule to ADP, to form ATP.
$1,3-bisphosphoglycerate+ADP\overset{Phosphoglycerate kinase}{\underset{{Mg}^{2+}}{\rightleftharpoons}}3-phosphoglycerate+ATP$

Glycolysis produces 2 ATP, 2 NADH,2 pyruvate molecules. It is the aerobic catabolic breakdown of glucose, which produces energy of 68KJ in form of ATP, NADH, and pyruvate, which itself enters a citric acid cycle to produce more energy.

Glycolysis, part of cellular respiration, is a series of reactions that constitute the first phase of most carbohydrate catabolism. Catabolism means the breaking down of larger molecules into smaller ones. The word glycolysis is derived from two Greek words and means the breakdown of something sweet. Glycolysis breaks down glucose and forms pyruvate with the production of two molecules of ATP. The pyruvate end product of glycolysis can be used in either anaerobic respiration if no oxygen is available or in aerobic respiration via the TCA cycle which yields much more usable energy for the cell.  When oxygen is present, NADH can pass its electrons into the electron transport chain, regenerating NAD$^+$ for use in glycolysis. When oxygen is absent, cells may use other, simpler pathways to regenerate NAD$^+$ these pathways, NADH donates its electrons to an acceptor molecule in a reaction that doesn’t make ATP but does regenerate NAD$^+$ so glycolysis can continue. This process is called fermentation.