0
fermentation
Wiki User
∙ 12y ago
Wiki User
∙ 13y agoFermentation.
Add your answer:
Earn +20 pts
Why are lactate and ethanol formed under anaerobic conditions?
Short Answer: To regenerate NAD+ for the continued function of glycolysis.Detailed Answer: As NADH is formed in glycolysis (2 NADH per glucose), NAD+ must be regenerated to allow continued glycolytic flux (and consequent production of ATP). In the presence of adequate oxygen (i.e. under aerobic conditions), this regeneration takes place predominantly in the mitochondria. Under anaerobic conditions, however, the only way to regenerate NAD+ is through lactate fermentation (e.g. mammals) or ethanol fermentation (e.g. yeast).
Can a human survive from only using anaerobic respiration?
Because, the link reaction and the Krebs cycle in respiration can only occur when there is oxygen present. When there is no oxygen available (i.e under anaerobic conditions), the electron transfer chain (etc) can not pass on its electron (as oxygen is the final electron acceptor in the etc). So, the electrons build up in the etc, therefore, electrons from the hydrogen from reduced NAD can no longer be accepted by the cytochromes in the etc. Because of this, no reduced NAD can be converted into oxidised NAD, and hence there is nothing to accept the hydrogens produced in the link reaction and Krebs cycle. Hence the etc and Krebs cycle grind to a halt. Glycloysis, however, can still occur in anaerobic conditions. However, as there is no NAD to accept the hydrogens produced in glycolysis ( due to the blocked etc), the pyruvate formed in glycolysis acts as a hydrogen acceptor. This forms lactic acid, which builds up in the the muscle tissue (and gives you 'stitch') Anaerobic respiration produces a fraction of the ATP that wound be synthesised in aerobic conditions (about 10% i think)
Where does aerobic glycolysis occur?
Anaerobic respiration takes place in the Cytoplasma.
How do you recycle NADH to NAD?
How do you recycle NADH into NAD?
When NAD reacts with hydrogen and gains two electrons NAD?
NAD+ is reduced. It becomes NADH.
What is the recycling of NAD plus under anaerobic conditions?
Fermintation
Does the recycling of ATP ensure the continuation of glycolysis under anaerobic conditions?
NAD+2
Why the Krebs cycle does not run under anaerobic conditions?
Because NAD+ level will decrease if oxygen is not present to regenerate NADH to NAD + Because NAD+ level will decrease if oxygen is not present to regenerate NADH to NAD +
Why are lactate and ethanol formed under anaerobic conditions?
Short Answer: To regenerate NAD+ for the continued function of glycolysis.Detailed Answer: As NADH is formed in glycolysis (2 NADH per glucose), NAD+ must be regenerated to allow continued glycolytic flux (and consequent production of ATP). In the presence of adequate oxygen (i.e. under aerobic conditions), this regeneration takes place predominantly in the mitochondria. Under anaerobic conditions, however, the only way to regenerate NAD+ is through lactate fermentation (e.g. mammals) or ethanol fermentation (e.g. yeast).
Can a human survive from only using anaerobic respiration?
Because, the link reaction and the Krebs cycle in respiration can only occur when there is oxygen present. When there is no oxygen available (i.e under anaerobic conditions), the electron transfer chain (etc) can not pass on its electron (as oxygen is the final electron acceptor in the etc). So, the electrons build up in the etc, therefore, electrons from the hydrogen from reduced NAD can no longer be accepted by the cytochromes in the etc. Because of this, no reduced NAD can be converted into oxidised NAD, and hence there is nothing to accept the hydrogens produced in the link reaction and Krebs cycle. Hence the etc and Krebs cycle grind to a halt. Glycloysis, however, can still occur in anaerobic conditions. However, as there is no NAD to accept the hydrogens produced in glycolysis ( due to the blocked etc), the pyruvate formed in glycolysis acts as a hydrogen acceptor. This forms lactic acid, which builds up in the the muscle tissue (and gives you 'stitch') Anaerobic respiration produces a fraction of the ATP that wound be synthesised in aerobic conditions (about 10% i think)
What terminal electron acceptors are used in anaerobic cellular respiration?
anaerobic cellular respiration has 3 different stages, and their final electron acceptors are: pyruvate oxidation- NAD+ Krebs cycle- NAD+, FAD+ electron transport chain- Oxygen
When a muscle becomes anaerobic during strenuous exercise why is it necessary to convert pyruvate to lactic acid?
to decrease the NADH and increase the NAD+
Why do fermentation conditions need to be controlled?
It is important to maintain anaerobic conditions in ethanol fermentors because ethanol is the reselt of anaerobic respiration, if oxygen is present organisms may switch to aerobic respiation resulting in less product formation. If oxygen is getting into the system has the system become infringed leading to possible containination with other microbes and so competition for nutrients?
Where does aerobic glycolysis occur?
Anaerobic respiration takes place in the Cytoplasma.
During glycolysis NAD is converted to what?
This is the Glycolysis pathway Glycolysis (the breakdown of glucose to pyruvate and lactate, occurs in the cell cytoplasm): Glucose + 2 ATP + 4 ADP + 2 NAD -> 2 Pyruvate + 2 ADP + 4 ATP + 2 NADH + energy. Oxidation of glucose is known as glycolysis. Glucose is oxidized to either lactate or pyruvate. Under aerobic conditions, the dominant product in most tissues is pyruvate and the pathway is known as aerobic glycolysis. When oxygen is depleted, as for instance during prolonged vigorous exercise, the dominant glycolytic product in many tissues is lactate and the process is known as anaerobic glycolysis. "These studies demonstrate that orderly glycolysis in the erythrocyte is regulated by the NAD-to-NADH ratio and also provide a method that makes possible the in vitro study of erythrocyte glycolysis." The conversion of pyruvate to lactate, under anaerobic conditions, provides the cell with a mechanism for the oxidation of NADH (produced during the G3PDH reaction) to NAD which occurs during the LDH catalyzed reaction. This reduction is required since NAD is a necessary substrate for G3PDH, without which glycolysis will cease. Normally, during aerobic glycolysis the electrons of cytoplasmic NADH are transferred to mitochondrial carriers of the oxidative phosphorylation pathway generating a continuous pool of cytoplasmic NAD NADH
How does the process of fermentation allow the survival of yeast?
Fermentation allows yeast to survive in an anaerobic environment without suffering the NAD+/NADH imbalance and lactate acidosis associated with regular anaerobic respiration. Excess NADH is shunted to produce ethanol from pyruvate, reducing NADH levels, replenishing NAD+ levels, and preventing the formation of acidic lactic acid.
Why does lactate accumulate in the blood during bursts of very vigorous exercise?
Lactate accumulates because of the lack of available oxygen in the muscles. In anaerobic conditions, the pyruvate produced by glycolysis is reduced to lactate via lactate dehydrogenase (while also oxidizing a single molecule of NADH to regenerate NAD+). NAD+ is a very important molecule and must readily be available in the cytoplasm in order for glycolysis to proceed.
