Tag: fermentation

Questions Related to fermentation

Sometimes, higher plants and animals too perform anaerobic respiration.

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. True

  2. False

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Correct Option: A
Explanation:

(i). Respiration is an energy yielding process and takes place by the oxidation of foodstuffs.
(ii) Higher plants and animals require oxygen in order to respire aerobically.
(iii) However, in conditions where oxygen is depleted, these organisms perform anaerobic respiration to obtain energy.

(iv). Glucose is incompletely oxidized and a comparatively lesser amount of energy is obtained through anaerobic respiration. The anaerobic respiration mainly takes place during strenuous exercise when there is shortage of oxygen, which leads to production of lactic acid in muscles.

In alcohol fermentation

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. Triose phosphate is the electron donor while acetaldehyde is the electron acceptor

  2. Triose phosphate is the electron donor while pyruvic acid is the electron acceptor

  3. There is no electron donor

  4. Oxygen is the electron acceptor

Show answer
Correct Option: A
Explanation:

In alcohol fermentation, the pyruvic acid (triose phosphate) produced through glycolysis is subjected to the oxidative decarboxylation, wherein the pyruvic acid is converted to the acetaldehyde. The acetaldehyde accepts the electrons and is reduced to form the alcohol or ethanol. There is no external electron acceptor involved as in case of aerobic respiration

So, the correct answer is 'triose phosphate is the electron donor while the acetaldehyde is the electron acceptor'

In anaerobic respiration of yeast

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. ${ O } _{ 2 }$ is given out

  2. ${ CO } _{ 2 }$ is given out

  3. ${ CO } _{ 2 }$ is taken in

  4. ${ O } _{ 2 }$ is taken in

Show answer
Correct Option: B
Explanation:

Yeast respires anaerobically (in the absence of oxygen) . The process is known as fermentation. Glucose is the respiratory substrate.

The glucose is converted to pyruvate by the process of glycolysis. This process is independent of oxygen. If oxygen is absent, the pyruvate is broken by yeast into ethanol releasing carbon dioxide along with the production of 2 ATP.
So, the correct answer is 'CO$ _2$ is given out'.

During fermentation what does not occurs ___________________.

biology life processes in living organisms- part 1 fermentation cell respiration living organisms and energy production

  1. Oxidation of glucose into pyruvate

  2. Substrate level phosphorylation

  3. Oxidation of $NADH _2$

  4. Oxidative phosphorylation.

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Correct Option: D
Explanation:

Answer is option D i.e. "Oxidative phosphorylation"
Fermentation occurs only when there is no oxidative phosphorylation to maintain the production of ATP by glycolysis. During fermentation, pyruvate is metabolized to various compounds such as lactic acid, ethanol and carbon dioxide or other acids. Also, fermentation reactions occur in the cytoplasm while oxidative phosphorylation occurs in mitochondria.

Select the number of incorrect statements for the process of fermentation.
A . It involves only partial breakdown of glucose.
B $NADH _2$ is oxidized to NAD by reduction of organic compound.
C. No ATP are produced during fermentation as it is extracellular process in some microbes.
D. There is no ETS and Kreb's cycle.
E. Maximum concentration of alcohol in alcohol in alcoholic brevarage is 100 %.

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. 2

  2. 3

  3. 4

  4. 5

Show answer
Correct Option: A
Explanation:
  • Fermentation can be defined as the partial breakdown of glucose to produce ethyl alcohol and carbon dioxide.
  • It releases energy in form of  ATP molecules.
  • 2 ATP molecules are produced per glucose.
  • 2NADH molecules provide energy which converts pyruvate into lactic acid.
  • The maximum concentration of alcohol in alcoholic beverages is 15%-16%.
  • Option C and E are incorrect statements.
  • So, the correct answer is'2'.

Fermentation is carried out by

biology life processes in living organisms- part 1 fermentation cell respiration living organisms and energy production

  1. All bacteria

  2. All fungi

  3. Some bacteria and some fungi

  4. All micro-organisms

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Correct Option: C
Explanation:

Fermentation is incomplete oxidation of food substances into alcohol and lactic acid with the small amount of energy being released. Both lactic acid and ethanol fermentation do not produce oxygen. It is carried out by anaerobic bacteria and fungi. Aerobic bacteria and fungi carry out aerobic respiration. Thus, the correct answer is option C.  

Which of the following enzymes is not required during fermentation process?

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. Lactic acid dehydrogenase

  2. Pyruvate dehydrogenase

  3. Pyruvate decarboxylase

  4. Alcohol dehydrogenase

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Correct Option: A

Final electron acceptor in fermentation 

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. $O _2$

  2. organic molecule

  3. $H _2O$

  4. always pyruvic acid

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Correct Option: A

Which of following is final $e^-$ acceptor in lactic acid fermentation :-

biology respiration in plants fermentation cell respiration living organisms and energy production

  1. Pyruvic acid

  2. Ethanol

  3. Acetaldehyde

  4. $O _2$

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Correct Option: A
Explanation:

Under normal aerobic conditions, the final electron acceptor at the end of the electron transport chain is oxygen. However, fermentation occurs when there is no oxygen available. Therefore, something else must act as the final electron acceptor. In lactic acid fermentation, NADH is the electron carrier that ultimately carries them to pyruvate. Pyruvate is reduced to lactic acid, and thus, acted as the final electron acceptor.

So, the correct option is 'Pyruvic acid'.

The product of fermentation is

biology life processes in living organisms- part 1 fermentation cell respiration living organisms and energy production

  1. Ethanol and lactic acid

  2. Acetic acid and lactic acid

  3. Ethanol and acetic acid

  4. All of the above

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Correct Option: D
Explanation:

Fermentation is a metabolic process in which an organism converts a carbohydrate, such as starch or a sugar, into an alcohol or an acid. For example, yeast perform fermentation to obtain energy by converting sugar into alcohol. Lactic acid fermentation takes place in muscles during heavy exercise producing lactic acid. The products of fermentation are acetic acid, lactic acid, ethanol etc.

Thus, the correct answer is option D.