Article-21

Article-2⃣1⃣

*Self-Practice*

Std.10th -Science Part 2

Topic 2: *Life Process in Living Organisms Part-1*

 ★★★★★★★★★

*Today's exercise*:

Write a detailed answer to the following question.

1) Why ATP is called as energy currency?

★★★★★★★★★

*Electron Transfer Chain reaction:*

[ETC reaction]

1] Most living cells produce energy from nutrients through cellular respiration that involves the taking up of oxygen to release energy. The electron transport chain or ETC is the third and final stage of this process, the other two being glycolysis and the citric acid cycle. 

2] The ETC reactions take place on and across the inner membrane of the mitochondria.

3] The third phase ETC reaction is accelerated with the help of NADH2 and FADH2 co-enzymes obtained from the second phase "citric acid cycle."

4] In ETC reaction NADH2 and FADH2  co-enzymes give electrons and oxygen accept the same electrons. This process of electron exchange takes place simultaneously, hence this reaction is called as "redox reaction".  In this series of continuous redox reactions, the ADP molecule is converted into ATP by adding a third phosphate group.

5] After accepting electrons from NADH2 and FADH2, the original co-enzymes NAD and FAD are sent back to the TCA cycle / Kreb's cycle.

6] In ETC reaction, 3 ATP molecules are obtained from each NADH2 and 2 ATP molecules are obtained from each FADH2 molecule. 

7] Each of the three cellular respiration phases incorporates important cell processes, but the ETC produces by far the most ATP. Since energy production is one of the key functions of cell respiration, so ETC is the most important phase from that point of view.

8] ETC phase produces up to 34 molecules of ATP from the products of one glucose molecule, the citric acid cycle produces two, and glycolysis produces four ATP molecules but uses up two of them.

9] Most of the oxygen inhelled in cell respiration is used in the ETC reaction.

10] The cellular respiration reaction equation is shown as follows.

C6H12O6 + 6O2 -----> 6CO2 + 6H2O + 38 ATP

■■■

 *Do you know this?*

◆ In ATP, meaning of 'T' is tri. tri= three; It means ATP contains three phosphate molecules.

 

◆ When one of the phosphate molecule breaks down, energy releases from ATP and ATP converts into ADP. 

◆ In ADP, meaning of 'D' is di = two. It having only two phosphate group molecules.In ETC reaction, this ADP molecule aquirs again one phosphate group and  become an energetic ATP molecule. 

■■■

...✍

*Shrishail Mathapati,* Kolhapur 

💢Ⓜ💢Ⓜ💢Ⓜ