Name: Photosynthetic Pigments
Uploaded: 2019-07-19
Duration: 10 min 37 s
Description: There are six photosynthetic pigments in plants of which chlorophyll is of paramount importance. They absorb light of a certain wavelength for photosynthesis...

Question

In both mitochondria and chloroplasts, an energetic electron passes along a chain of carriers and the energy released is used to synthesise ATP by chemiosmosis. Suggest why the process occurring in mitochondria is known as oxidative phosphorylation, whereas in chloroplast it is photophosphorylation.

Accepted Answer

According to the chemiosmotic hypothesis, ATP synthesis is related to the formation of a proton gradient. ATP is formed from ADP by phosphorylation that takes place both in chloroplast and mitochondria. In mitochondria, the formation of ATP is called oxidative phosphorylation. In this process, the energetic electrons pass from the NADH2 and FADH2 along a chain of carrier proteins and reach oxygen that is the final electron acceptor in the electron transport system. Thus, oxygen accepts hydrogen ions and is reduced to form water with these electrons. This process is called oxidative phosphorylation.
In chloroplast, the electrons are emitted from chlorophyll molecules in the presence of light. The electrons are passed through different carrier proteins create a proton gradient that leads to the synthesis of ATP. This process is called photophosphorylation because this process takes place in the presence of light.

Mary Jones, Richard Fosbery, Dennis Taylor and, Jennifer Gregory Solutions for Chapter: Photosynthesis, Exercise 5: Questions

Mary Jones Biology Solutions for Exercise - Mary Jones, Richard Fosbery, Dennis Taylor and, Jennifer Gregory Solutions for Chapter: Photosynthesis, Exercise 5: Questions

Questions from Mary Jones, Richard Fosbery, Dennis Taylor and, Jennifer Gregory Solutions for Chapter: Photosynthesis, Exercise 5: Questions with Hints & Solutions

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