Answer to Question #112019 in Cell Biology for Suresh singh

Question

Difference between Mitochondria and Chloroplast

Answer 1

Mitochondria and chloroplasts are the organelles, which convert energy to forms that cells

can use for work. Mitochondria are the sites of cellular respiration, the metabolic process, which uses oxygen to generate ATP by extracting energy from organic compounds. Chloroplasts are the sites of photosynthesis. This process in chloroplasts converts solar energy to chemical energy and uses it to synthesize organic compounds such as sugars from carbon dioxide and water. They have a lot of similar features, but the main difference is in the set of enzymes necessary for the reactions occurring in these organelles.

1.Chloroplast membranes contain chlorophyll and its associated proteins and are the sites of photosynthesis. In addition to their inner and outer envelope membranes, chloroplasts possess a third system of membranes called thylakoids.The ATP synthases of the chloroplast are located on the thylakoid membranes .

2.The chloroplast genome is smaller than the mitochondrial genome.

3.Two photochemical complexes, known as photosystems I and II (PSI and PSII), operate in series to carry out the energy storage reactions of photosynthesis.The two photosystems are linked by an electron transport chain. These systems are used for ATP synthesis, but there is a second step( carbon reactions of photosynthesis) , which localizes in the stroma ,soluble phase of chloroplasts. Cyclic reactions provide fixation and reduction of CO2. They are also known as the Calvin Cycle or reductive pentose phosphate cycle, and needs acceptor of CO2-ribulose-1,5-bisphosphate and different enzymes.

4. The inner membrane of a mitochondrion contains some phospholipids that are unique to the organelle-cardiolipin. The ATP synthases of the mitochondria are located on the inner membrane. The inner membrane also have special enzymes, which provide citric acid cycle reactions.

5.Chloroplast uses NADPH instead of mitochondrial NADH and FADH2.