Mitochondria vs Chloroplast
The major difference between mitochondria and chloroplast is that the latter contains thylakoid membranes and pigment molecules, whereas the mitochondria membranes contain respiratory enzymes not found in chloroplast membranes. Chloroplasts essentially are those parts of plants cells and algae where photosynthesis takes place. Mitochondria on the other hand are located in the cytoplasm of cells which have a nucleus. These turn nutrients into molecules that fuel the cells.
Chloroplasts have the ability to use light to convert carbon, derived from carbon dioxide into sugar. Mitochondria on their part break down simple sugars into carbon dioxide and release energy. Chloroplasts are larger and have greater complexity than mitochondria, and they have several critical functions to perform, besides the generation of ATP. Apart from converting carbon dioxide to carbohydrates they synthesize amino acids, fatty acids, and the lipid contained in their own membranes.
Mitochondria are to be found in both plant and animal cells, whereas chloroplasts are found only in plant cells. The former have a structure composed of a prokaryotic cell, whereas Chlorplasts are made up of stacks of thylakoids surrounded by a fluid called stroma. According to some theories, mitochondria exist because of endocytosis of aerobic bacteria, while chloroplasts are around because of the result of endocytosis of photosynthetic bacteria.
Chloroplasts exist only in plant cells and lend the green color of most plants. Mitochondria on the other hand are found in both animal and plant cells and are engaged in the production of ATP. To use simple layman language, mitochondria in animal cells changes energy into forms that animals can use, while chloroplasts in plant cells convert sunlight into energy that plants can use. From this it follows that mitochondria in a sense are the power plant in the animal cells, because it generates energy. Chloroplasts provide the green color to the plant due to the chlorophyll present in them.
Mitochondria cells are 1 to 10 um long in length. These can change shapes, get around, and divide into two. The cell is surrounded by an envelope of two membranes. The membrane on the outside is smooth while the other one is marked by what are called cristae.
Photosynthesis happens only in plants. This is because only plants contain chloroplasts. Thus we can see that mitochondria and chloroplasts are the building blocks of life for plants and animals respectively in the sense that they provide nourishment to the organisms. The two are also representative of the dividing line between the two kingdoms of life on earth-the animal and the plant.
These two structures are markers of two philosophies of life form if one may use the use the term. One that is self sustaining, manufacturing its own food, the other that is dependent upon the former as the primary source of food, but far more complex and evolved way of life in many other aspects.
Summary:
1. Chloroplast contains thylakoid membranes and pigment molecules, whereas the mitochondria membranes contain respiratory enzymes not found in chloroplast membranes.
2. Chloroplasts are found in plants only while mitochondria are found in both plants and animals.
3. Chloroplasts help in photosynthesis.