10 (d) Photosynthesis
The process by which a cell captures energy in sunlight and uses it to make food is called photosynthesis (foh toh sin thuh sis). The term photosynthesis comes from the Greek words photo, which means “light,” and synthesis, which means “putting together.”
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis. Grass obtains energy directly from sunlight, because it makes its own food during photosynthesis. When the zebra eats the grass, it gets energy that has been stored in the grass. Similarly, the lion obtains energy stored in the zebra. The zebra and lion both obtain the sun’s energy indirectly, from the energy that the grass obtained through photosynthesis.
Plants manufacture their own food through the process of photosynthesis. During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars. The first stage of photosynthesis involves capturing the energy in sunlight. The cell uses the captured energy to produce sugars. The cell needs two raw materials for this stage: water (H2O) and carbon dioxide (CO2). In plants, the roots absorb water from the soil. The water then moves up through the plant’s stem to the leaves. Carbon dioxide is one of the gases in the air. Carbon dioxide enters the plant through small openings on the undersides of the leaves. Once in the leaves, the water and carbon dioxide move into the chloroplasts.
The water and carbon dioxide undergo a complex series of chemical reactions. These reactions produce chemicals as products. One product is a sugar that has six carbon atoms. Six-carbon sugars have the chemical formula C6H12O6. Recall that sugars are a type of carbohydrate. Cells can use the energy in the sugar to carry out important cell functions.
The other product of photosynthesis is oxygen (O2). Almost all the oxygen in Earth’s atmosphere was produced by living things through the process of photosynthesis.
Nearly all living things obtain energy either directly or indirectly from the energy of sunlight captured during photosynthesis. Grass obtains energy directly from sunlight, because it makes its own food during photosynthesis. When the zebra eats the grass, it gets energy that has been stored in the grass. Similarly, the lion obtains energy stored in the zebra. The zebra and lion both obtain the sun’s energy indirectly, from the energy that the grass obtained through photosynthesis.
Plants manufacture their own food through the process of photosynthesis. During photosynthesis, plants and some other organisms use energy from the sun to convert carbon dioxide and water into oxygen and sugars. The first stage of photosynthesis involves capturing the energy in sunlight. The cell uses the captured energy to produce sugars. The cell needs two raw materials for this stage: water (H2O) and carbon dioxide (CO2). In plants, the roots absorb water from the soil. The water then moves up through the plant’s stem to the leaves. Carbon dioxide is one of the gases in the air. Carbon dioxide enters the plant through small openings on the undersides of the leaves. Once in the leaves, the water and carbon dioxide move into the chloroplasts.
The water and carbon dioxide undergo a complex series of chemical reactions. These reactions produce chemicals as products. One product is a sugar that has six carbon atoms. Six-carbon sugars have the chemical formula C6H12O6. Recall that sugars are a type of carbohydrate. Cells can use the energy in the sugar to carry out important cell functions.
The other product of photosynthesis is oxygen (O2). Almost all the oxygen in Earth’s atmosphere was produced by living things through the process of photosynthesis.