Maslov Dmitry No chemical process is more important to life on Earth than photosynthesis —the series of chemical reactions that allow plants to harvest sunlight and create carbohydrate molecules. Without photosynthesis, not only would there be no plants, the planet could not sustain life of any kind.
It has been estimated that billion tons of sugar sugar is a simple carbohydrate is made every year by green plants, marine algae, and certain kinds of bacteria. That is equal to the weight of million blue whales give or take a few hundred thousand!
The certain kind of bacteria is more properly called cyanobacteria. A Very Important Molecule Gasoline is fuel for cars. Carbohydrates, made only by plants during photosynthesis, are the fuel for all living things.
A very important carbohydrate is a sugar yes sugar is a carbohydrate called glucose. Glucose is the basic fuel and basic building material for much of life.
The picture below shows how glucose molecules are constructed. It's not as complicated as it looks. Look at it for awhile.
Count each type of atom. How many carbon atoms are there?
Scroll to the picture below of a Glucose Molecule Fuel and Building Blocks Glucose and other sugars all made during photosynthesis are the fuels that power all living things. While you are sitting there reading this, every cell in your body is busy "burning" sugar to provide the energy for you to think and breathe and digest food and pump blood and stay warm and say things like, "Wow, this is interesting!
For example, the walls of plant cells are made in large part of starch and cellulose. They are the structural material of leaves, stems, limbs, and trunks. Starch and cellulose are made of long chains of glucose molecules attached together.
Sugar molecules are also used as starting material for molecules like the amino acids and nucleotides from which larger more complicated molecules used by our bodies are formed. In the picture above, the little black lines between atoms represent the chemical bonds which you can think of as sort of like hand holding between the atoms.
It's how they hold on to each other. It's not really how they look. There aren't really little black lines between the atoms. For that matter, there isn't really a little glowing yellow star of energy in the center of each molecule. The stored energy is really in the chemical bonds.
When those bonds are broken the stored energy is released. Many carbohydrate molecules have twice as many hydrogen atoms as carbon and oxygen. Carbon atoms have a quirk. They always want to hold on to four other atoms or groups of atoms molecules. Go ahead, count them in the picture above.
This ability to hold on to four other atoms, allows for a tremendous diversity and variety of molecules based on the carbon atom attached to other atoms. Pretty much all living things are built around carbon based molecules. The study of the chemistry and molecules of living things is basically the study of the chemistry of carbon.
Living compounds are based on carbon atoms attaching to themselves and to other atoms. That's why in futuristic science fiction movies the evil machines and computers are always trying to eliminate the "carbon-based" life forms that are infesting the world.
Back to the Top of the Page.Stages of Photosynthesis | Back to Top. Photosynthesis is a two stage process. The first process is the Light Dependent Process (Light Reactions), requires the direct energy of light to make energy carrier molecules that are used in the second process.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that can later be released to fuel the organisms' activities. This chemical energy is stored in carbohydrate molecules, such as sugars, which are synthesized from carbon dioxide and water – hence the name photosynthesis, from the Greek φῶς, phōs, "light", and σύνθεσις.
No chemical process is more important to life on Earth than photosynthesis —the series of chemical reactions that allow plants to harvest sunlight and create carbohydrate molecules. Without photosynthesis, not only would there be no plants, the planet could not sustain life of any kind.
Watch video · We can break down photosynthesis-- and we'll delve deeper into future videos, but I want to get you the overview first-- into two stages. We can call one the light reactions. Or sometimes they are called the light-dependent reactions, and that actually would probably be a better way to write it.
Three of the Four Stages in Photosynthesis Occur Only during Illumination. It is convenient to divide the photosynthetic process in plants into four stages, each occurring in a defined area of the chloroplast: (1) absorption of light, (2).
Photosynthesis takes place within cells on plants' leaves. Throughout the day, photons hit the plants leaves. Within these halls of antennae, incident photons generate electrons via the photoelectric effect.