How can glucose be formed?
How can glucose be formed?
what are are the conditions for glucose to be formed
¿que tipos de azúcar existen?
Energy from the plants is formed during carbon fixation.
What is respiration?
Photosynthesis is a complex process that involves the plant using energy from sunlight to combine carbon dioxide gas with water to make sugar. The reaction can be expressed in words as follows:
water + carbon dioxide --> sugar + oxygen
The sugar is typically in the form of glucose, but it could be other kinds of sugar, or indeed sugar alcohols.
The sugars that the plants produce from carbon dioxide and water are a concentrated form of energy. Energy cannot be created - it can only be converted from one form to another. The energy in sugars comes from the energy in visible light - sunlight. The plant uses the sugars it produces to form other compounds within its tissues and it is these compounds that can be used as biofuels.
Visible light is composed of a spectrum of colours, as in a rainbow. It is one form of electromagnetic radiation, which is defined as energy in the form of waves that have both electrical and magnetic properties. The electromagnetic spectrum is defined as a series of different forms of radiation which have different wavelengths.
The photosynthetic pigments in plants absorb best in certain areas of the electromagnetic spectrum - generally speaking those areas corresponding to visible light and, in particular, the blue and red portions of the visible spectrum.
The absorption of light takes place within specialised membranes within the chloroplasts called the thylakoid membranes. In order to pack more closely together the thylakoid membranes can form flattened stacks called grana (singular granum).
The reactions of photosynthesis take place in two phases: the absorption of light takes place in the first phase and the second phase occurs in the watery fluid, the stroma, which surrounds the thylakoid membranes. The chloroplast itself is bounded by two membranes that are situated very close together and called the chloroplast envelope.
Photosynthesis consists of two main stages: the so-called ‘light reactions’ and the ‘light independent or dark reactions’.
In the series of very complicated light reactions the energy from sunlight is used to produce two main compounds ATP (which stands for adenosine triphosphate) and NADP.2H (a complicated chemical called nicotinamide adenine dinucleotide).
ATP and NADP.2H are used to convert carbon dioxide, via a complex series of reactions, to sugars - the end point of photosynthesis. These reactions are the dark reactions which take place in the stroma.
The carbon dioxide gas moves from a stoma to a chloroplast. There, in a series of reactions that use ATP and NADP.2H, the carbon dioxide binds to a protein called Rubisco (ribulose 1, 5 bisphosphate carboxylase oxygenase) and eventually sugar is produced.
Different plants will produce different kinds of sugar but most commonly it is glucose. The sugar can then be moved throughout the plant to wherever it is required.
Photosynthesis is such a widespread process and Rubisco is so central to it, the amount of Rubisco present in plants worldwide has been estimated to be 25% of all protein globally. You shouldn’t have any doubts now as to the importance of the photosynthetic process!