Photosynthesis is the process which harvest the energy, which is needed for plants to produce their own food.

Contrary to popular belief, plants do not eat fertilizer (fertilizer is not plant food). Fertilizer is ingredients which go into the production of plant food and used as building blocks to build tissue, roots, etc.

Humans and animals get energy from eating. Plants do eat in a similar fashion, but first they must produce their own foods by converting carbon dioxide, water, and fertilizer nutrients into stored sources of energy (foodstuffs). This process requires energy, and the energy comes from sunlight.

Photosynthesis is a chemical reaction which takes place inside plant leaves in a pigment tissue called chorophyll. This pigment is responsible for the green plant color.

The energy is harvested by "antenna"-like structures inside the chlorophyl molecules and starts a chain reaction whereby water molecules are split, new molecules are formed, and oxygen is produced (as a waste product).

This is why plants can remove carbon dioxide form the air and replace with fresh oxygen.

Some of the new molecules which are formed are 6 carbon glucose molecules. These are - simply - sugars which, as you know, is the same as energy. For example, soccer players will eat grape sugar to recharge their energy during half time.

These sugars are used to produce new leaf tissues, flowers, fruits, and roots. Plants do this the same way we do, by "metabolising" the sugar and turning it back into energy (with carbon dioxide as a waste product). In plants this process is called "respiration". The glucose molecules are broken down and energy is released when needed for growth.

Excess glucose can be converted into another carbohydrate, called starch, which can be stored for future use. From these stored resources plants are able to re-grow next spring eventhough there is no green leaf tissue available to photosynthesize.

Photosynthesis is the process which makes it all possible. It is the process that harvest the energy from the sun. Without this energy harvesting process, plants could not eat, animals could not eat the plants, and we could not eat the animals. Photosynthesis is thus the ultimate energy generating source on the plant. It is also the process which "cleans the air" (exchanges carbon dioxide for oxygen). In summary, it is a crucial process for life as we know it.

"Contrary to popular belief, plants do not eat fertilizer (fertilizer is not plant food). "

Good point ...

Good Day ...

give them the ol' h2o + co2 (im sorry i cannot do the back and forth arrows) + light rays = c6h12o6 + o2.

they are gonna see that in their botany lives and they might as well get used to it. and in a very simple yet eloquent way, its a starting point for branching off into whatever parts u want.

froggy

Here is a essay on photosynthesis ... It's not just about plants anymore !!

An interesting essay on photosynthesis

Good Day ...

Everything you would want to know about photosynthesis ...

What is photosynthesis ?

Good Day ...

I would say that the plainer the better. Photosynthesis is a very complex process and it might take a long time to describe each step.
Photosynthesis is the process by which plants and other photosynthetic organisms (let's not forget cyanobacteria algae and diatoms) produce oxygen and organic material from CO2 and water.

Great links Mohave, thanks!

Nazanine ... you said simple but you had to make sure our bacteria friends and associates get a mention !! LOL.

Good Day ...

Yes Mohave :) one needs to be simple AND correct!

I think Kenneth (kdjeorgensen) gave a good explanation. I'd use his whole post in an FAQ. The PS equation is correct and succinct, but isn't really telling most people what they want to know. Kenneth also hit on a couple of widely misunderstood points: that fertilizer is not "food" in the same way we think of food and that plants respire as well as photosynthesize.

Kelly

Photosynthesis is a continuous process whenever sunlight is available.This will give more sugar available than plants will need on daily basis.Where does the plant store this extra sugar and what is the signaling process for this? Does plant stop the process of photosynthesis at the onset of scenescence?

chiman

I found the links referenced by the Mohave Kid very understandable ...I figure I'm about at high school senior level in this stuff. Thanks, Mohave.

Here's another site which I ran across which was helpful. josh

Here is a link that might be useful: Photosynthesis

Although I might be wrong (technically, I am at senior level), I think the so called "plant food" and chemical energy should equally be considered food, especially if you are comparing it to food for animals. The reason for this is that when someone eats grapes and energy is obtained through sugars (comparable to photosynthesis in plants), they also take in vitamins, minerals, and other nutrients (these do not directly supply energy). No matter what is in grapes whether I know it or not, the grape is still food cuz we eat it. I don't do much research in this area, but I would say that it would be practical to call both fertilizer and chemical energy (from photosynthesis) food for plants. The sun cannot supply plants with Fe, Mg, Mn, N, P, K, etc. even though it requires energy for these minerals to become useful to plants.

Carnivorous plants get nutrients from actively eating animals, and they also go through photosynthesis. There are also plants that don't directly depend on the sun but suck off of other plants.

Correct me if I'm wrong. Because I state only my opinion not about the science of photosynthesis, but mainly about the term "food".

www.dictionary.com:
Food (definition 1):
Material, usually of plant or animal origin, that contains or consists of essential body nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals, and is ingested and assimilated by an organism to produce energy, stimulate growth, and maintain life.
Eat (definition 1b):
To take in and absorb as food: a plant that eats insects; a cell that eats bacteria.

I would also like to acknowledge the fact that not all plants have chlorophyll. In The Manual of the Flowering Plants of Hawai'i (Wagner, Herbst, Sohmer-Bishop Museum, Univesity of Hawai'i press 1999) it states under the discription of the family Cuscutaceae "chlorophyll absent or scanty".

Gosh, Cyanea, now I figure I'm at Freshman level! Can I sit by you on final exam day? :) josh

You're exactly right, Cyanea. Sunlight, nutrients from soil, and CO2 from the air all components of plant "food," so it's all semantics. I don't like using the term "feeding" for fertilizing because it gives the impression that fertilizing is the sole source of plant "eating." People hardly ever say they are feeding their house plants when they set them in the sunshine.

Plants without chlorophyll are parasites on other plants.