Photosynthesis

Photosynthesis
By Mackensie Nelson and Hunter Karl

Tuesday 14 May 2013

What happens to glucose after it is made in photosynthesis


What happens to Glucose;

In vascular plants, much of the glucose made during photosynthesis is converted into cellulose in order to build and repair cell walls.
After this, some of the glucose is converted to starch and stored.
The glucose is used directly in cellular respiration, which results in the production of ATP. The energy stored in ATP goes to build molecules such as cellulose, starch and proteins. ATP also fuels active transport, or transport of materials against concentration gradients. Active transport is especially important when transporting minerals into the plant from the soil against their concentration gradient.

Describe the Process of Chemiosmosis in the making of ATP


Chemisosmosis


In chemiosmosis, chloroplasts, protons (H+) are pumped through electron transfer to one side of the membrane, creating a gradient, which then allows them to diffuse back across through ATP synthase. This process allows ATP to be produced from ADP + P.


In chloroplast, the H+ are pumped into the thylakoid membrane space and then diffuse back out to the stroma. This causes ATP (like NADPH) to be produced in the stroma, which makes it readily available for the Calvin cycle.

An increase in light causes an increase in the amount of H+ that is pumped into the thylakoid membrane. The pH gradient will not occur if there is no light, as the process needs light energy to work.

Describe the Reduction and Oxidation that occurs in Photosynthesis


The main chemical reaction that takes place during photosynthesis is:

               (light)
6CO2 + 6H2O------------> (C6H12O6) + 6O2

"Plants breathe in carbon dioxide and breathe out oxygen". This is the overall chemical formula that shows how that works.

This reaction, however, is really the result of two separate processes.

1.      Splitting the Water Molecule

The chemical equation that shows the splitting of the water molecule is shown below:
               (light energy)
12 H2O -----------------------> 6 O2 + 24 H+ + 24e-

For every 12 molecules of water, 6 oxygen molecules are released. This is accompanied by the release of 24 hydrogen atoms and 24 electrons. Since the water molecule is losing electrons in this reaction, the water molecule is said to be oxidized.
2.      Conversation of Carbon Dioxide to Glucose

The chemical equation that shows the conversation of carbon dioxide to glucose is shown below:

CO2 + 24 H+ + 24 e- ------> C6H12O6 + 6 H2O

In this reaction, carbon dioxide, in the presence of hydrogen ions and electrons is converted to glucose and water. Since carbon dioxide is adding electrons, it is reduced.

Breakdown the process of photosynthesis into its two stages


1. In the light-dependent reactions, there are two photosystems. In Photosystem 2, H20 splits into H+ and O2. Since there are two hydrogen and only one oxygen molecule, it is written out as 1/2 O2. The splitting of water creates electrons. Sunlight hits the electrons and they become excited, so they travel upwards to the primary electron receptor and bounce down the electron transport chain until they reach Photosystem 1. Energy from the traveling electrons travel through the ATP synthase along with H+, which makes phosphate. Outside, ADP is made into ATP by adding that phosphate. Meanwhile, light hits the electrons and they become re-energized, traveling back up to a second primary electron receptor and going down the electron transport chain until it travels outside. There, two electrons make NADP+ and H+ into NADPH. The ATP and NADPH travel onto the Calvin Cycle.

2. In the light-independent reactions, 3 CO2 enters the cycle and latches onto 3 5-carbon. This is unstable, therefore each one breaks into 2 3-carbons. Traveling onward, ATP gives up a phosphate to one, so a set looks like ATP is now ADP. Then, NADPH oxidizes them. NADPH is now NADP+. There are now 6 G3P molecules. 1 breaks off and while the five move on. This is so that when another round occurs, the 2 3-carbons can form a sugar. As for the other five, 3 ATP give up a phosphate while the hydrogen drops, so now there are 3 ADP.  The cycle begins all over again.

 
 

Explain how pigments absorb light in Photosynthesis

How Pigments absorb Light In Photosynthesis
 
Pigments are chemical compounds which reflect only certain wavelengths, flowers, corals, and even animal skin contain pigments which give them their colorsisible light. Because they interact with light to absorb only certain wavelengths, pigments are useful to plants and other autotrophs. Pigments are "molecules that absorb specific wavelengths (energies) of light and reflect all others."
There are three different types of Pigments;
 
-Chlorophylls are greenish pigments which contain a porphyrin ring.
-Carotenoids are usually red, orange, or yellow pigments, and include the familiar compound carotene, which gives carrots their color.
-Phycobilins are water-soluble pigments, and are therefore found in the cytoplasm, or in the stroma of the chloroplast.
 
 

The overall Balanced Equation For Photsynthesis


THE PHOTOSYNTHESIS EQUATION

Where the arrow is, is where light is being transformed in the reaction.
Light energy enters the plant through the leaves and the water and nutrients enter through the roots. The plant is then able to produce starch and oxygen and the oxygen exits out of the leaves for us to breathe.

       6CO2 + 6H2O → C6H12O6 + 6O2

What is the Importance of Photosynthesis On Earth?

The importance of Photosynthesis
 


The importance of Photosynthesis on our earth is, Without photosynthesis on the earth, the earth would be a dead planet because, the cycle of energy flow would be prohibited and all animals (that can't produce food) would die.
 
Another Importance to Photosynthesis is, It is important to life on Earth because we all breathe in the oxygen that the plants produce for us.
 
Another importance is; The food in the plants can then be eaten by animals, since animals cannot convert solar energy to glucose, photosynthesis creating energy becomes very helpful in our animal life and humans.