Photosynthesis

Non-Cyclic Electron Flow

-Photosynthesis is the process of converting light energy to chemical energy and storing it in the bonds of sugar.

-It takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis.

-It occurs when the electrons from water are excited by the light in the presence of P680.

-Light energy causes the removal of an electron from a molecule of P680 that is part of Photosystem II.
-The P680 requires an electron, which is taken from a water molecule, breaking the water into H⁺ ions and O^-2 ions. These O^-2 ions combine to form the diatomic O² that is released.

-Through a series of redox reactions, the electron is transferred to an electron carrier PQ (as long as electron arrived PQ, protons are pumped in from stroma)

-Then the electron is transferred to B6F, more protons are pumped in from stroma.

-The electrons then move through PC and eventually attaching it to a molecule in Photosystem I.

- Light acts on a molecule of P700 in Photosystem I, causing an electron to be "boosted" to a still higher potential.

-The electron continues to pass through FD and FRN and eventually being attached to NADP⁺ and H⁺ to form NADPH, an energy carrier needed in the Light Independent Reaction.

-In Photosystem II, the pumping to H⁺ into the thylakoid and the conversion of ADP into ATP is driven by electron gradients established in the thylakoid membrane.

 

Cyclic Electron Flow

- Light acts on a molecule of P700 in Photosystem I, causing an electron to be "boosted" to a still higher potential.

- The electron continues to pass through FD, instead of going to FRN the electron is transferred to B6F.

-The electrons then move through PC and eventually back to a molecule in Photosystem I.

Calvin Cycle

- Glucose and other carbohydrates are synthesized in the carbon-fixing reaction of photosynthesis, often called the Calvin cycle.

- The carbon dioxide is attached to a five-carbon compound called RuBP, ribulose diphosphate, with an enzyme called rubisco.
- After carbon dioxide has been joined to ribulose diphosphate, a six-carbon product forms, which immediately breaks into two three-carbon molecules called 3-phosphoglycerate.
- ATP and NADPH₂ from the light reactions are used to convert 3-phosphoglycerate to 1, 3-phosphoglycerate to glyceraldehydes 3-phosphate, G3P, the three-carbon carbohydrate precursor to glucose and other sugars.

-One of the G3P leaves the cycle.

-The remaining 5G3P go through a series of steps to become the original RuBP.

-The cycle runs twice for make 1 glucose.

Enzyme Lab

Procedure:

1.       Line up three dry test tubes and label them 1, 2 and 3.

2.       Using a 10.00ml graduated cylinder and pipette, add 3.00ml of hydrogen peroxide into first test tube. This test tube will be used as the standard.

3.       3.00ml of hydrogen peroxide and 3.00ml of water are added into the same 10.00ml cylinder. Pour the solution into a clean, dry test tube to mix it. Using the same 10.00ml graduated cylinder and pipette measure 3.00ml of this solution, and pour it into test tube2.

4.       3.00ml of hydrogen peroxide and 6.00ml of water are added into the same 10.00ml cylinder. Pour the solution into a clean, dry test tube to mix it. Using the same 10.00ml graduated cylinder and pipette measure 3.00ml of this solution, and pour it into test tube3.

5.       Overflow pan is filled with water.

6.       Add water to fill the 1L graduated cylinder to the top and invert it into the pan. Record the volume of gas in the cylinder.

7.       Put 5 disks of liver in a 20.00ml Erlenmeyer flask. A rubber stopper with a funnel and tubing that extends into the 1L cylinder.

8.       Put the rubber stopper on the flask and pour the first test tube’s solution into the funnel. Cap the funnel with finger immediately and shake the flask.

9.       Record the time as long as the gas produced.

10.   Record the new volume of gas in the cylinder.

11.   Repeat step 6 -10 for test tube2 and test tube3.

12.   Clean up

Result:

	Test tube1	Test tube2	Test tube3
Volume of H2O2	3.00ml	3.00ml	3.00ml
Volume of H2O	0.00ml	3.00ml	6.00ml
Volume of the solution add into test-tube	3.00ml	3.00ml	3.00ml
Original volume of gas in the cylinder	75.00ml	66.00ml	67.00ml
Amount of gas after reaction in the cylinder	59.00ml	55.00ml	63.00ml
Total amount of gas produced	16.00ml	11.00ml	5.00ml
The time it used	11.60seconds	15.31seconds	13.52seconds

Thermodynamics

The first law of thermodynamics suggests that energy can be transferred from one system to another in many forms. Also, it can not be created or destroyed. Thus, the total amount of energy available in the Universe is constant.

The second law of thermodynamics also knows as the Law of Increased Entropy. Entropy is the measure of the randomness or disorder of a system. A more random or disordered system will have a higher entropy. Heat is a random form of energy, so adding heat energy to a system will increase its entropy. The second law states that nay process will generate some waste heat energy. This heat energy is random and increases the entropy ( or disorder) of a system.

The energy from the sun allows living organisms on earth to temporarily decrease entropy, but organized systems require an overall input of energy (provided by the sun) otherwise will break down. The second law also says that closed systems become more disorganized over time. Often this is expressed by the saying "entropy tends to increase".

The third law of thermodynamics states that if all the thermal motion of molecules (kinetic energy)could be removed, a state called absolute zeor would occur. Absolute zero results in a temperature of 0 Kelvins or -273.15° Celsius.