Light Reactions

* Occurs only when Light is present.
2. Takes place in grana / thylakoids.
3. Chlorophyll molecules trap light.
4. This cause their electron's to absorb much energy, became energized and start to flow.
5. Energy to flowing electron is used to make ATP (adenosine triphosphate- a high energy molecule.
6. Light Energy is charged to the energy flowing electron in turn changed to chemical energy in ATP.
7. Water enters the grana split into hydrogen & oxygen.
8. Hydrogen attaches to NADP becomes NADPH - a hydrogen carrier molecule.
9. While oxygen moves out through the stomata into the air.
10. The important products of light energy / reaction are ATP & NADPH, which are both needed in dark reaction takes place.

Key Ideas

Similarities
They all use glucose as starting material with aTP as-end product.


Differences
Oxygen is starting material in respiration but not in alcoholic and actic lacid fermentation.

Respiration produces more ATP compared to alcoholic and lactic fermentation.

Respiration produces carbon dioxide and water while alcoholic fermentation produces ethyl alcohol and carbon dioxide. Lactic acid is produced by Lactic Acid fermentation.

Respiration is the most efficient because it produced ATP molecules. Respiration produces 36 ATP per glucose molecule compared to 2 ATP in alcoholic and Lactic acid fermentation.

The Three Major Steps in Cellular Respiration

Glycolysis takes place in the cytoplasm, in aseries of reaction, glucose is broken down into pyruvate. Energy released and trapped in two molecules of ATP. Pyruvate moves into the mitochondrion.

The second major reaction of respiration is called the Krebs Cycle. It is named after the scientist discovered the different steps in the cycle. The Krebs cycle takes place in the liquid part of the mitochondrion here, acetyl coenzyme A (acetyl CoA) w/c is formed from pyruvate enters the cycle. Sveral substances are formed w/c are used again. But three products move out of the cycle. These are carbon dioxide w/c leaves cell, two molecules of ATP, and the hydrogen carrier, AH2.

AH2 passes into the cristae where the third major reaction occurs. AH2 break down into hydrogen and electrons (e). The electrons flow from one electron acceptor to another. As the electrons flow, energy is released forming a total of 32 ATP molecules. The last electron acceptor is oxygen w/c finally forms water with hydrogen.

The simple disscusion illustrates the gradual breaking down of the glucose molecule. Energy is slowly released and captured in ATP. For every molecule of glucose, a total number of 36 ATP molecules are formed.

Diffusion

An example of Passive transport is diffusion, the process by which particles spread through a liquid or, a gas medium. In diffusion, the net movement of particles is from a region of higher concentration to a region of lower concentration. In cells, water and alcohol easily diffuse across the plasma membrane.

Types Of Fertilizers

Natural (organic) ~ made from decayed plants, animals & human waste. Useful in recycling soil nutrients & promotes the growth of helpful organisms.

Artificial (inorganic) ~ produced from petruleum based chemicals w/c are harmful from plants & microorganisms. Theey can also contaminate groundwater source.

Water Cycle

When there is a precipitation~whether rain, hail, or snow~water from the atmosphere falls to the Earth. Some of the water reaches the ground and travels to become part of lakes, rivers, or oceans. Other parts sink and form groundwater. Water cycle involves evaporation, condensation, and precipitation. This cycle transform water into different phases.

Science Ideas

* Microtome - is the instrument used to cut specimen very thinly in sude preparation.

* Microforceps - are used to move material and insert a new ones in cells.

* Microelectrodes - measure electric current within cell.

* Micromanipulator - translate arge movement of the hand into microscopic movement.

* Microdissection - is a method of replacing cell organelles like the nucleus to help determine it's function.

* Intermediate Filaments - are studied in the detection of possible origins of cancer.

* Smooth (E.R) - synthesis enzymes involved in detoxitification.

* Cell Membrane and Cytoplasm - are directly preservation of food.