Photosynthesis Lab

This week in AP Biology we did a lab on plant pigments and photosynthesis. In the first part of the lab you get a piece of chromatoraphy paper and rub a spinach leaf on top of it with a quarter, so the pigment of the spinach leaf will be on the paper. You then put the tip of the chromatography paper into an alcoholic solvent, so the pigments will travel up the paper. When the pigments are completely done traveling up the paper, you measure where each pigment ends ( carotene, chlorophyll a, chlorophyll b) and  you calculate Rf values by dividing the pigment with the solvent. In the second part of the lab you get a spinach leaf and use a hole puncher to punch holes in the leaf to make leaf discs. After that you put the leaf discs in a syringe. Once the leaf discs are in the syringe, you fill the syringe up with. When the leaf discs are in the syringe with the solution make sure to make the leafs sink to the bottom by vacuuming the air out. Once the leafs are sunk, you then put the leaf discs into a solution which is mixed with water and baking soda (which gives off carbon dioxide) and you put the the leaf discs under a light source and calculate how many float to the top every 30 seconds.

Photosynthesis

This week in AP Biology we discussed about photosynthesis. Photosynthesis is the process where plants use sunlight to synthesis their food from carbon dioxide and water. I have been taught photosynthesis since elementary, but I never knew how complicated and complex it really was until we started learning about it in depth. Photosynthesis occurs in the chloroplast of the plant.There are two parts to photosynthesis, and they are the light reaction and the Calvin Cycle (also known as the dark reaction) . The light reaction occurs in the thylakoid membrane and it converts light energy to make chemical energy. The light that is absorbed is used to make ATP and also produces NADPH. The Calvin Cycle uses ATP as an energy source and also consumes NADPH so it can add high energy electrons to make glucose (sugar). There are three phases in the Calving Cycle. The first phase is called Carbon Fixation which is when carbon dioxide is made into a five carbon sugar called ribulose biphosphate or RuBP. The second phase is Reduction which is when ATP and NADPH are used to convert 3 phosphoglycerate to glyceraldehyde 3 phosphate which is the predecessor to glucose and other sugars. And finally the third phase is Regeneration. Regeneration is when even more ATP is used to convert glyceraldehyde 3 phosphate back to RuBP (which is the acceptor for carbon dioxide) so the cycle is complete. For the Calvin Cycle to continue this, the light reaction must continue regenerating ATP and NADPH. Without photosynthesis, anything that needs oxygen to survive will not be alive without it. Photosynthesis is one of the most important processes to occur.

Successful Blog

This week in AP Biology we redid our lab, and this time it was a success. To prevent the vials from getting water leaked into it, we used super glue instead of petroleum jelly which is what we used at first and that is how the lab failed last week. The purpose of the lab is to get germinated and nongerminated peas and put them in 6 vials with a cotton ball soaked in KOH. The vials 1-3 are placed in a room temperature bath and vials 4-6 are placed in a chilled waterbath. After that is done, you then place the 6 respirometers on each vial and place them in their designated waterbath. With the vials successfully done, we could now get the data we needed. This data was to show the relationship of gas laws to the function of a respirometer and the effect of temperature and germination or nongermination on cell respiration. The germinating peas consumed the most oxygen in both the room temperature waterbath and the chilled waterbath because it performs cellular respiration while the others do not. The lab seems fairly simple, but it is a very tedious process. 

Unsuccessful Week

This week in AP Biology, our class attempted to do a lab about cellular respiration. There are previous blogs that  explains cellular respiration and the steps that occur. This lab turned out to be a complete fail. I was not able to see the start of the lab because of an extracurricular activity, so I can't really explain the whole process, but the purpose of the lab is to demonstrate the relationship of gas laws, the effect of temperature and germination or nongermination on cell respiration, and the relationship between dependent and independent values. Like I said, I was not in class during the start of the lab, so I will not know as much or be able to explain it very well. However, the purpose of the lab is to get germinated and nongerminated peas and put them in 6 vials which has a cotton soaked with KOH. 1-3 is placed in a room temperature bath and 4-6 is placed in a chilled waterbath. After that, you place 6 respirometers  in the waterbaths, but our respirometers got water leaked inside, so it ruined the lab. If the respirometers did not get water inside, then we would have to record the volume.

3 Steps Of Cellular Respiration

This week in AP Biology we continued discussing cellular respiration once again. Since we have a quiz this week, we just reviewed about cellular respiration and the three steps of cellular respiration. These three steps are glycolysis, Kreb's Cycle ( citric acid cycle) and Electron Transport Chain (ETC). Each step works differently, but they each produce energy in the form of ATP. Glycolysis occurs outside the mitochindria and it breaks down glucose into two molecules called a pyruvate and also produces 2 ATP's and 2 NADH molecules.  The Kreb;s Cycle, which is also known as the citric acid cycle. The Kreb;s cycle occurs in the mitochondria where the pyruvates are transported and loses carbon dioxide to form acetyl CoA and later makes 2 ATP's, NADH and FADH. And finally ETC (also known as Oxidative Phosphorylation) also occurs in the mitochondria and it releases a large amount of chemical energy to produce about 34 ATP's. These are the three steps of cellular respiration.

Cellular Respiration

This week in AP Biology we talked about cellular respiration. Cellular respiration is the metabolic process whereby certain organisms obtain energy from organic molecules. Without cellular respiration, no organism would be able to acquire energy. Another thing we discussed in class was aerobic and anaerobic respiration. Aerobic uses oxygen while anaerobic does not use oxygen. Also anaerobic produces lactic acid while aerobic does not. Lactic acid is produced in the muscle tissues during an intense exercise. That is why when someone gets done with a difficult workout they pant for oxygen because your body is getting all of the lactic acid out and taking oxygen in. There are three steps in cellular respiration, and they are glycolisis, Kreb's cycle, and Electron Transport Chain (ETC). Each one of these steps build up on each other to make several ATP's. (I don't know the cycle very well enough as of now to explain it very thoroughly). Cellular respiration is very important to any organism because we need energy to make our body work properly.

Gibbs Free Enegy

This week in AP Biology we talked about Gibbs Free Energy. Gibbs Free Energy is a bit confusing, but after a while you start getting the hang of it (I don't know it well enough to explain it very well). Free Energy is very important in the universe. Without Free Energy, then nothing would be the same and our body wouldn't be able to function as quickly as it does now. Another thing we talked about in class is enzymes. Enzymes are simply proteins that speed up reactions. If we didn't have enzymes then it would take years and years and years to even digest the simplest things. Another thing we talked about is metabolism. A metabolism is the chemical processes that occur within a living organism in order to maintain life. Without any of these things, our body would not be able to function as well as it does now.