Pre-AP Biology

Photosynthesis Experiment


1. To prove that chloroplast is responsible for photosynthesis.

2. To prove that chloroplast makes electron, which makes electricity.


First we prepare 3 beakers, and fill 3 of them with 200 ml of distilled water. Label them 1, 2, 3. Add K2HPO4 to beaker 1 and 2, and add sugar to beaker 3. Making 3 solutions. Then we make a clean spinach juice that includes a lot of chloroplasts, using spinach leaves, which we teared off the stems, putting that in a blender, and then we filter the thick juice we blended, to get the clear spinach juice with a lot of chloroplasts. Then we get 4 test tubes, filling each with one drop of DPIP, and then we put some given amount of spinach juice to each tube, except the third tube. Then we place the 4 test tubes in different environment, the 1st one will be lighted by the sunlight, 2nd one will be microwaved first, and then will be lighted by the sunlight, 3rd one only has DPIP, and will be lighted by the sunlight, 4th one will be same with the 1st, but there will be no light going in the tube, so we place it in the drawer. After leaving the tubes for 2 days, we take 1 mL out of 4 solutions, putting them into a tube with 5mL of tap water. Then we shake and stir the tube mixing it. Finally we put that new solution into the crystal tube until half is filled. Then we go to the laser machine. Then finally we will compare the result, checking if photosynthesis has happened or not.


Our results looked really wrong compared to others. The average result from the laser machine is from 1.2 to 1.4, but our results are far away from these numbers. For example, the first tube’s result which is the one with the sunlight is 1.96, which is very high and unusual. The second tube wasn’t supposed to do any photosynthesis, because we microwaved it which means it had to be dead. But looking at the results, it did. The fourth one that we shut down the lights also did photosynthesis. Except the third one which only has DPIP. Tubes except the 3rd one’s stopper popped during the 2 days we left it. This means it created oxygen which made the stopper pop, which means it did photosynthesis. Every tube except the 3rd one showed sign of it doing photosynthesis.


We could have made this experiment work better by doing several things, or doing it the right way. We could have microwaved the juice more on the second tube, because by the end of the experiment it has shown that the chloroplast didn’t completely died off. So we could have done a better job in killing off the chloroplasts completely. For the 4th tube, we could have done a better job by placing the tube in a place that is completely dark, because the 4th tube’s stopper was also popped showing it did photosynthesis, which means there was some light to do photosynthesis. We could have also done a better job diluting the juice and the water better, because it showed on the results that some wasn’t completely mixed. We could have done a better job diluting the juice and the water better by stirring it more, or shaking it to bring up the chloroplasts which is sunk to the bottom. Maybe we made some few mistakes in measuring the amount of tap water, solution, juice, etc. We can’t do anything about this, because we are humans and no human can measure things completely correctly. There is also an uncertainty on the cylinder, which is 10+0.2mL, making the water 10.2mL instead of 10mL. We might have measured the amount of K2HPO4 putting in the water. When the stoppers popped, maybe bacteria went into the solution, eating up the chloroplasts and the glucoses, making the razor machine giving wrong results. There is a possibility that we didn’t 0 the razor machine before measuring it, making certain changes in the result. Maybe the crystal tube had some leftover solution stuck somewhere in the tube, which made it mix the solutions, making something completely new, changing the results. We could be way more careful not to let anything touch the crystal part.

Cellular Respiration Experiment

Purpose: To find if living things and non-living things take in oxygen and releases carbon dioxide.

Hypothesis: I think the living things will breathe in and out, because their lungs are moving which is causing the respiration system to work. This will force them to breathe in and out. But I don’t think the non-living things will breathe in and out, because when they are dead or not living, there can be no respiration system or any other system working properly. So there will be no oxygen getting breathed in. But because of the dead skins and the environment, there could be some carbon dioxide getting out from the dead bodies. So my hypothesis is that from the living bodies, there will be oxygen getting in, and carbon dioxide going out, but from the dead bodies there will be no oxygen going in at all, but there will probably be some carbon going out.

Equipment List:

  1. Peasx32
  2. Dead Peasx32
  3. Boiling tubex3
  4. Rubber stopper x3
  5. Paper ballsx32
  6. Ruler
  7. Cottonx6
  8. Plastic tubes x3
  9. Tweezers
  10. Food coloring or marker ink
  11. Water
  12. Sink
  13. KOH (Potassium Hydroxide)
  14. Microwave
  15. Beaker


Alive Peas: -2cm

Dead Peas: -0.2cm

Paper balls: +-0 (no change)


If we look at the table, alive peas moved the furthest comparing dead peas and paper balls. This means that alive peas are doing respiration, but not paper balls, which is a non-living thing. Dead peas are supposed to be dead, because we microwaved it, but some part of the pea should been alive, and that is doing the respiration even though it is a very small amount. We then can conclude that alive peas are releasing oxygen when they come together with KOH. Even if KOH might not be there, there would have been changes just because it is alive, but the number won’t be as great as this one.



・By looking at the table or the result, we can see that even though it says “dead peas”, it is not fully dead yet. Most probably it’s because my team member didn’t microwave the peas properly. If the change is 0.2 cm, then some parts are still alive, so we got that number, which we shouldn’t if it is “dead”.

・Also when Mr. Brian used the KOH; I noted down that he was using this beaker.

・Although it might not connect with this, but when he took the cotton and dip it, there should be some time uncertainties. Also the power he squeezed that cotton to the beaker should not be always exactly equal.

・Paper balls we made weren’t all in an equal size.

・Marker ink or food coloring was putted in the tube randomly.

・The 15 cm ruler should have uncertainty.

・Microwave might not maintain its warmness when heating something.



4 Macro Molecules
Carbohydrates – saccharinous
No one can avoid carbohydrates
They are the source of all energy available to us
Made of sugars
Diasaccharides (two monosaccharides)
Sucrose (Glucose+Fructose)
Polysaccharides can contain thousands of simple sugars – storing energy
Lipids – oleaginous
They are usually solid in warm blooded animals. They are oils for cold blooded animals.
It is made of hydrogen, oxygen, carbon
Smaller and grouped together than carbohydrates
When there is many phospholipids, it is called fatty acid
Fatty acid – long chains… take 3 of those and connect them with glycerol, you get triglyceride
Phospholipid makes cell membrane wall (head = polarity[attracted to water])(Tail = non-polar[avoid water])
Take one fatty acid and replace with phosphate group makes phospholipid
Another lipid is steroid
Cholesterol and can form into lipid horomones
Proteins – albuminous
Does everything in our body to keep us alive
Helps digest food because of enzymes
Protein horomones
Proteins use 20 different ingredients called amino acid
Makes valin, building/protecting muscles(Actin and Myosin)
Tryptophan helps you regulate mood and energy levels
It can form chains of same kind called the polypeptides
They come in all kind of structures, they fold, they coil
There are 9 of the amino acids that we cant make our self
Histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
Form long fibers. Alpha keratin(Horns, Hooves, Nails, Hairs etc.) Collagen (Skin, Catilage) Microtubules and Microfilaments (Cell Support, Cell division, cell transport)
Nucleis Acids
DNA and RNA makes 4 nitrogen bases. That has 4 different symbols. A, G, C, and T. It’s good for communication.
A – Adenine
C – Cytosine
T – Thymine
U – Uracil
G – Guanine
DNA is a nucleic acid
Most complicated job of all

Cell Components

Nucleus – manager
-brain of the cell

-it controls the cell’s activity

Golgi complex – waiter

-it packages and labels items which is then send to different parts in the cell.

-It is also involved in the creation of lysosomes.

Cell membrane – security
-it controls how substance can move in and out of the cell.

-Protect cell from outer force.

Ribosome – chef/barmen
-it makes proteins (using the amino acids)

-Nucleus sends message to the ribosome through the RNA, telling the ribosome to make proteins.

Lysosome – maid
-breaks down waste material

-transport undigested material to the cell membrane for removal

Glycoproteins – Advertiser

– Immune system and help our body determine what is ours and what is foreign

– It helps stabilize the membrane structure as they form hydrogen bonds with water molecules.

Endoplasmic reticulum –Handyman

-To carry essential substances from one part of the cell to another.

-It forms an interconnected network of vesicles, etc.

Vacuole – Storage

– stores the waste of the cell.

-removing unwanted structural debris around from the cell.

Cytoskeleton – Path

– It keeps all the organelles in place.

-It lets the organelle travel on it.

Vesicles – Serving Trays

– Small packages containing substances/chemicals and they float about in the cell, until, they are secreted

-Stores or transports substances within a cell.

Peroxisome – Trash Disposal

– Breakdowns the fatty acid molecules.

-Converse acids to water and oxygen.

Mitochondria – Generator

-They generate the energy that the cell needs.

-It stores energy, and converts foods into use inside the cells.

Chloroplast – Take Energy

-it converts light energy into energy that can be stored in the plant (photosynthesis).

Lab Report of the Enzymes Experiment

Purpose :To see how sugar affects the rate of the chemical reaction inside the solution. To look at the production of oxygen and gas inside the solution.

Equipment list :

  1. 4  potatoes (size doesn’t matter)
  2. Mixer
  3. Filter
  4. 1 large beaker (500mL)
  5. 2 small beakers (20mL)
  6. 2 small cylinder beakers (10mL)
  7. Filter Paper
  8. Puncher (to make holes in the filter paper)
  9. Glucose
  10. Hydrogen Peroxide (60mL)
  11. Weight Measurer
  12. Stirring Spoon
  13. A normal spoon
  14. Tap water
  15. Paper
  16. Timer
  17. Tweezers


  1. Calculate the amount of sugar in one mole, which is 18.016 grams.
  2. Calculate the amount of sugar for 0.2mole, 0.4mole, 0.6mole, 0.8mole, by multiplying 18.016 with the mole numbers.
  3. Divide all answers of each mole multiplication by 5.
  4. Put some random amount of glucose on the weight measurer, and try to make it as accurate to the amount of glucose we calculated.
  5. Make 5 small boxes using paper to put in different amount of glucoses.
  6. Label the 5 small boxes 0.2, 0.4, 0.6, 0.8, and 1.0.
  7. We put the amount of glucose we calculated and put it into each box we labeled. (Put 0.2moles of sugar into the box labeled 0.2)
  8. We make the potato juice by putting 4 potatoes in the mixer, with 200mL of water and we mix it.
  9. Blend it until it looks like soup.
  10. Take the mixer cup and pour it into the large beaker.
  11. Take 1 filter paper and one small beaker which you can put 20 mL or more, put the filter paper on top of the beaker and make sure it would point inside the beaker.
  12. Pour some potato juice on the filter paper.
  13. Wait for the potato juice to create the potato enzyme liquid, which should come out slowly over 1-2 minutes.
  14. After about 10 to 15 mL of enzyme liquid came out, you won’t use the potato juice anymore, so throw it away.
  15. Then we get 10 mL of Hydrogen Peroxide, and 10mL of water, and pour it into the beaker. Use the small cylinder beaker for measuring accurately. (We do this 6 times)
  16. Punch 18 holes of small circles using the puncher (We repeat the experiment 3 times each for each mole)
  17. We then put the measured glucose into the beaker, not in once but one at a time (0.2, 0.4, 0.6, 0.8, 1.0).
  18. We mix the solution.
  19. Pick up one circle made by the filter paper created by the puncher, using the tweezers.
  20. Dip the circle into the potato juice for around 10 seconds, making sure it is soaked completely.
  21. Dip the circle which is soaked into the peroxide solution, and push it to the really bottom of the beaker.
  22. Get your timer ready.
  23. Start your timer as you let go off the paper, and stop the timer when the paper floats up.
  24. We repeat this 18 times, doing 3 times for each mole. We throw away the solution we used for one mole, and make a new one for the other moles. Nothing changes in the process, but only the amount of glucose we put in. Such as 0.2 molar, 0. 4 molar, 0.6 molar, 0.8 molar, 1.0 molar. We note the results and calculate the average for each mole. (0.0 put no glucose at all)

Hypothesis: I think the 1.0 glucose beaker’s paper will float up quicker than the 0.0 glucose beaker. I think 0.0 will be slow, and as the amount of glucose rises I think it will take less time.


Beakers (mole) first Attempt (sec)   second Attempt (sec)   third Attempt (sec) Average (sec)

0.0                        8.97                            8.64                                  12.68                         10.1

0.2                        5.68                            5.24                                   5.54                           5.5

0.4                        5.55                            4.84                                   4.48                           4.96

0.6                        5.58                            5.5                                     4.45                           5.2

0.8                        5.28                            6.07                                   5.31                           5.6

1.0                        1.92                            1.4                                     1.19                           1.5

Conclusion – There is a huge difference in time when we see the average of 0.0, and 1.0. There is a slight curve between 0.2molar to 0.8molar. It went to 5.5sec at 0.2molar, and 4.96sec at 0.4molar, but it came back up at 0.6molar, with an average of 5.2sec, and it went higher at 0.8molar with an average 5.6sec.At 0.0molar, first and second attempt was about 8-9 seconds, but at the third attempt it suddenly goes up to 12.68sec. The paper that went into the high glucose water was more fuzzy and soft then the low concentration of glucose water. On the Graph, from Sugar Concentration (moles): 0.0moles to 0.2moles, there is a slope that really goes down quickly; it goes down from 10 sec to 5.5 sec. From 0.2molar to 0.4molar there is a lenient slope going down slowly, compared to the last one. It goes from 5.5sec to 4.9 sec. From 0.4molar to 0.6molar, there is another lenient slope but is rising from 4.9sec to 5.3. From 0.6molar to 0.8molar it rises again from 5.2sec to 5.6sec. From 0.8molar to 1.0molar, there is a quick slope going down, similar to 0.0 to 0.2. It goes down from 5.6 to 1.5, making a huge difference.

Analysis – We made a few errors and could make this experiment work out better or work out quicker. We made tons of human errors. All the part which we said we measured can’t be the exact number what we said. It is always different or wrong. There is no human being which can exactly measure something. So it is called a human error. We are supposed to make this error, so we can’t change this into a better way, unless we let the robots do it. We also didn’t use our own potatoes to make the juice. Because we were running out of time, we used the other group’s leftover, which wasn’t actually ours. We could have different results if we used our potatoes, instead of others’ potatoes. We also didn’t use exact 18 circle filter papers for the experiment, since I blew my nose and about 8 of them disappeared, we used 26 holes. This was another error. Because my hand shook when I was holding the beaker0.2 and 0.4, some of the liquid fell on to the ground. Which made the liquid reduce by a small amount, which also changed the test result. We could also do this experiment more efficiently by not making the solution over and over, and adding different amount of glucose to each solution. We could have begun with the smallest amount of glucose, which is none, and added 0.2molar of glucose again and again to the same solution, so we could have not wasted hydrogen peroxide and glucose. Because if we did this in this way, we could prevent huge amount of wastes and save ourselves some money and help the environment. It would also probably made the experiment end way quicker, because what we have to do is to keep adding 0.2 molar of sugar. Which we didn’t that was pretty dumb. We kept making the same solution, and measured different amount of glucose for each solution, which probably took about 3/4 of our time. It would also be quicker if we gave each other a job to do. Because we were doing 1 thing as a group, and 2 people wasn’t doing anything which was my fault as a leader. If I could give them specific options and commands, we could’ve done this experiment quicker. We also could have used smaller measuring tools because we did it pretty roughly. We didn’t care if there was a difference about 1 mL, because we were running out of time. If we went to that stage earlier with loads of time, maybe we could have used smaller tools to make the results of this experiment way more accurate.   

Lab Report of the juiciest fruit experiment
Purpose of this experiment: To find the juiciest fruit, and prove how juicy it is scientifically. To find how the amount of glucose we put in the water affects the fruit, and why. To find if the fruit gets heavier or lighter.
Equipment List:
1 whole watermelon
Knife (we used a ruler)
6 beakers (same sizes and better if its not too big)
glucose (about 50 grams)
weight measurer
1. label the 6 beakers as 0.0, 0.2, 0.4, 0.6, 0.8, 1.0.
2. Put 100 ml into all 6 beakers.
3. Make the solutions by putting each amount of glucose into the 6 beakers. (for 0.0 put nothing, for 1.0, 18.016 then calculate the others.
4. Mix the glucose with the water.
5.Cut the watermelon into 18 pieces. Measure 3 pieces of watermelons before putting it in the beaker, and record it. Then put 3 pieces in each beakers.
6. After 30 minutes, measure the weight of each pieces in different beakers, to see what happened in the 30 minutes.
I think for 0.0, because the fruit sucks in water, it gets heavier, and as the amount of glucose rises, it gets lighter. So, 0.0 will get heavy, and 1.0 will mget lighter.
Beakers        Before       After        Difference
0.0                 4.37         4.68        0.31=7.1%
0.2                 4.56         5.49        0.93=20.4%
0.4                 5.21         5.42        0.21=4%
0.6                 4.78         4.87        0.09=1.9%
0.8                 4.34         4.38        0.04=0.9%
1.0                 4.76         4.74       -0.02=-0.4%
How juicy watermelon is: 0.94 molar
As the X-axis gets bigger, the points goes up and down from 0.0 to 0.6, making a slow move. At 0.8 it suddenly drops low from 4.8 to -0.01, and has a slight difference to 1.0, with a tiny bit of a drop. The melon looked fuzzy when  it was closer to 1.0, because it is releasing water instead of absorbing it in, and if it was closer to 0.0, it looked tight because its getting in more water.The watermelon is cutting the X-axis at a 0.94, which is telling that watermelon is really a salty fruit.
Analysis: We made a lot of errors in this experiment, so it didn’t work out too well, we can’t measure the weight to the exact number, so this is a human error. Watermelon can’t be the most salty fruit, it should have more water then salt. But, watermelon is the saltiest fruit, compared to kiwi, which had a 0.36, apple, which had a 0.61, potato, which had a 0.42, dragon fruit, which had a 0.78, mango, which had  the same result with dragon fruit, 0.78. This is saying that even potato has more water then watermelon and other fruits, so I think potato group also made some mistakes. We could have measured better by using smaller equipments, and taking a lot of time. But, because we went on this experiment with a rush, maybe this result came out. The watermelon of 0.6 and 0.4, from my look one of the melons wasn’t submerged properly, so that is another mistake we made. We also used the tap water, which could never be 100% pure water, especially because of the flood that we had last year, which made the water muddy, and dirty. When we were also measuring the glucose, we also made an error by not looking for the weight measurer to have a 0.0, and that could have added some extra weight to some of the melons we measured. Another error is that when we were measuring the glucose, we didn’t put in what we exactly measured on the measurer, because some tiny pieces of glucose fall off, and some were sticking on to the measurer. The water which was in the beakers also could not be 100% 100 ml. It is another human error.

The pictures of Selectively Permeable Experiment


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