my biology page

1/ Purpose:

Learn why some substances passed across the membrane and other did not. Through that gain the knowledge to expain others real life experiences.

2/ Hypothesis:

- If the concentration inside the cell is higher than outside environment then some substances from the outside environment can pass across the cell membrane to get inside the cell.

- If the cell membrane doesn’t have the ability to avoid substances that maintain disease then through diffusion, the substances can get in the cell with the disease

- If lots of substances get into the cell can make the concentration inside the cell higher than the outside environment then some substances inside the cell might pass through the cell membrane to move out to the environment

3/ Materials:

- beaker

- onion skin

- dialysis tubing

- microscope

- string

- glass slide

- forceps

- starch solutions

- cover slip

- Iodine ( can stain your skin and is an eye irritant -> must wear safety goggles when using )

- bottle of salt water

- water dropper bottle

- teasing needle

4/ Procedure :

A – MAKE A “CELL”:

#1 Take a section of dialysis that has been soaking in water. Pull the ends apart, gently, forming a tube

#2 Seal one end of the tube by folding the end over and tying it closed with a piece of string or dental floss. The goal is to make that that end completely leak proof

#3 Pour the starch solution into the tube until it is about half-full

#4 Tide the top of the proof in the same way you tie off the bottom. The tube should not leak from either side. Check for leak by gently turning the tube to one end and back again, a few times.

#5 Rinse off the “cell” you have make my holding it under running water

#6 Place the “cell” in the beaker and add water until the “cell” is covered

#7 Put safety goggles over your eyes. Add iodine to the water in the beaker surrounding the “cell”. Add enough to make the water an amber color

#8 On your data sheet label the initial state diagram as directed

#9 Set the beaker aside and move to part B of this lab

B – OBSERVING AN ONION CELL

#1 After receiving the onion skin from the teacher position it in the center of a slide and place a drop of water on it. Be careful don’t let the onion skin fold over on itself. Use forceps and a teasing needle to get the onion skin flat.

#2 Add a cover slip and observe the cell using the low power of a microscope. Search for the cells with red coloration

#3 On your data sheet draw and color a typical onion cell mounted in water

#4 Remove the slide from the stage. Take the cover sheet off and bathe the onion cells in salt water. Take the cover slip back on the slide. Use the paper towel the plot the extra water.

#5 Place the slide back on the microscope and wait for a few minutes.

#6 While you are waiting, observe your “cell” sitting in the beaker. On your data sheet, label the final state diagram as directed.

#7 After completing the diagram, observe the onion cells in salt water.

#8 Draw and color an onion cell in salt water.

5/ QUESTIONS:

1/ Adding iodine into water can create a higher concentration environment out side the “cell” -> diffusion took place.

2 / The color inside the cell changed under the chemical reaction between iodine and starch solution.

3/ No starch diffused out of the “cell” because the water in the beaker still had the same color (while the water in the “cell” changed it color) -> the environment out side the “cell” was still the same (water and iodine)

4/ Iodine diffused through the membrane.

5/ The starch solution didn’t diffuse through the membrane.

6/ Some substances are able to pass through the membrane when others are not because dialysis tubing, like the cell membrane, is semi-permeable, which means it allows certain molecules or ions to pass through it by diffusion.

7/ The water inside the “cell” will not change its color (amber) while the water in the beaker changes its color into dark purple+blue.

8/ When the salt solution was added, an environment with higher concentration was created outside the onion cells -> osmosis took place -> the water inside the onion cells flow out.

9/ Organisms that contact directly with the salt can be badly damaged because the water inside cells of those will flow out the outside environment -> destroy the cell

10/

7/ OBSERVATIONS:

A – MAKE A “CELL”:

- The water in the beaker changed its color into amber after added iodine into.

- The cell changed its color into dark purple + blue after added iodine into the water.

B – ONION CELLS:

- Under the microscope the cell membranes and cell walls of the onion cells were seen.

- The onion cells increase sizes when added water and decrease sizes when added salt water.

8/ CONCLUSIONS:

A – MAKE A “CELL”:

The dialysis tubing played the role of the cell membrane in this experiment. Because it is semi-permeable, some certain substances can pass by it while others can not through diffusion. The iodine (mixed with water) in the beaker created a higher concentration outside the “cell” while the starch solution (also mixed with water) created a lower concentration inside the “cell” -> diffusion took place -> iodine diffused into the “cell”, have chemical reaction with the starch solution, this caused the water inside the “cell” changed its color into dark purple + blue. The starch solution couldn’t diffuse out of the cell so it didn’t make any chemical reaction with the iodine in the beaker -> the water there still kept its same color.

Diffusion also takes places in real life. It happens every seconds in our bodies and other organs through the cell membranes whenever a higher and lower concentration are created inside or outside the cell. This is the way for substances, both good and bad get into the cells and make changes.
B – ONION CELLS:

In this experiment, salt solution was added into the onion cells. This created a higher concentration in the environment outside the cells -> osmosis took place. Osmosis is a type of diffusion in which water diffuses through a cell wall or membrane or any semi-permeable barrier from a solution of low solute concentration to a solution with high solute concentration.

So in this case the water inside the onion cells diffused out into the outside environment (which has higher concentration) -> causes the cells decreased sized.

When added water the  balanced between the two environment  in and out side of the cells were recreated -> the water outside the cells diffused back in through the cell membranes -> the cells got back into original sizes.

Osmosis can easily being found in real life’s activities. Example when people tries to salted the food in order to keep it longer, it’s a kind of osmosis which the goal is taking all of the water out of the food to keep it dry and save from all kinds of fungi.

9/ POSSIBLE ERRORS: 

The dialysis tubing was not tightly tied or had holes -> some starch solution got out and got mixed with the iodine in the beaker.

-> Redo the experiment, make sure the dialysis is tied well and had no holes on it so nothing can get out.

Couldn’t see the changes of the onion cells through the microscope

-> Make sure you are having the right objective lenses and look for an area with lots of triangular shapes with dark barrier surrounds it and a small spot inside.

10/ RESOURCES: Wikipedia, Bio text book.

Sorry I didn’t noticed you have given us the paper with the questions on it. I’ve just found it today when I cleaned my bag pack

+ Summary for the movie:

Morgan tried an experiment on himself to prove if eating McDonalds fast food is bad for you or not. In the whole month (30 days) he just eats only fast food from McDonalds for his 3 meals. During the movie, information is showed to persuade people that eating fast food is an extremely bad habit that can causes lots of diseases and illnesses. After 1 moth Morgan has gained 24.5 pounds and his health was badly damged

+ Affections on other systems in Morgan’s body:

1/ Nervous system: massive headaches, mood swings, depressed and exhausted

2/ Digestive system: massive cravings

3/ Circulatory system: doubled chance to get heart failure and heart disease

4/ Respiratory system: hardly breath at night, lost his breathes sometimes.

5/ Skeletal and muscular system: hurt whenever he did exercises

6/ Reproduction system: worthless

+ Questions:

1/ My food choices are pretty good at the moment. I eat lots of veggies and fruits and whole grain stuff. I have fast food about 4 times a year. The only problems is I don’t drink enough water. I’ll try to improve that (at least 8 glasses a day)

2/ I will definitely avoid eating at fast food restaurant

3/ This movie actually scared me because lots of people that I know eat lots of fast food too. I have emailed some of them to tell about the movie and I hope at least it will help something

Thao Vu Lab period 6

1/30/2008 Class period 5

HOMEOSTASIS LAB: THE AFFECT OF EXCERCISE ON HOMEOSTASIS

1/ Purpose:

To discover the affect that various levels exercise have on specific body para meters

2/ Hypothesis:

- If the person keeps skipping with the same speed then the heart will beat faster after time.

- If the person need more oxygen during the time he/she skips then he/she will breath in and out more.

- If the temperature of the body raises then the person will sweat.

- If the person can take small breaks during the time time he/she skips then he/she can keep skipping longer with the same speed

3/ Materials:

- Skipping rope

- Thermometer

- Blood pressure/ heart rate kit

- Stop watch

- Ethanol

- Cotton balls

- Ethanol

- Cotton balls

4/ Procedure:

* before proceeding with the lab each group should be sure that they are able to obtain readings using the blood pressure kit. The kit should be attached directly to your skin just above the elbow joint. The black tube exiting the cuff needs to be resting on the inside of your arm at your elbow where a pulse can be measure. In order to avoid an “error” reading the subject need to be perfectly still when you are taking blood pressure/ heart rate measurements. Begin by inflating the cuff, using the black bulb, the monitor will beep when the cuff is sufficiently inflated. The monitor will take the blood pressure reading as it slowly releases air from the cuff. At the end both a blood pressure and heart rate reading should appear on the monitor screen.

- Choose one person in the group to be the subject.

- Record the resting observations and values of your subject for each of the 6 parameters:

+ Record normal skin color of hands and face

+ Record normal perspiration level

+ Record external body temperature by placing the thermometer under the subjects arm pit for 1 minut. Measurements should be taken directly from the skin.

+ Record the resting blood pressure and heart rate using the blood pressure cuff/ heart rate monitor

+ Determine the breathing rate by counting the number of breaths taken in 1 minute

- Have your subject begin to skip. Your subject should be sure to exercise at a level that they can maintain for the entire 8 minute.

- Take your subject parameter, using the same techniques showed below at the 2, 4, 6, 8 minute time markers. Be sure to take final reading 1 minute after your subject has stopped exercising

- Record all of your parameter readings in the table provided.

- After cleaning your thermometer with ethanol, return it along with your other lab materials to the front of the room

5/ Question:

1/During exercises the skin of subject changes from skin color to another color which is close to red and pink, subject also starts to sweat. This help to maintain homeostasis because sweating helps to cool down the body whenever the body’s temperature raises over 37 C degrees. The color of skin changes because more blood was supported to deliver energy to the cell

2/During cellular respiration, energy was made but also the process rises the temperature of the body.

Mechanism the body uses to maintain homeostasis temperature: sweat. The sweat leaves our skin through tiny holes called pores. When the sweat hits the air, the air makes it evaporate. As the sweat evaporate off your skin you cool down.

3/Heart rates and breathing rates increase to give the body enough oxygen and sugar (through breathing and the blood) to do cellular respiration -> make energy.

6/ Data and observations: 

7/ Conclusion:

When we exercise not only the skeletal and muscular systems do the job but also others systems involving to help maintain homeostasis :

- Excretory system’s work: sweating->releasing water+salt+sugar+ammonia+urea and cool down the whole body

- Circulatory system’s works: the heart beats faster, blood goes through veins contains oxygen and sugar (also the turning-back round blood contains carbon dioxide) to help maintain cellular respiration -> create more energy

- Respiratory system’s work: Breathing rate increases -> takes more oxygen and releases more carbon dioxide

- Nervous system’s work: control both the actions to skip the rope and the works to maintain homeostasis for the body.

Through all that homeostasis is maintained and the human body can work perfectly. Also it makes the body become more flexible with environment’s changing

8/ Possible error:

If the subject wasn’t given any breaks between exercising time then he/she could get exhausted easily and may not be able to complete the experiment

-> Divided exercising time in small parts (2-4 minutes each time) then gave the subject 2 minute break. Thoses breaks also help the whole team to have enough time to collect the data.

If the subject didn’t exercise enough then there would be no big changing in his/her body -> it could be hard to get and read the data+ observations

-> Choose enough time for exercising that wouldn’t completely make the subject extremely tired but still made some changes in his/her body that can easily being seen

8/ Resources: Wikipedia

Mrs. Winkler I couldn’t upload my data on. When I was doing my typing I clicked save like 1 time/ 10 minutes but then it all lost when I tried to put the data.

Purpose:

- Find out if fast foods really can have bad affections on people who eat it more than once/month

- Searching for the trues behind McDonalds’ food

- The link between eating fast food (McDonalds in this case) and having diabetes, over weights, heart failures…

Hypothesis:

- If you eat fast food everyday for your 3 meals and burn less than 1500 calories a day then you will soon be overweight after two moths.

- If you drink a lot of sodas and milkshakes in day time then you will have headaches later at night because of all the sugar you put into your body.

- If you eat fast food mostly everyday in a month then you will be food addicted even though you try not to eat it anymore in the next month.

Materials:

- A healthy man

- Fast foods.

- Medical checking’ equipments, doctors, nutrient advisers.

- A complete diet full with fast food.

Procedure:

- Begin with a man who has excellent health, take him to 3 doctors to check and take all possible observation (personal medical history, family medical history, weight, height, addiction, blood pressure, breath pressure, heart rate…)

- Make a diet plan with McDonald’s fast foods for 3 meals in a month. 4 followed rules:

1/ Just when he was asked for super size, he can order it. Otherwise he can’t have a supper size meal.

2/ Just eat only what McDonals (MD) sales.

3/ Must eat through everything on the MD’s menu in a month.

4/ Must have 3 meals a day

- Start the experiment, take possible data & observations every day.

Data:

Observation:

- Eachday MD serves 46 millions people all around the world

- 1/4 Americans choose to walk in a fast food restaurant for a meal everyday.

- 1/3 children born in the year 2000 can develop diabetes in their life times.

- There are only 7 item on the MD’s menu that don’t contain sugar: diet coke, fries, harsh browns, ice tea, coffee, sausage and chicken nugget

- There are at least 17 millions people suffered from diabetes type 2 all around the world in the year 2002.

- Weight gained -> breast cancer, colon cancer, gall bladder disease, respiratory problem, stroke, asthma and adult onset diabetes

Conclusion:

Through the movie and Morgan’s story, we can see that eating fast food is definitely a supper fast way to damage your health, gaining weight, having diabetes, heart disease… because:

- Unbalance diet with lots of fat and sugar but lacks on vegetables, healthy sugar (comes from fruit and veggie, rice…)…

- Processes food, mostly cooked by frying can cause heart disease.

- Sugar and fat all come from unnatural sources and whatsoever ingredients (old chicken’s meat, chemical sugar, chemical cheese…)

- The calories given are too high and most of them come from fat and sugar -> impossible for a person too eat fast food every day and use all those calories.

Besides, MD and other fast food restaurant are training us to eat fast food as much as possible. The kids are fed with high calories lunch meals at school, go over to MD with their parents and even when they are staying at home, tons of fast food’s commercials can be caught on TV. Time in gym class is limited, time to exercise after work is also as little as possible.

Although people is lacking on time now but stop eating fast foods, exercises and cook meals at home are easy, possible and cheap to do in order to get a good health, clean up the world’s environment, which is filling up with overweight, unhealthy people and help the kids to grown up in a better way.

Possible errors:

- Morgan weighted 203 pounds and later then after 8 days he weighted 202 pounds.
-> The true is Morgan is not getting skinnier, he just lost some muscle mass to gain some fat mass. As soon as more fat mass is gaine, he will pull up some pounds again.

- No information is provided in the fast food store and TV is filled with fast food’ commercials

-> the government, somehow should support the healthy food’s companies to introduce their products to the customers. Also open classes to talk about nutrients in everyday meals can be very helpful to.

- Kids don’t know what to eat

-> Parents, teachers and older people should teach children how to choose their food wisely and take away as much as possible the chances for them to eat fast food

#1:

+ The excretory system includes: kidneys, nephron, urine, large & small intestines, lung, skin, liver, spleen, lymph nodes, menses.

Malfunction can occur in excretory system: chronic kidney disease

+ Causes of Chronic kidney disease (CKD): The most common causes of CKD are high blood pressure, diabetes and heart disease. CKD can lead to kidney failure, but early treatment can slow or prevent this.

+ With other systems: 1/ high blood pressure, heart disease, anemia -> affect on circulatory system 2/ weak bones -> affect on skeletal system 3/ nerve damage -> affect on nervous system

#2:

Pair 1 includes: muscular system (left) and nervous system (right)

+ muscular system: producing motion, providing stabilization and movement, generating heat.

+ nervous system: the major controlling, regulatory, and communicating system in the body.

Nervous system controls muscular system’s actions (eat, run, walk…). Muscles helps to feel the environment ( hot, cold, hurt…) and reports to the nervous system.

#3:

Enzyme X had chemical reactions with sugar A and B to make disaccharides X+A and X+B, with sugar C to make monosaccharide X+C -> the 3 sugars include a particular molecule that can go with enzyme to create sugars.

#4: Viruses attack the internal environment

#5: Diffusion

#6:The astronaut breathes in more O2 and breathes out more CO2 -> the algae needs to do more gas exchange and photosynthesis

#7:

More lights -> the algae does more photosynthesis -> supports and takes more O2, CO2, water vapor…

OR: More lights -> temperature raises -> 1/water turns into air -> less water 2/guard cells (stomata) close to keep the water in for the algae -> does less gas exchange.

#8:

A/ Diagram 1

B/ A stomata.

C/ Result of malfunction: Stomata can’t open -> plants cannot gain carbon dioxide (without simultaneously losing water vapor)

#9: Figure D

#10: 1 enzyme can only goes with one sugar to make a pair

#11: Enzyme and molecule create a sugar together.

#12:

+ Already weakened virus or bateria

+ Strengthen the immune system by fighting back against the weaker virus or bacteria, so it’ll have the idea what to do with the real one

+ Advantage: Smallpox

+ Disadvantage: The returning of whooping cough

being with family and friends, painting, movies, TV, graphic books, good grades, ice creams, writing, travelling…

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