Plant Transpiration Lab

Data:

Plant type	Normal (mL)	Fan (mL)	Heater (mL)	Lamp (mL)
Arrowhead	3.6	7.5	6.6	4
Coleus	0.9	6	3.9	3
Devil's Ivy	2.9	4.6	4.1	3
Dieffenbachia	4.1	7.7	6	3.9
English Ivy	1.8	5.1	3.2	2.1
Geranium	1.2	4.7	5.8	2.4
Rubber Plant	4.9	8.4	6.8	4.3
Weeping Fig	3.3	6.1	4.9	2.5
Zebra Plant	4.2	7.6	6.1	3.2

1. Describe the process of transpiration in vascular plants.

The process of transpiration occurs when vascular plants releases excess moisture and gains nutrients.

2. Describe any experimental controls used in the Investigation.

Time stayed constant in every single experiment of one hour.

3. What environmental factors that you tested increased the rate of transpiration? Was the rate of transpiration increased for all plants tested?

The environmental factors we tested were heat, wind, temperature and light. The rate of transpiration indeed increased at different times for every plant tested.

4. Did any of the environmental factors (heat, light, or wind) increase the transpiration rate more than the others? Why?

Wind had the most effect on the transpiration rate than other environmental factors, because winds could blow the water of leaves quickly or dry them up. The process of osmosis would then occur because the leaf would release water.

5. Which species of plants that you tested had the highest transpiration rates? Why do you think different species of plants transpire at different rates?

The Rubber Plant had the highest transpiration rates possibly because the environment they naturally grow in calls for more transpiration to balance the water. 

6. Suppose you coated the leaves of a plant with petroleum jelly. How would the plant's rate of transpiration be affected?

There wouldn't be any transpiration because the jelly would cover the stomata's of the plant.

7. Of what value to a plant is the ability to lose water through transpiration?

Transpiration helps the plant achieve homeostasis in temperature as well as the transportation of nutrients from roots to stem. It also helps the photosynthesis process of the plant.

Plant Hormones!

Plant Hormones!

Auxins:

Hormones in the plant that serves many functions. They are like the growth hormone of the plant by stimulating stem elongation and softening of cell wall. The most common naturally occurring auxin is Indoleacetic acid (IAA). Auxins spur the growth of the plant, and boosts root growing speed. Other functions of the auxin includes enhancing apical dominance, where a plant will prefer to grow towards the direction of the sun vertically rather than laterally.

Abscisic Acid (ABA):

These hormones maintains plant health and homeostasis during shifting environmental factors. It serves as a counter-hormone to Auxins by inhibiting growth and promoting seed dormancy. Furthermore, during times of drought or low water availability, it allows the plants to survive by closing the stomates.

Ethylene:

The unusual thing about this hormone is that it is a gas. It functions under positive feedback and it promotes ripening of fruit. Once a fruit ripens, there is also a increased production of ethylene gas. When there is a barrel of apples, and one apple became ripe, the whole barrel will soon go bad due to the ethylene gas triggering faster ripening in the other apples. Hence the old adage "One bad apple spoils the whole barrel."

The Botany Of Desire

-Vera Kratochvil, Publicdomainpictures.net

Beauty. over years of coevolution between humans and tulips, tulips have managed to captivate us through their vibrant colors and eye-soothing shapes. They ensure their survival as a species by aesthetically pleasing the gardeners which plant them.

-Petr Kratochvil Publicdomainpictures.net

Sweetness. The apple knows just what we want, that crispy, sweet, juicy taste. If the apple ever decided to evolve into something bitter, then the species will no doubt be in danger as we stop planting it.

-Junior Libby, Publicdomainpictures.net

Intoxication. Joints, doobies, bongs, hash brownies, you name it...Weed maintained its survival in the world by providing school boys a chance to "fit in" and drug dealers a source of income. Not only is it easy to grow, its easy to smoke too.



-Charles Rondeau, Publicdomainpictures.net

Control. The potato species will live on forever as it has evolved its way into the staple diet of a human being. Being high-yielding, easy-to-plant and delicious, the potato enjoys the benefits of being considered the prime food source of the world's dominant specie. 

The Great Steppes, Part II

STILL IN CHARACTER


A wise man once asked our people what would happen if the great steppes in which we live in gets struck by a severe disaster. We responded that the Mongolian people were able to conquer the Chinese Dynasty Empires,we were not afraid of some petty natural disasters...Unless when we're talking about zuds, or better known as blizzards.

The Mongolian people are nomadic herdsman, we rely on cattle, goats and sheeps to provide us with food, clothing and shelter. A village's strength is determined upon the health and numbers of its cattle. A zud is basically a severe and extremely harsh winter, with a few different types of zud that could each wreck serious havoc on the ecosystem of the steppes.

During heavy snowfall, the pastures get covered with snow and grazing animals are unable to reach the food source, and will starve to death. On more extreme temperature levels, the terrain gets covered in a sheet of ice from the blizzards and cattle is unable to go uphill to find possible food sources.It is also possible that the ice formed will be so hard that it shields animals from eating.There has also been cases of an extremely cold, but dry winter, which is the most dangerous as humidity level rises and grass will simply perish. When we are unfortunate enough to have zud occur during the mating season of our cattle, a tribe could possible face a decimation of their entire herd, as new-borns will die immediately from the cold and lack of food.

Small animals such as rodents, rabbits and snakes are able to hibernate through the winter, and are thus unaffected by harsh winters.

Overall, the biome of the steppes will change from a cool, desolate grassland into a stormy and frozen wasteland.

The Biome of the Great Steppes

Journals of a Mongolian Scout

(Translated from Uyghur script by Sean Yang)

Year 1216

Introduction

My lord, Temujin, has changed his name to Genghis Khan. The first Khan of mongolia, the first king to unite the plains of our great steppe under the banner of the Mongol Empire. and create the ruthless Mongolian horde.Under the pretense of "finding greener pastures for our herd" we have pillaged and quite literally swept across the entire Eurasia. Our cavalry have ridden as far as the steppe can go, and our arrows have plunged into skulls of all races.

On my latest excursion versus the Kara-Kitan Khanate,a enemy archer maimed my beloved horse in the leg, I subsequently fell off and injured my leg. Usually, the Mongolian Horde leaves the stragglers and the unfit behind for the mountain lions, but I was one of the few men that could read and write. Therefore, I am tasked by my great majesty to record the environment and note down everything about the steppe's climate and biome. A menial and trivial task for a man of my stature and martial prowess, but the Khan's wish is my command. Plus he is too busy planning the next raid and keeping his eight wives in check.

A painting of the supreme Khan, his beard is a lot longer now and looks better than that of Mr. Quick.

The Terrain and Climate

Our great steppe is known to the men we conquer as a temperate grassland. Ones who refuse to call it a steppe has already been buried alive. In the steppe, all we have is grass, a all important resource to feed our sheep herd.The Mongolians are a nomadic people, our land is too dry for crops and our herd needs more grass as food. During the time of our great Khan uniting Mongolia, clans would fight each other over petty acres of grass covered land. Now the Mongolian horde has conquered more grasslands than our herd will ever need! Travelers from other parts of the world have told me of steppes with different temperatures and rainfall, and even different types of grass. Perhaps one day our great Khan will conquer all of the steppes in the world. But in our Mongolian steppes, the air is dry and humid. During the summer, our sun can reach blistering temperatures of 104 F, and the gods show their discontent through frequent thunderstorms and fires which could devastate our herd's food source. We barely receive any rain during the dry seasons, and over the entire year, I have observed in a unused wash basin at home that the steppes have no more than 30 inches of rainfall a year. When our horde swept across the plains of Eurasia easily slaughtering all enemies in our way, I have noticed that the grass is lusher when we are closer to areas with trees, and little in number when close to the desert of our middle-eastern adversaries. Much to our rejoice, the great steppes have no trees! This allows our cavalry archers a clear line of shot against helpless villagers fearing for their life. The winters mark a period of intense hardship for us soldiers. With no trees, the winds howl with the sound of a dying fox and so strong that it blew our tents apart. Our coldest times were marked to be -40 F, and there has been days where our tents would collapse from the weight of the snow overnight. Our life on the steppes is hard, we dig deep into the ground for our water and our men learn to fight without rations for several days. But the Mongolians are a strong and tough empire, and our ecosystem has only made us fearless in the face of our enemies. Sometimes, when the enemy enters our steppes, they note down the giant mountains of skulls that is also part of our natural landscape.

Our strategist have devised a temperature graph over a year so that our troops can better prepare for the upcoming weathers.

The rainfall of our steppes vary in different times, we tend to cure our meat and stockpile food when the low rainfall times come since our herd may not find grass.

A painting of our steppes by our artist, notice how we have no clouds, which is why we freeze during the winter.

The Plants

The harsh climates of the steppes stops our grasses from growing too long, but after our horde has charged through vast plains of steppes we have never though existed, I have recorded down many types of different grass found in our conquered lands. We have the fringed sagebrush, milk vetch, sweet vernal, rhubarb and even tumbleweeds. Unfortunately, due to our rainfall, our grass never grows only longer than 1 and a half inch.

Milk Vetch

Fringed Sagebrush

Tumbleweeds!

Animals

The only wild life of great concern to our people are the horses. My own horse was caught by myself when I was at the age of 6. I jumped onto the toughest mustang I have ever seen near our village and managed to subdue it without getting flung off. Antelopes are also common, and they graze our precious grass which we need for our herd, so we hunt and kill them whenever we find one. There are also numerous types of burrowing animals digging deep into our soil, rabbits, squirrels and ferrets are all eaten whenever they are caught.Finally, the most dangerous animal which lives in our plains is the rare lynx cat. There was a tale of a lynx pummeling an entire group of adventurous young boys. Our great leader Genghis Khan keeps one as his pet. The falcons and eagles soar high up in the sky, and are used as target practice for the most skilled of archers. There are many more small lizards and insects, and mainly serve as food for the birds.

The lynx

The iconic Saiga Antelope

My son had one of these as his pet, our family ate it during the winter when we were out of food.

The Food Chain

The grass serves as the primary producer for all life in our steppes.

We have forgotten to put "enemy villagers" as a primary food source for our soldiers.

The plants in the steppes have deeper and stronger roots to protect against the wind and to find water easier. The plants are much like those of the desert. The symbiotic relationship of our steppe biome is parasitism. When one species becomes weak, the other becomes more powerful and dominant.

Websites Visited (Pictures too)

The foodwebb, 

http://ecoplexity.org/model_collection

Biogeographical Process,

http://clasfaculty.ucdenver.edu/callen/1202/Landscapes/Biogeog/Biogeog.html

Climate/Temperature of Biomes, 

http://earthobservatory.nasa.gov/Experiments/Biome/graphs.php#grassland

The Steppe Biome

http://www.blueplanetbiomes.org/steppe_plant_page.htm

Animal Behavior Lab (Pill Bugs)

Animal Behavior Lab Done with Pill Bugs (Rollie Pollies)

Abstract:

To order to gain a better understanding of animal behavior, we have conducted a lab in our biology class using pill bugs. To observe how pill bugs reacts to different environments, my partner and I did experiments involving pill bugs' preference to moisture, scent and terrain. In each experiment we used 10 pill bugs placed in a behavior chamber covered with filter paper. The behavior chamber is divided into two areas with different properties. For our first experiment (moisture), we drenched one filter paper with water and left the other dry, and after recording the pill bugs' movement for 7 minutes at 30 second intervals, we observed that the pill bugs prefered the wet environment. Our second experiment was conducted in the same way except instead of water we drenched the filter paper with honey. Our results did not show pill bug's reaction to honey/sugar. For our final experiment we put large beads simulating a rocky environment in one chamber while the other remained dry filter paper, we saw a large movement of pill bugs from the paper to the beads, thus demonstrating a preference for rocky terrain of pill bugs.

Background:

Animal behavior (ethology) is the way in which something acts or reacts by itself or to other beings. In ethology, questions regarding behavior is categorized into 2 types, proximate questions and ultimate questions. For example, when we study a bird singing, a proximate question would be "How did the bird tell when it's time to sing?" and a ultimate question would be "Why does the bird sing?" A fixed action pattern is a natural, innate behavior in a animal that does not change and not taught by others. For example, when a angry biology teacher smacks a disruptive student in the arm, the student instinctively and naturally cries out in pain and defiance (maybe not the latter in some countries); the reaction is innate since no one has explicitly taught the student to cry in pain when hit. Imprint is a type of behavior that is a combination of both innate and learned, it constitutes to an animal's response to a certain stimulus. In young geese for example, the ducklings will imprint on the behavior and characteristics of its surroundings, no matter the species. This can cause bizarre cases of young geese imprinting on humans or other non-predatory species. A proximate explanation could be that young geese are born incredibly clueless and need something to imitate, while a ultimate explanation could be that young geese lacks the intelligence to develop and learn basic behaviors on its own. In ethology, the response to a stimuli can also be categorized into kinesis and taxis. Kinesis is when animals respond randomly to a stimuli while taxis is specifically. For example, when pill bugs realize they are in a unsuitable environment, they will randomly move around until they find a better environment, for taxis, when the light were just turned on in a dark surrounding, insects and moths will immediately flock to it, it doesn't randomly find a place with light. Another distinction of animal reaction is classical and operant conditioning. Classical conditional is a involuntary/uncontrolled response to a external stimuli, such as a biology student screaming in pain as a teacher hits him. A operant response is a voluntary response in order to gain something, such as a student quickly wakes up when the teacher talks about the upcoming test, in order to achieve a passing grade.

Hypothesis:

Independent variable: Honey, water and beads

Dependent variable: Amount of pill bugs in each chamber

Moisture Lab:

If the pill bug prefers wet environments to dry environments, then pill bugs should undergo kinesis in the behavior chambers until they reach the other moist chamber, to which they should stay.

Honey Lab:

If the pill bug can detect scent, then pill bugs should undergo kinesis in the behavior chambers until they reach the honey covered chamber because bugs like sugar.

Terrain Lab:

If the pill bug hold preference over terrain, then pill bugs should undergo kinesis in the behavior chambers until they reach the bead covered chamber because they should be able to detect the terrain through sense of touch.

Materials:

10 pill bugs

1 behavior chamber
6 pieces of filter paper (for all 3 parts)
Brushes for moving bugs
Timer/clock
5 ml water
5 ml honey
30 small beads

Procedure:

Place 10 pill bugs into a behavior chamber covered with 2 pieces of filter paper, always leave one of the filter papers dry and untainted (control). The other piece of filter paper should be covered with water, honey or beads depending on the lab. Start the timer and cover the behavior chamber so light does not shine on the bugs. Every 30 seconds lift the cover and record down the amount of pill bugs in each side of  the chamber, continue on for 7 minutes with each lab.

Results:

Moisture lab:

Time (minutes)	# in Dry Chamber	# in moist chamber
0	2	8
0.5	2	8
1	2	8
1.5	2	8
2	1	9
2.5	1	9
3	0	10
3.5	0	10
4	0	10
4.5	0	10
5	0	10
5.5	0	10
6	0	10
6.5	0	10
7	0	10

Our results correlate with our hypothesis, showing that pill bugs do indeed prefer wet environments over dry environments.

Honey Lab

Time (minutes)	# in dry chamber	# in honey chamber
0	2	8
0.5	2	8
1	2	8
1.5	2	8
2	3	7
2.5	3	7
3	3	7
3.5	2	8
4	3	7
4.5	2	8
5	1	9
5.5	3	7
6	4	6
6.5	4	6
7	3	7

My partner and I's hypothesis wasn't entirely correct, we believe that the pill bugs had no reaction to the presence of sugar around him as the data shows the pill bugs movement as random and erratic.

Terrain Lab

Time (minutes)	# in dry chamber	# in bead chamber
0	0	10
0.5	1	9
1	3	7
1.5	5	5
2	6	4
2.5	5	5
3	7	3
3.5	6	4
4	7	3
4.5	9	1
5	10	0
5.5	9	1
6	10	0
6.5	8	2
7	9	1

Our lab results showed a great movement of pill bugs from the dry flat surface to the rocky bead covered chamber, this shows that pill bugs have a strong preference for uneven terrain as they quickly settled when they reached the beads,

Conclusion

Our results for our experiment showed that pill bugs preferred wet, uneven environments, and has no affinity to sugar or scent due to the amount of pill bugs staying dormant in their preferred environments, or undergoing kinesis in attempt to find a suitable environment. Possible error analysis in this experiment could be the amount of pill bugs present is not enough to provide reliable data, or the amount of time the pill bugs are left in their chambers isn't enough for them to demonstrate their behavior.

Works Cited

Emily Leck, "Chapter 51: Study Questions - Behavioral Ecology." Quizlet.com

Immune System Quiz

How the Immune System...


Provides an immediate and nonspecific immune response...

The nonspecific or innate immune system is the first line of defense against an foreign invader into your body, and its first response to infection is inflammation. The nonspecific immune system doesn't have a specific defense for different pathogen invaders, rather, it is like a immediate "emergency lock-down" button that always responds quickly and always in the same, generic way. When an invading pathogen damages a cell, the cell releases information to the body and we form a barrier to stop further spread of the infection, and also repair anything damaged. There are many white blood cells present in the innate immune system line of defense...
Some key cells would be phagocytes and macrophages, which envelope pathogens in their endosomes and move them to the lysosome, which has enzymes and acids which will destroy the pathogen.
Dendritic Cells are also very important since they reside at the skin, and stop bacteria from simply waltzing through to your body wrecking havoc.
Mast cells protect against and heal wounds in the body also.

A simple diagram of the macrophage, notice how it has receptors that trigger it to engulf pathogens when it comes in contact with invaders.

A country at War - A Dystopian Short Story By Sean Yang

To think of a real life scenario...Imagine a country that has suddenly been invaded by foreign enemies. The dendritic cells, or the border patrols, in this case, would try to stop as many bad guys as possible. When the enemies broke through and integrated themselves into the ranks of the country, the whole country enters systematic lock-down (inflammation) and the secret police (phagocytes and macrophages) begins to hunt down the invaders and escort them in a van (endosomes) to the execution range where they will be killed (lysosomes). Because the invaders have already destroyed parts of the country, aid groups (mast cells) are sent out to reconstruct the city and heal injured people (cells).
Continued in the next section...

Activates T and B cells in response to an infection

T and B lymphocytes are all made in the bone marrow. B cells simply lie dormant until a antigen attaches to it, which then causes it to trigger and eats the antigen. After the B cell eats its antigen, it leaves parts of the antigen stuck to his MHC (major histocompatibility complex) molecules which are unique to each B cell.
The T cell will then look for B cells that have already digested antigens and have antigen parts. The T cells will then move in to support the B cell by producing cytokines which could help the B cell to become antibodies. The T cells themselves are created from the thymus and also switch forms to have many functions. Some continue to produce cytokine that attract macrophages and other white blood cells, and some track down infected cells.

2 good diagrams that really explains the relationship between T and B cells well

Now...ongoing with my scenario...its a little graphic but it really captures the essence of T and B cells
With the invaders now present in the borders of the country, the government realized that it needs to mobilize the national army. The government sent convoys of troops (B cells) around the country and set up many ambushes to take out the invaders. When a convoy captures a group of invaders (antigens), the troops chop off the invaders' heads (antigen fragments) and stick it on a unique pike (MHC molecules) so that the new eager army recruits (T cells) can see. The new recruits, invigorated by the presence of soldiers who just decapitated the enemy and heads on pikes, start to work double time on creating new weapons (cytokines) for the army. The new weapons (cytokines) will be used to train more recruits (T cells). Experienced recruits also get some field work such as providing support on the war zone to the secret police (macrophages) or track down invaders themselves.
Continued in the next section...

Responds to later exposure to the same infectious agent


A simple graph that illustrates how the white blood cells in your body learn to fight off similar antigens quickly. As you can see above, the second exposure of antigen A received a far more effective antibody response.

When pathogens invade into a body, not all B cells will be triggered by an encounter with an antigen, and so the rest of the excess "naive" B cells will undergo clonal selection to form clusters of cells that are specific for fighting against the antigen. Although most of the cloned B cells will differentiate, some become important memory B cells which can survive for ten years. The memory B cells have a specific amino acid sequence that binds well to the antigen called the paratope. So when the same antigen invades again, the memory B cells with the accustomed paratopes will kill the antigens much much faster than the first encounter. Memory T cells also work this way and could be used to fight cancer; if they are able to recognize foreign invaders such as cancer cells, they will head out and kill them.

A picture showing the naive B cell becoming a memory B cell

The war is over, the country is devastated, but intact. Remaining soldiers that have not been deployed or encountered enemies (B cells) are put through a special training program (clonal selection) to become skilled, experienced and specialized fighters (memory B cells) to counter a possible future invasion. The government have also developed special weapons (paratope) for the special forces that causes immense harm to the enemy should they come again. Leftover recruits can also attend this intense training regimen (T memory cells). The government has also staged multiple harmless drills that simulate an invasion (vaccines) in order to get the army prepared for a possible future invasion.

Distinguishes Self From Non-self

Our antibodies belong to our body, and they know that also. To prevent our own cells from starting an outright civil war with each other, our cells have distinctive epitopes (shapes) that causes the cells to identify with each other. When pathogens invade, the antigens all have different epitopes and therefore our white blood cells are able to determine that they are of a foreign source and begin to attack. When a foreign antigen is discovered, a antibody latches itself onto it and activates the phargocytes to eat it. Allergy is a result of the body's immune system reacting to a seeming harmless substance, such as the smell of a freshly printed Biology test or cat hair. When allergy happens, there aren't any antigens; rather, they are called allergens.
A picture showing antibodies (the Y shapes) attaching themselves to specific epitopes.

With the numerous cases of friendly fire and the mistreatment of citizens by the army during the war, the government has issued flags to everyone belonging to the country and also told all the people (cells) to raise their flags when in contact with others. There has still been numerous cases of friendly fire when soldiers accidentally set their flags on fire when attempting to light their cigarettes.

The End 

Talk About Breasts! Milk!

LINK

Transcript

Oxytocin and Prolactin are two hormones that have very identical functions, while both hormones do have some exclusive functions, such as oxytocin stimulating the uterus contraction during labor childbirth, Oxytocin and Prolactin are both concerned with breast milk. Prolactin is responsible for the triggering the production of milk proteins, or breast milk, while oxytocin is responsible for activating “milk let down” when suckling. For the purpose of this recording, I will only be focusing on oxytocin and prolactin’s roles in breast-feeding. I’ll begin first by explaining prolactin’s qualities.

The most predominant structure of prolactin that is present in the human body is a single-chain polypeptide with 198 amino acids. Prolactin is mostly produced in the anterior pituitary gland, but also produced in breasts. The function of prolactin that I will be focusing on will be stimulating the mammary glands to produce milk; the other function of prolactin is sexual gratification after sexual acts, but I won’t be focusing on that. Prolactin is regulated by the dopaminergic system and levels of prolactin are proportional to the level of estrogen in females, and testosterones in males. In females, estrogen inhibits prolactins on its milk production; it is only the sudden drop of estrogen after child-birth that allows mothers to produce breast milk for their babies. When a baby starts suckling on his mother’s breasts, prolactin is secreted and released into circulation to bind to the mammary epithelial cell receptors in the mammary glands of the mother, which stimulates milk to be produced in a matter of few minutes. When a mother does not breast feed, prolactin levels will return to normal after 7 days, and cause her to stop producing milk, therefore, mothers will usually breast feed multiple times a day to stimulate prolactin production and produce a lot of milk.

Onto oxytocin…Oxytocin is a peptide of 9 amino acids produced in the posterior pituitary glands. Unlike prolactin, which produces milk when stimulated by a baby suckling, oxytocin is responsible for releasing milk from the breasts. When undergoing childbirth or breast feeding, oxytocin is produced and released to the receptors located in the myoepithelial cell of the mammary gland; this stimulates multiple actions. In labor, uterus contractions occur which allows a smoother childbirth, while in breastfeeding, oxytocin acts at the mammary glands allowing milk to be secreted from the nipples. Oxytocin levels also affect social behavior and some degree of sexual response.

Both oxytocin and prolactin are regulated in positive feedback, which is not too common in hormones. For example, during childbirth, when the baby is moving towards the vagina, pressure receptors within the cervix triggers the pituitary gland to produce oxytocin, which then binds to its receptors and cause uterus contraction. The same goes for the stimulation of prolactin and oxytocin production when a baby suckles during breastfeeding. The chemical pathways of both prolactin and oxytocin are neuroendocrines, since they undergo endocrine secretion and are triggered by nervous stimulation such as breastfeeding. Both hormones are lipid soluble hormones, since they belong to the endocrine system and diffuse into a cell to bind with receptors.

And that about concludes my talk about where breast milk comes from!

Cell Respiration Lab

Yeast Cell Respiration Lab

Group members: Sean Yang, Andrew Mao

Abstract
In order to understand the process of cell respiration and how temperatures could affect it, we have created a lab using the fungi yeast to observe the process of cell respiration under different temperatures.

Introduction
Cell respiration occurs in all living cells, and is the process in which organisms produce ATP energy from glucose, with byproducts of carbon dioxide and water. ATP is the energy which cells function upon. Yeast is a type of fungi which can respire only with the presence of oxygen and glucose. Under different environments, yeast will respire differently.

Glucose + Oxygen → Carbon Dioxide + Water

C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O

Hypothesis:
Due to increased molecular movement when under heat, it is likely that cell respiration of yeast will occur at a faster rate due to the fast movement of particles at high temperature.

Materials: Sugar, water, yeast, salt, scale + weighing paper, graduated cylinders, 3 thermometers, 3 airtight syringes, 3 test tubes, an ice box and a warm dry heating bath.

Procedure:

1. Obtain 3 separate set of measurements of 35ml water, 1g of sugar, 1g of yeast and 0.2g of salt.

2. Obtain 3 separate test tubes and mix all contents evenly into the 3 test tubes.

3. Stir up the contents in each test tube and let them all sit for 5 minutes.

4. This step must be done quickly and simultaneously: after 5 minutes, immediately put the airtight syringe over each test tube, make sure there are 2ml of air where the syringe is not losing any gas (airtight).

5. Quickly put each test tube at their locations: one out in the open, one in the ice box, and one in the heat bath.

6. Collect the change (reading minus 2ml) in ml of gas every 1 minute for a total of 5 minutes.

7. Stick thermometers into the ice box and the warm bath to note their temperature.

Safety

-The warm dry heating bath shouldn't be too hot (50 degrees), but don't stick any body parts in just in case.

-Yeast makes a disgusting smell after fermentation, keep away from nose, mouth, eyes and hopefully clothes.

-Test tubes are made of glass, be careful when shoving the syringe into the test tube, don't use too much force, you might shatter it in your hand.

Results

Conclusion
As the graph shows, CO2 produced by yeast cell respiration increases in a much faster rate when at warm temperature. At cold temperature, there is almost no CO2 formed as we believe the enzyme have denatured due to the cold. This is evidence to confirm our hypothesis that cell respiration occurs at a more rapid rate at higher temperatures, we believe that this is due to faster particle movement at higher temperatures.


Revision (2014/3/09):
After having my lab report checked up by my teacher, I realized I was lacking in many parts...so below I will provide additional information to explain the phenomenon that has occured in this lab.

Background Information:
Cell respiration is a complicated process occurring in a cells cytoplasm and mitochondria where cells utilize glucose to produce ATP energy in order to function. Cell respiration has numerous steps and each small process is powered by a different type of enzyme. We have learned in class that enzymes are "catalysts" for the cell and lower activation energy/speed up each small step in cell respiration. We have also learned that when under abnormal temperatures (every enzyme has an ideal temperature) enzymes will denaturalize and fail to achieve their catalyst effects. Our yeast cell respiration lab will test the effectiveness of enzymes under different temperatures by monitoring the amount of CO2 produced when yeast cells go through cell respiration.

Hypothesis rewrite:
If the temperature of the environment in which the yeast is in increases, then we can expect a faster rate of cell respiration and faster rate of CO2 emission; this is because yeast molecules under heat will increase their molecular movement and enzymes will catalyze a chemical reaction at a faster rate.

Conclusion Rewrite:
Although we have not tested a large enough range of temperatures to find the ideal temperature for yeast cell enzymes to undergo cell respiration, we have discovered through our data and graph that the warmer the temperature, the more effective the enzyme and thus the more CO2 produced from respiration. We have proven our hypothesis to be correct as the higher the temperature, the more CO2 we have gotten and the faster rate at which enzymes operate due to increased molecular movement speed.