«Cells need energy to do work to carry out metabolic processes that keep them alive and functioning. This energy is stored in the form of ATP, which stands for adenosine triphosphate. All plant and animal cells use a process known as cellular...» Document abstract
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Language : english
biology
case study
date published
23/10/2007
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SummaryCells need energy to do work to carry out metabolic processes that keep them alive and functioning. This energy is stored in the form of ATP, which stands for adenosine triphosphate. All plant and animal cells use a process known as cellular respiration to make ATP from carbohydrates. Plant cells also have a process known as photosynthesis that they use to fixate carbon into carbohydrates using energy from the sun. However, even in plant cells, the most important energy contribution is made by cellular respiration, since ATP formed during photosynthesis is used primarily to fixate the carbon atoms for later use in glycolysis (a step of cellular respiration). Cellular respiration can either be carried out aerobically (in the presence of oxygen) or anaerobically (in the absence of oxygen) (Miyazaki, 85). This lab is concerned with testing the anaerobic pathway, namely alcohol fermentation.
Table of Contents- Alcohol fermentation occurs after glycolysis, instead of the Krebs cycle.
- The first experiment involved setting up a standard protocol, so that we could become familiar with the apparatus that measures the water displacement by CO2 and simultaneously see the affect of yeast concentration on fermentation rate.
- Following the conclusion of the standard protocol, we set up another experiment using the same set up.
- With respect to the standard protocol experiment, there is one main reason why the data turned out as it did.
- In conclusion, according to our experiment, fermentation is greatly affected by yeast concentration and pH levels.
«Bacterial transformation is the transforming of a bacterial cell using plasmids spliced with various types of DNA from other cells (Miyazaki, 201). Instead of a nucleus with chromosomes, bacterial cells have one large circular chromosome in their...» Document abstract
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medical studies
case study
date published
23/10/2007
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SummaryBacterial transformation is the transforming of a bacterial cell using plasmids spliced with various types of DNA from other cells (Miyazaki, 201). Instead of a nucleus with chromosomes, bacterial cells have one large circular chromosome in their cell. They also have much smaller rings of DNA throughout their cytosol. These smaller DNA rings are the plasmids which one can manipulate and introduce into cells for transformation to occur. (Miyazaki, 203)
One example of such a manipulated plasmid is the pGLO plasmid. This is the plasmid that we used in this lab. We introduced this plasmid into E. Coli bacteria using the heat shock method. This method involves placing the transformation mixture with the bacteria and the plasmid into ice and then into a hot water bath several times. We also made use of a CaCl2 solution which made the cell walls of the cells even more permeable to the plasmids.
One example of such a manipulated plasmid is the pGLO plasmid. This is the plasmid that we used in this lab. We introduced this plasmid into E. Coli bacteria using the heat shock method. This method involves placing the transformation mixture with the bacteria and the plasmid into ice and then into a hot water bath several times. We also made use of a CaCl2 solution which made the cell walls of the cells even more permeable to the plasmids.
Table of Contents- One example of such a manipulated plasmid is the pGLO plasmid. This is the plasmid that we used in this lab.
- The hypothesis was that bacteria on a plate with arabinose would fluoresce if they had been transformed, and that bacteria on a plate with ampicillin would still grow if they were transformed.
- First, we observed the plasmid mixture under a UV light, and noted that it did not fluoresce.
- The plate labeled DNA+/LB/amp/ara had many white colonies on it.
- The DNA-/LB/amp plate was the most puzzling one.
- In conclusion, our experiment mostly confirmed our hypotheses and predictions.
«Water comprises a very large part of an organism’s body. The delicate balances within the systems of an organism involve the concentrations of, to name a few, Na+, K+, Cl-, and Ca2+ salts (Dilger and Collins, p. 9). There are two types of fluids...» Document abstract
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Language : english
medical studies
case study
date published
23/10/2007
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SummaryWater comprises a very large part of an organism’s body. The delicate balances within the systems of an organism involve the concentrations of, to name a few, Na+, K+, Cl-, and Ca2+ salts (Dilger and Collins, p. 9). There are two types of fluids within organisms; the ICF (intracellular fluid) and ECF (Extracellular fluids). Every organism regulates the tonicity of the ICF. However, the ECF can be regulated or non-regulated. Organisms fall into two categories based on this distinction. These categories are the osmoconformers and the osmoregulators (Dilger and Collins, p.9). Osmoregulators have special mechanisms to keep their BFOC (Body fluid osmotic concentration) constant, independent of the EOC (environmental osmotic concentration). Osmoconformers, on the other hand, have a BFOC that is directly related to the EOC ( Dilger and Collins, p.9).
Table of Contents- The two organisms that we studied in the lab were the sand worms Nereis sp. and the hard clams, Mercenaria mercenaria.
- To carry out this experiment, we used three different concentrations of artificial salt water using a mixture of 'Instant Ocean' and water.
- The worms weight change shows that in a less salty solution, they gain weight.
- At the conclusion of this lab, there are some confirmations of the hypothesis and some discrepancies.
- In general, organisms could use other osmoregulating devices such as protonephridia, metanephridia, malphighian tubules, and the kidneys.
«One of the most important organs in the body is the heart. Of course, this organ is of great importance not only in humans but in all vertebrates. Blood, which carries nutrients, oxygen, and wastes from organ to organ within the body is pumped by...» Document abstract
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Language : english
medical studies
case study
date published
23/10/2007
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level : General public
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SummaryOne of the most important organs in the body is the heart. Of course, this organ is of great importance not only in humans but in all vertebrates. Blood, which carries nutrients, oxygen, and wastes from organ to organ within the body is pumped by the heart. Without the heart’s pumping action, blood would simply remain stagnant within the vessels of the body, and any vertebrate in this condition would die off very quickly.
Table of Contents- While the heart is essential to all vertebrates alike, it is important to note that there are some stark distinctions between the hearts of different vertebrates.
- Although the heart is able to initiate its own action potential and make itself beat, there are sympathetic and parasympathetic neurons that innervate it.
- As compared to the control, adding epinephrine sped up heart rate but, according to the readings, decreased contractile strength.
«Our experiment was concerned with the reflex response in humans, and how it compares to a voluntary neural pathway as well as how it is enhanced by what is known as the Jendrassik Maneuver. Our hypothesis was that the reflex response would be faster...» Document abstract
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Language : english
medical studies
case study
date published
23/10/2007
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level : General public
requested 19 times
SummaryOur experiment was concerned with the reflex response in humans, and how it compares to a voluntary neural pathway as well as how it is enhanced by what is known as the Jendrassik Maneuver. Our hypothesis was that the reflex response would be faster than the voluntary response, and that with the Jendrassik maneuver, the reflex would be even more responsive. We predicted the latency to be lower for the reflex as compared to the voluntary response, and the amplitude to be higher for the reflex with the Jendrassik maneuver as compared to the reflex on its own. We conducted this experiment with the help of an apparatus that measured the angle during leg movement after the reflex. Specifically, flexion of the quadriceps (the reflex response) would cause the leg to kick out. The apparatus was basically two pieces of plastic connected to each other at a joint. One piece was attached to the calf and the other to the thigh. When the leg kicked out, the angle at which the two pieces of plastic connected changed, and the magnitude of change was recorded on a computer hooked up to the device. It would serve well to understand some background information about the neuron, neurotransmitters and their receptors, excitatory/inhibitory reflexes, and involuntary reflexes.
Table of Contents- The neuron consists of the soma (cell body), axon, dendrites, and in some cases myelin sheaths.
- The knee jerk reflex tested in this experiment was one such involuntary movement.
- Materials and Methods
- Results
- The average latency for the reflex knee jerk was .32 seconds.
- Discussion
- Our results were consistent with our hypothesis and our predictions.
- As for the voluntary knee jerk vs. the reflex knee jerk, our predictions also held up.
«The process of genetic transformation is an important tool used in biotechnology. It has been used in agriculture to create plants that are resistant to different kinds of conditions. In medicine it is being used to try and create bacteria that...» Document abstract
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Language : english
medical studies
case study
date published
09/10/2007
review : not yet assessed
level : General public
requested 5 times
SummaryThe process of genetic transformation is an important tool used in biotechnology. It has been used in agriculture to create plants that are resistant to different kinds of conditions. In medicine it is being used to try and create bacteria that produce insulin which can be used to treat diabetes. Transformation can also e used to give bacteria the traits to digest oil, which then can be used to clean up oil spills. In nature transformation also accurse by itself, when suddenly bacteria become resistant to antibiotics, when they are introduced to it over and over. This happens because bacteria naturally share their DNA with each other which lets them adapt to the environment.
Table of Contents- The process of genetic transformation is an important tool used in biotechnology.
- In our experiments we had several variables that were available because of the pGLo plasmid.
- Our group obtained two Falcon tubes which we labeled +DNA for one and the other –DNA.
- The –DNA agar plates contained bacteria that were not introduced to the pGLo plasmids.
- The plate which had the arabinase had 85% of the colonies glowing under a UV light.
- Based on what we have done so far other experiments might be interesting to conduct based on similar settings.
«Many people are already indirectly familiar with the processes of fermentation, from the baker to the body builder. The baker, when baking his bread, adds yeasts that produces CO2, which makes the bread rise. Alcohol is also produced during this...» Document abstract
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Language : english
biology
case study
date published
09/10/2007
review : not yet assessed
level : General public
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SummaryMany people are already indirectly familiar with the processes of fermentation, from the baker to the body builder. The baker, when baking his bread, adds yeasts that produces CO2, which makes the bread rise. Alcohol is also produced during this fermentation but it quickly evaporates during the baking process. When the body builder is exercising too hard your muscles need extra energy which they obtain from lactic cid fermentation and the cramps that are felt are from the access lactic acid that is the byproduct. Moreover, anaerobic respiration is also carried out by some types of fungi and bacteria when the supply of oxygen is not enough for regular cellular respiration.
Table of Contents- Introduction
- Both these processes start off with glycolysis, a process which is used in anaerobic environments, and end with the production of ATP.
- Based on the fact that the ratio of CO2 to ATP produced is 1:1, we can test the rate of ATP indirectly by looking at the rate of CO2.
- Methods
- Results
- Discussion
«As living things, we are highly sensitive to changes in our environment; this doesn’t only mean changes outside our body, but changes from within also. For the cells in our bodies to function properly a certain temperature and pH has to be...» Document abstract
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Language : english
physics & chemistry
case study
date published
09/10/2007
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level : General public
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SummaryAs living things, we are highly sensitive to changes in our environment; this doesn’t only mean changes outside our body, but changes from within also. For the cells in our bodies to function properly a certain temperature and pH has to be maintained. Even a slight change in pH inside our bodies can cause serious repercussions. Most of the fluids in our bodies range in pH from 6 to 8. Our body has buffers that maintain the pH of blood very close to 7.4 and we can not survive for more than a few minutes even the blood pH has changed slightly. Nature, to make sure homeostasis is maintained, has provided certain molecules that act as buffers. Buffers are molecules that absorb or release protons depending if the solution becomes more acidic (absorbs protons) or more basic (releases protons) (Miyazaki 4).
Table of Contents- Introduction
- A type of buffer that is used in many living system is the amino acid.
- Methods
- Results
- As predicted sodium chloride did not have any buffering capabilities.
«Reflexes are the body’s involuntary responses to various stimuli. They are controlled in large part by the human nervous system which has three main functions: sensory input, integration, and motor output. Sensory input is due to sensory receptors...» Document abstract
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Language : english
medical studies
case study
date published
09/10/2007
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level : General public
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Summary Reflexes are the body’s involuntary responses to various stimuli. They are controlled in large part by the human nervous system which has three main functions: sensory input, integration, and motor output. Sensory input is due to sensory receptors throughout the body collecting information about one’s external surroundings and internal environment, and relaying them to various information centers. A sensory receptor recognizes some form of stimulus in the external or internal environment and responds by creating graded potentials or action potentials in the cell or in the cell adjacent to it. These action potentials consequently lead to integration. Integration is mainly carried out within the Central Nervous System, which consists of the brain and spinal cord in humans. (Campbell, 1024) Motor output is what occurs when the central nervous system makes sense of the sensory input due to integration, and sends information to effector cells in the body. Effector cells are the gland cells or muscle cells that make sure the body’s responses to certain stimuli are carried out. (Campbell, 1024) Nerves conduct these signals. Specifically speaking, the particular nerves that relay the motor and sensory information from the central nervous system jointly make up what is called the peripheral nervous system.
Table of Contents- Introduction
- Reflexes are the body's involuntary responses to various stimuli.
- Neurons are the main unit of the nervous system.
- The whole process of a knee jerk reflex requires only three neurons.
- Results
- Table 2 shows the results of the first test, during which we delivered a tap to the patellar tendon with the hammer.
- In the third experiment on a human subject, we incorporated the Jendrassik maneuver.
- Two important terms to define are flexion and extension.
- Discussion
- Even though sources of error do exist, our results closely mimic our hypothesis.
- In the third experiment, we combined the use of the Jendrassik maneuver with the involuntary knee jerk reflex, once again striking the patellar tendon directly with the hammer.
- Negative feedback is the process where a change in a physiological variable triggers a response that counteracts the initial reaction.
«Ever since Microsoft released its newest installment in the Windows operating system line-up, titled Vista, computer users around the globe have been having mixed feelings about the highly anticipated product. Since its release in November of 2006,...» Document abstract
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2 word format
Language : english
computer science
school essay
date published
05/10/2007
review : not yet assessed
level : General public
requested 10 times
SummaryEver since Microsoft released its newest installment in the Windows operating system line-up, titled Vista, computer users around the globe have been having mixed feelings about the highly anticipated product. Since its release in November of 2006, Vista has been slowly attempting to dominate the operating system market. The lush graphical elements (the use of DirectX 10) included in Vista, alone, have won over a large customer base. On the other side of the spectrum, countless customers are less than satisfied by the shady performance of the highly coveted operating system.
Table of Contents- Ever since Microsoft released its newest installment in the Windows operating system line-up, titled Vista, computer users around the globe have been having mixed feelings about the highly anticipated product.
- The first missing feature listed is font composition.
- The next missing feature that was promised is easier networking capabilities.
- Other missing features include fewer reboots and faster startups.
- The final missing feature mentioned is improved stability.
- This presentation board discussed a visual project which attempted to prove that classic film styles can be entertaining and relevant.
- This method is invaluable in the world of advertising and information technology.
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