AimTo calculate the surface area of the fish gas exchange surface, and to understand how the respiratory system of a bony fish. Apparatus
ProcedureIn order to accurately calculate the surface area of the gas exchange surface, we need to separate one whole gill arch from the rest of the head. I started off with just the head and so first decided to remove the oviculum of the fish, I did this the gill arches were revealed. From then on I was able to see the gill arches inside the head. I then proceeded to remove one of them from the head of the fish utilizing the forceps, scissors and the scalpel. This took a long time as the arch was firmly attached to the inside of the head. Then I proceeded to make the appropriate measurements. First I took note of how many filaments were on 1cm of the gill arch (X). Then I measured using a ruler the length of the gill arch (Y). Finally I measured the length of one singly filament (Z). Finally I used this equation to get my surface area X x Z x 2 x Y x 8 The reasoning behind this is as follows. I needed to multiply the number of filaments on a 1cm stretch of gill by the length of a single filament to get the length of the filaments on 1cm. Also filaments have two sides so that number must be doubled. Then I must multiply that number by the length of the gill arch to get the total length of the filaments on the whole gill arch, and then that number by 8 to get the total surface area, as there are 8 arches Results 12 x 2 x 2 x 7 x 8 = 2688 cm2
What this shows is the immense surface area of the fish’s respiratory system which is key to allowing a high rate of diffusion. This is proven as according to Fick’s law: Surface area x difference in concentration/ thickness of diffusion surface This is required as diffusion of gases in water is a slow process and if water passes over the gills too quickly it limits the amount volume of oxygen and carbon exchanged. Thus by having a large surface area, the fish has more opportunity for gas exchange to happen.
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A new study published in Cell magazine suggests the degenerative disease could be caused by microbes that inhabit the gut. Researchers used mice genetically programmed to develop Parkinson's as they produced very high levels of the protein alpha-synuclein which is associated with damage in the brains of Parkinson's patients. However the scientists dicovered that only the mice with this specific bacteria in their stomachs developed the disease, the others mice remianed healthy Further tests showed transplanting bacteria from Parkinson's patients to mice led to more symptoms than bacteria taken from healthy people. The scientists believe this bacteria releases chemicals that cause parts of the brain to become overactive.The bacteria can break down fibre into short-chain fatty acids. It is belived that it is these cells that cause the immune cells within our brains to cause the excessive damage. Dr Sarkis Mazmanian said "We have discovered for the first time a biological link between the gut microbiome and Parkinson's disease." What could this mean for the world of medicine? Well if it is indeed caused by this bacteria in the gut, drug companies could develop mdeication to combat and kill these microbes and we could eradicate the disease as we know it. http://www.bbc.co.uk/news/health-38173287 The microglia activated by the bacteria in the gut
A new vaccine against the HIV virus is being tested in South Africa, which scientists will hope will be our cure to the aids virus.
It is being led by South Africa's Glenda Gray, a university research professor and head of South Africa's Medical Research Council. The study is incorporating 5,400 sexualy active men and women in the country. In my personal opinion I am sceptical about the quality of this vaccine as so far previous tests have only shown a 30% protection rate, which is not a very promising start. http://www.bbc.co.uk/news/world-africa-38157123 Yesterday we discussed the rising problem of the antibiotic crisis in the world currently. The problem essentially is that our excessive use of these antibiotics is causing new "spuper bugs" to develop and bacteria are becoming resistant to our antibiotics. This has the potential to become a problem on a mass extinction scale for the human race. Antibiotics are medicines that inhibit the growth or destroy foreign microorganisms in our body The problem occurs from the random mutations in the genes of the bacteria. Despite the rate of mutation being incredibly low, there are millions upon millions of bacteria cells in one colony, making the chances of mutation increase. There is then a chance that one of these mutations causes the bacteria to become resistant to the effects of the antibiotics. These then will survive while the others die, and continue to multiply so there are vast quantities of resistant bacteria. This process is accelerated by antibiotics. Our constant exposure to these drugs is causing selective pressure on the bacteria in our body, which means the bacteria that survive are more likely to be resistant. There is an increasing worldwide resistance to many of the antibiotics in our arsenal and now we only have a few types of antibiotics left which still remain effective. One such example are cephalosporins. The reason they are so effective compared to others is because they were retired a long time ago, due to some adverse side effects. However that meant the bacteria have had little recent exposure to them so they have no resistance. The NHS and private doctors and hospitals are as a result reluctant to hand these out and view them as a last ditch attempt to save a patient so as to minimise use. Diagram of a cephalosporin. However all these efforts are being thwarted by the agriculture industry. Over the last year the use of cephalosporins introduced to animals such as cattle and swine to combat bacterial infection has almost doubled. The bacteria is then further passed in to us in their meats and in their mil. It is also also passed into their faeces, and that is then used as fertilizer for crops we eat. This can cause many problems including increasing our exposure which would cause more resistance, increasing exposure to our animal population placing them at risk as well as our crops facing the same threat. Another way the problem of resistance is being increased is due to our constant exposure to normal antibiotics regularly, legally or illegally. We are taking in too many antibiotics and as a result we are causing our standard drugs to become ineffective. Finally just my thoughts on a solution. I think we should outright ban the use of more powerful antibiotics in the agriculture industry and heavily manage and restrict the use of regular antibiotics to help reduce that risk. This I think will help combat the risk of o=involuntary overexposure. Then finally I would invest money to help develop a new method of combating illnesses and once that is developed regulate that aswell so as to not create the same problem again. The main way we would do this is to keep patients under the observations of a trained medical professional while using these new methods and try to only introduce intravenously to prevent self medication.
Last Thursday we took a trip to brighton university Leaf hospital to participate in what would be my first cadaver prosection experience. Until this point I had never seen a dead body at all, let alone in person, so it would suffice to say I was intrigued at what it would be like. When we arrived we were taken to a room just to be told by the medical students what to expect and Then were taken into the prosection room where we put on some lab coats and gloves.
There were two bodies which had been donated to this procedure, both were women at an old age. One was a set of two legs which had been separated and the other a full body. We first observed the two legs and saw all the layers of tissue and muscles as well as ligaments. The other body was very intersting as well as it revealed the circulatory, respiratory, and digestive systems in the body. It was fascinating how these key systems all interact with each other to allow life to function. I had no concept before of the intricate complexity of even the most simple of systems in our body. What I have taken away from the experience was a new found respect for the intricacy and fragile nature of the human body and a want to further develop my understanding of the specific body parts The afternoon tea we had with those from the living well with dementia group was a fascinating insight into the effects of the disease in day-to-day life. What I found particularly interesting was the discussion about the deep psychological stimulus that helped those suffering from the disease, to remember something from their past. One such example was given for one lady named Irene who said that listening to specific songs from the classical genre of music helped her to remember small events and places from her past. This to me indicates that despite the disease’s long-term effects on our memory, some events are still embedded in our deeper psyche, which only need a small prompt, either a sound, smell, image, or texture to allow us to access them. Which raises a rather interesting question, can we ever truly loose a memory... or is it just a case of unlocking it from deep within our brains?
I found this trip to be a truly enriching experience. When we went to the Hunterian museum we attended a two part lecture, in between each part we went in groups comprised of students from all over the country and with different backgrounds to discuss a certain topic within the Use of Human Tissue subject. It was a very free environment which allowed us to explore our thoughts much further than was originally intended, We spoke mainly about consent and what sort of system we should have in place and how we should go about our research on human tissue. My favourite part was at the end where we discussed the issue of consent around someone who had a multiple personality disorder and a situation where one personality consents to organ donation and the other doesn’t. Assuming said person is over 18 and has had no objection from family, the decision to opt into the process out weighs the situation not to, at least in this country.
I think this has furthered my interest into neuroscience and neurosurgery and my wish to learn more about the human psyche. Also it has furthered my interest into multiple personality disorder and those who suffer from it. I will be reading more journals on this and news articles. http://www.bbc.co.uk/news/health-37848305
Above is the link to the BBC article related to this I personally do think that we could be facing a very serious problem with our excessive use of proscribed antibiotics. It's essentially accelerating the process of natural selection in the dangerous bacteria. All the bacteria will begin to be killed off by a new drug until one mutates a gene which has a resistance to the drug. While others die off, this bacterium will continue to multiply, and spreading until the only types of that bacteria left are the ones with the gene immunising them against the antibiotics. Meanwhile we are not thinking of the bigger picture. This will help us out in the short term but in the long run we are only damaging ourselves more. Eventually we will find that only those resistant to antibiotics remain. So thats why in my opinion I would say we should stop investing the little time we have left in antibiotics made of other bacteria and fungi but to look to other solutions instead such as peptides. Here is a few paragraphs form the online journal Nature that explain the reasoning behind using peptides. "Plants, animals and fungi have vastly different immune systems, but all make peptides — small proteins — that destroy bacteria. Peptides from creatures such as amphibians and reptiles, which are unusually resistant to infection, could yield new therapeutics. Peptides with antibacterial activity have been isolated from frogs, alligators and cobras, among others, and some seem to be effective in epithelial cell cultures and at healing wounds in mice. These peptides can be modified to increase their potency, and several are in clinical trials. One, called pexiganan, based on a peptide from frog skin, is now in phase III clinical trials to treat diabetic foot ulcers. But synthesizing such molecules can be expensive, a hurdle that scientists must overcome to bring new peptide drugs to market." I understand the expense of this trial but I think we would all agree it is money well spent in order to prevent a potential "super" plague made up of antibiotic immune bacteria. I also think the system put in place to help remind the doctors to reduce proscription will very much help and should be implemented in every clinic across the globe to help prevent one of the greatest possible pandemics we could face as a species. An Investigation into the change in rate of reaction of the catalase enzyme based on changes in pH11/7/2016 ObjectiveDuring this experiment we wanted to see the affect of different pH levels on the rate of reaction on the enzyme catalase. Catalase is an enzyme found commonly in every cell in our bodies and is vital to our survival. It converts the toxic bi-product of respiration, Hydrogen peroxide, to water and oxygen. HypothesisI predict that the enzyme will function the most efficiently in the alkaline environment. Most likely at a 9-10 pH as it has to function inside the cell cytoplasm ApparatusSafety Goggles Timer Spotting Tile Petri dish of filter paper discs forceps 10ml syringe (for distilled water) 2ml syringe (for Hydrogen Peroxide) 1ml Pipette (vol of bean juice! & Buffer solution) 10 mung beans (catalase!) Hydrogen peroxide (1% concentration) Distilled water pH buffers Washable marker pen Peroxide containers Method
ResultsWhat does this evidence show? Clearly we can see a huge decrease in the length of time required to send the paper to the top, when the pH increases (note the pH increases from right to left going 5,7,8,9,10). What this shows is that the best conditions for this enzyme to work in is an alkaline condition. We can also safely assume that the optimum pH is 10 as this is the one with the lowest average time to produce enough oxygen to float the disc. However there is no significant impact on the results from the alkaline as the error bars overlap. However with our acidic result we see no overlap. So this suggests there may be a significant difference in the results. This is supported by the fact that the enzyme would have been denatured, and so would have had a significant impact on the rate of reaction. So I can conclude my hypothesis correct. How to Improve the ExperimentThe main aspect about the experiment that could of been improved, is the number of tests on the lower pH. We should have included more acidic pH's, in order to confirm the exact pH where the enzyme denatures. We could of also had more repeats to increase reliability as the results are quite close.
ObjectiveTo be able to observe the cross section of the Rat Kidney cells under a light microscope and identify where the loops of henle are. Method. First set up the microscope carefully, being sure never to touch the objective lenses . Then place the slide containing the sample onto the stage, clipping it into place . Adjust the dials to bring the slide as close as possible to the objective lens without making contact. . Put your eye up to the eye piece and slowly adjust the dial, brining the stage lower, until you can clearly see the sample . After doing this attempt to locate the part of the image that is the loops of henle ObservationsThe slightly smaller circles in the image were positively confirmed to be the loops of henle. The numerous quantity of them reflects the human need for osmoregulation during homeostasis.
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