An investigation into the antibiotic effects of penicillin and streptomycin on the bacterium Escherichia coli
Risk Assessment: Risks related to substances, apparatus or procedures Precautions to be taken Contamination of microbes: To prevent this, it will be important to follow sterile techniques throughout. I will be wearing gloves at all times during the handling of the microbes. I will also take utmost care when handling the cultures that I do not drop them, as this could easily cause them to spread if the container being used, were to break open. For example, the microbes could spread aerobically. It would also be a good idea to work near a Bunsen burner at all times so that an updraft of air is created, causing constant airflow and therefore less chance of unwanted pathogens from settling in the microbial cultures. An investigation into the antibiotic effects of penicillin and streptomycin on the bacterium Escherichia coli. Aim: To plan an investigation into the antibiotic effects of penicillin and streptomycin on the behaviour of the bacterium E. coli. Introduction: I will be carrying out this experiment to find out which antibiotic (penicillin G or Streptomycin) is more effective at killing the bacterium E. coli. This information could be useful to a number of people, but an investigation of this nature would prove most useful to members within the medical profession. This is due to the fact that it would enable them to treat patients with more knowledge and
Ocr Biology B3-Animal Extinction
The red squirrel or Eurasian red squirrel (Sciurus vulgaris) is a species of tree squirrel (genus Sciurus). A tree-dwelling omnivorous rodent, the red squirrel is common throughout Eurasia. In Great Britain, numbers have decreased drastically in recent years, in part due to the introduction of the Eastern Gray Squirrel (Sciurus carolinensis) from North America The red squirrel may have only ten years unless a vaccine is found to protect it from squirrel pox. Red squirrels have reddish-brown fur with a white chest and, in winter, they have characteristic long, red tufts of fur on top of their ears. Red squirrels spend almost all their time in the treetops and rarely come down to the ground. High up in the branches, they build nests called dreys out of twigs nibbled off trees which they line with moss, dried leaves or grass. At the moment the MP calls for support on the red squirrel. David Maclean, former Tory chief whip and MP for Penrith and the Border, said a select committee inquiry was needed because Government policy was in disarray, with Government departments and agencies north and south of the Scottish border pursuing different strategies, none of which were working. Grey squirrels, which carry the squirrel pox virus that is fatal to reds, recently caused the death of red squirrels at one of their last redoubts on the sands at Sefton in Lancashire, while in
Osmosis. An experiment to find the concentrations of salt solution which is the same as the concentration of cell sap in a potato.
An experiment to find the concentrations of salt solution which is the same as the concentration of cell sap in a potato. Concentration of salt in solution/ % Mass of potato core at start/ g Mass of potato core at end/ g Change in mass/ % % change in mass/ % 0 2.03 .99 - 0.04 - 1.97 8 2.13 2.05 - 0.08 - 3.75 6 2.14 2.12 - 0.02 - 0.93 4 .95 .93 - 0.02 - 1.02 2 2.16 2.11 - 0.05 - 2.31 0 2.17 2.15 - 0.02 - 0.92 Investigation > To find out about osmosis in potato cells. > To find the concentration of salt solution which is the same as the concentration of cell sap in the potato. Prediction > The higher the concentrations of salt solution, will make the potato go flaccid. > However, the lower concentrations of salt solution will make the potato go turgid, increasing the length and mass. Biological knowledge which supports prediction > Osmosis- diffusion of water molecules from a dilute solution to a concentrated solution across a semi-permeable membrane. > Potatoes don't have a very salty taste so there is a probably a more dilute solution of salt solution in the cell sap. > When there is a high concentration of salt solution, the water will diffuse from the potato across the semi-permeable membrane, into the salt solution. Independent variable: (thing that changes) > Concentration of salt solution Dependent variable: (what you are
Discuss the importance of plants on planet earth
Discuss the importance of plants on planet earth Plants As We See Them Plants are all around us, renowned for their aesthetic appeal; their colours and structures lend themselves to decoration. Plants are used in celebrations and commiseration's and are often celebrated in their own right- the annual Michigan potato festival being a good example. Plants are associated with national identity. The Scottish thistle; Irish Shamrock; Welsh leeks and daffodils. Many national flags feature plants, the Cedar tree on the Lebanese flag, and the Maple leaf on the Canadian flag. However all of these commendations can not begin to celebrate the real importance of plants on planet earth. In this essay I will explore the biological and physical importance of plants and the issues surrounding them. The Real Importance For millions of years the chemical needs of the biosphere have run on solar energy. Plants (along with some bacteria and green algae) are autotrophs that have the ability to convert this solar energy into chemical energy by a process called photosynthesis. This chemical energy, stored in plants is the fuel that sustains life. PHOTOSYNTHESIS: The Light Reaction. Photosynthesis takes place in the leaves of plants. There are two stages; the light-dependant or light reaction and the light-independent or dark reaction. In photosynthesis the light reaction, for which the
HEART DISEASE The heart pumps blood around the body, supplying oxygen to all the organs, including the heart itself.
HEART DISEASE The heart pumps blood around the body, supplying oxygen to all the organs, including the heart itself. The vessels that carry blood to the heart muscle are called coronary arteries (1). There are two sides to the heart, each of which acts as a separate pump. The two halves are sub-divided into four chambers, so there are four chambers in all (2). A healthy heart will function in this way, but disruptions along the cardiac cycle can cause serious problems to the heart and lead to conditions, such as Heart disease. Coronary heart disease or (CHD) is more common in the elderly and affects 4 times more men than women according to recent studies (2). Coronary heart disease comes in two main forms: heart attack and angina. The coronary arteries become narrow with the build-up of fatty deposits, which may build-up over the course of 20-30 years. This will reduce the flow of blood to the heart and increases the chances of a blood clot blocking the artery, and becoming lodged in the coronary vessel. The blood cannot reach the heart muscle beyond this clot and a section of the heart then dies. This is also known as thrombosis (4). Thrombosis is one of the central problems in coronary heart disease. It is the cause of sudden deterioration in angina and most heart attacks. Fatty deposits known as 'plaques' are made up of many substances including a fatty substance
As I watch, the waves from the shore look fun and almost innocent as they crest and crash over one another
My Ocean Adventure Matthew Eden As I watch the waves from the shore look pleasing and almost harmless as they crest and crash over one another; I can taste the salt in the air and watch little rainbows glisten through the prisms of the ocean's spray. The warm ocean water towards the shore is covered with foam and bubbles from the rumbling waves as children and their families play in the gritty, tan sand. "This is perfect," I utter to myself. I make the final preparations on my Yamaha Waverunner. All of the fluid levels are full and there is a faint smell of gasoline mixed with the aromas of salt and fish in the air. I am now ready to step up and take on the mighty waves of the South Padre Island! Before the truck backs the trailer into the warm waters at the dock and lowers the Waverunner into the blue-green abyss; I crank the engine for a final systems check. It roars powerfully like a lion, drowning out the sound of the birds circling overhead, as thick black and grey smoke initially pours from the exhaust and then slowly drifts away on the wind's light breezy blow. I turn the grand machine off to finish my final preparations. As I put on my Jet Pilot lifejacket and tighten the thick blue straps, I remind myself to stay calm and not to make any stupid or impulsive decisions during my journey into the ocean. It is easy to push oneself to the limits and lose
How the structure of the heart allows it to function
How the structure of the heart allows it to function Every cell in the body requires a supply of oxygen and food, luckily, that's exactly what the blood does, providing a transport medium to deliver critical supplies and also to remove harmful waste products to the cells. However, without a pump, blood is next to useless if it cannot get to the cells in the first place. The role of the heart is to pump blood around the body. It has to do this about 70 times a minute, 60 minutes an hour, 25 hours per day, from the day your were born to the day you die. Therefore, the heart has to be efficient at pumping about 4300 gallons of blood each day, and respond according to the body's metabolic rate. For example, when you exercise, your heart rate increases to meet the demand for more oxygen that is required in respiration (release of energy from food) and also, to quickly get rid of the by-products - carbon dioxide. The heart is an organ, about the size of a clenched fist (pretty small for a critical role that it plays in the body), situated between the lungs and protected by the sternum (breastbone), the heart comprises of specialised cardiac muscle tissue. The actual structure of the heart consists of 4 chambers, 2 chambers on each side, separated by the septum. The septum ensures that neither oxygenated blood and deoxygenated blood mix together. This ensures that blood with
The aim of this experiment is to find out which side of a tree the most Pleurococcus grows upon, and why this is so.
Aim The aim of this experiment is to find out which side of a tree the most Pleurococcus grows upon, and why this is so. Prediction I think the most Pleurococcus will grow on the North side of the tree. I think this will happen because, the south side of the tree receives the most sunlight. The heat from this sunlight would dry out the Pleurococcus, which would cause it to dry out, and die. As Pleurococcus is an algae, it photosynthesises. This means it needs water as is shown in the photosynthesis equation below. Water + Carbon Dioxide Oxygen + Glucose (aq) (g) (g) (s) 6H20 + 6CO2 6O2 + C6H12O6 (aq) (g) (g) (s) If it can not photosynthesise, it will not have enough energy to grow, reproduce, respire, and repair, it will, therefore, die. The other input into photosynthesis, is Carbon Dioxide, because Carbon Dioxide is a gas, and diffuses, it will not affect our experiment. The other thing that Pleurococcus needs to photosynthesise, is sunlight. Even in the North, there is enough sunlight for it to photosynthesise. The sunlight in the North is not enough to dry it out, because Pleurococcus has heavy cell walls, which prevents excessive water loss. Fair test To ensure this is a fair test, I will be measuring 10 different trees, instead of just one. This is because, if just one tree was measured, the results from that
Study the condensation of steam at different temperature levels
David Holden 13T Physics Investigation For my physics coursework, I have to decided to study the condensation of steam at different temperature levels, I will then set about studying how to prevent condensation of steam on a general household object that is frequently subjected to steam on a daily basis - a sheet of glass (eg. A mirror in a bathroom) It became apparent to me that studying this topic would not be easy when I put some thought into it, my initial idea was having a mirror, that would heat itself as more water vapour entered the atmosphere, preventing water vapour condensing on it. (A simple example of this is when spectacles are 'steamed up', run them under hot water for a few seconds to wash away the condensed water, and more importantly adjust the temperature of the spectacles to the surroundings to prevent further condensation of water.) For a practical everyday mirror for this purpose, it would be easy to run a heating element along the backside of the mirror (to conduct the heat through to the mirror surface) and link the heating element to a variable resistor, which in turn would be connected to the hot tap handle, so in theory, the more hot water flowing through the bath tap/showerhead, the more water vapour produced so in turn the hotter the mirror becomes. This idea is easy enough, but the problems start with calibrating the variable resistor, ie, how
Osmosis Coursework
Osmosis Coursework Planning Before I started this coursework I learnt about osmosis. Osmosis is the diffusion of water molecules from a region of high concentration to a region of low concentration through a semi-permeable membrane. In a high concentration there is a lot of solvent (water) and less solute (salt). This is called a dilute or weak solution. In a low concentration there is less solvent (water) and more solute (salt). This is called a strong or concentrated solution. First of all I will cut the potato with the knife. Then I will use the scalpel to cut the potato into twenty equal strips and I will use a ruler to cut them into the same length. Then I will put two strips of potato into each of the ten petri dishes. I will then take salt solutions and pour different concentrations from 0.5%-5% into the petri dishes. I will then leave them in the dishes for the same amount of time and then take them out and measure their lengths. I will then record the results in a table and then draw a graph of the results. Equipment Salt solution of different concentrations 0 petri dishes used to put salt solution and potato in Potato cut up into pieces to be put in salt solution Scalpel used to cut up potato into equal strips Ruler used to measure length of potato before and after experiment Cutting tile used to cut potato on
