What factors affect osmosis?
What factors affect osmosis? In my investigation I am going to attempt to discover if osmosis is affected by a certain factor. Osmosis is the movement of water from an area of high water concentration through a semi-permeable membrane to an area of low water concentration. Osmosis is affected by water potential which is the term used to describe the movement of a concentration of water, and as a general rule water always falls from an area of high water concentration to an area of low water concentration in a similar way to gravitation or electrical potential. In simple terms, it is sometimes referred to as the diffusion of water. I am going to find out how the concentration of a solution affects osmosis in an investigation using potatoes and sucrose solution. Osmosis depends upon a semi-permeable membrane because this allows water to pass both ways through the membrane but not other solutions with larger molecules, for example sucrose solution (see diagram to the right). A number of factors could affect osmosis such as; type of plant material, temperature, type of solution or concentration of solution. I could have chosen to investigate any of these factors effect on osmosis but instead I chose to investigate the concentration of solution, as I believe it will have the greatest effect on osmosis and will allow me to show a higher level of scientific knowledge and I chose
The effect of antibiotics on the growth of bacteria.
The effect of antibiotics on the growth of bacteria. The Aim: The aim of this investigation is to find out what effect out of two antibiotics, penicillin and streptomycin has on the growth and multiplication of two different species of bacteria. The two different types of bacteria we will be using are E-coli and micrococcus luteus. The Apparatus: * Four sterilised Agar plates, * Glass spreader, * Masking tape, * Wax pencil, * Lab roll, * A beaker with 70% alcohol, * E- coli (Culture) * Micrococcus luteus (culture), * Penicillin (antibiotics), * Streptomycin (antibiotics). Scientific Knowledge: E-coli: E-coli are a common type of bacteria and are short for the medical term Escherichia coli. This normally lives inside your intestines, where it helps your body break down and digest the food you eat. E. coli bacteria was discovered by a German bacteriologist Theodor Escherich in the 1885.The organism can be found on a small number of cattle farms and can live in the intestines of healthy cattle. But also we need it in our bodies to keep them healthy we pretty much depend on E-Coli in our intestines to provide us with Vitamin K and B complex vitamins which play a vital role in keeping us strong and healthy. Penicillin: Penicillin was the first naturally-occurring antibiotic discovered and was the first one to be used therapeutically Penicillin was discovered by
Investigating the effects of surface area on the rate of enzyme reactions.
AS Biology Coursework assignment Investigating the effects of surface area on the rate of enzyme reactions By Scott Humm Introduction Enzymes basically are biological catalysts. What this means is they have the ability to speed up reactions without actually being used up themselves. Enzymes are globular proteins and they have a three-dimensional shape, which is very precise and never varies between two examples of the same protein. The active site for all molecules of the same enzyme will be made up of the same arrangement of amino acids. This exact shape and arrangement of amino acids enables the enzymes to be highly specific and this defines which substrate they bind to in the active site. Because they are so specific, enzymes are thought to catalyse substrate into two different products by the "Lock and Key hypothesis". Diagram taken from http://schools.moe.edu.sg/chijsjc/Biology/Enzyme/enzyme.htm This diagram shows how enzymes catalyse the breakdown of a substrate molecule into two products. The only way that another molecule can bind with an enzyme's active site is if it is an inhibitor. Inhibitors are molecules that can bind with the active site briefly causing competition between itself and any substrate molecules. When there is a very high concentration of inhibitors, substrate molecules do not bind with active sites as easily because there are less of them.
The Process of Human Digestion
The Process of Human Digestion Digestive System, series of organs put together that purpose is to break down, or digest, the food we eat. Food is made up of large things called, complex molecules, which the digestive system breaks down into smaller things called simple molecules that get absorbed into the bloodstream. The bloodstream is our blood. The simple molecules travel through the bloodstream to all of the parts of the body, which we use for growth, repair, and energy. All living things that eat to get energy have a digestive system, a feature that makes us different from plants. Plants make their own food in a process called photosynthesis, photosynthesis is when plants make sunlight to convert water and carbon dioxide into simple sugars. But animals, including humans, must take in food in the form of organic matter, such as plants or other animals. Digestion generally involves two parts: a mechanical part and a chemical part. In the mechanical part, teeth physically break down large pieces of food into smaller pieces. In the chemical part, digestive chemicals called enzymes break apart individual molecules of food to yield molecules that can be absorbed and distributed throughout the body. These enzymes are secreted by glands in the body. The digestive system of most animals consists mainly of a long, tube called the alimentary canal, or digestive tract. This canal
Does listening to music affect your heart rate?
Does listening to music affect your heart rate? Introduction: The pulse is an indirect sign of blood pressure and heart beating, which is controlled by autonomic nervous system. Cardiovascular and endocrine responses to musical perception which have been studied largely show different changes depending on the situation of the subject (musical experience, handedness, gender, age) and the type of musical stimulus (sedative, harmony music or rhythmic rock music detailing in simple musical elements like intervals, chords, pitch, timbre; or complex musical structures). In a trial, the heart rate was found to decrease after listening to classical and New Age music but not to change after listening to popular music. The heart rate was found to increase if the music contains a fast beat or slow down if the music encourages physical and mental relaxation. Although changes of heart rate and blood pressure as related to listening to music have been reported by many investigators, the complicated problem is still obscure and need deep investigation to clarify its mechanism. Aim: To study and find out if music actually affects our heart rate and if so how? I will also attempt to see if the heart rate changes whilst listening to different types of music at different volumes. Prediction: I predict that listening to music should actually increase/speed up the heart rate as more
Myocardial infarction
Case Study 2006 Myocardial Infarction Sharon Thomas Waitakere Hospital Abstract Of This Case Study Have you ever wanted to know what a Myocardial Infarction is and what its all about. Read on and find out through my eyes, about a patient I was caring for - what happened to him in both his body and mind. The following will show what a Myocardial Infarction ( MI ) is, what happens in the patients body and what care is involved by the medical and nursing teams. All of this to ensure my patient would walk out of hospital and again feel like productive member of society that he most certainly was before his cardiac event. Also within the body of this case study will be evidence based articles to support statements made. Congruent to this, will be reflection on how all that transpired with this man affected me and how my nursing practice has developed because of it. This patients health related journey and the anonymous intimacy that took place, came to a happy conclusion for both nurse and patient. Judith Christiansen's Nursing Partnership Model was published in 1990 and was developed in response to the knowledge gaps in the nursing system in New Zealand ( Taylor, 1995 ). This partnership model is a theoretical framework for nursing practice. It has 3 major concepts - these being nursing partnership, the passage and the context. Anonymous Intimacy is one of 3
Use of a redox indicator to show dehydrogenase activity.
Use of a redox indicator to show dehydrogenase activity Introduction: Triphenyl tetrazolium chloride (TTC) is an example of an artificial hydrogen acceptor, or redox indicator. TTC is colourless when oxidised, but forms red, insoluble compounds called formazans when reduced. TTC can therefore be used to show the presence of active dehydrogenase enzymes by a colour change. This experiment investigates the effect of temperature on the activity of dehydrogenases in yeast cells. Materials: * Actively respiring yeast suspension. This should be prepared by adding 100g of dried yeast to 1dm3 of water and mixing in 50g glucose. This mixture should be allowed to stand in a large beaker for about 2 hours before the experiment. * Triphenyl tetrazolium chloride solution, 0.5% * Distilled water * Test tubes and rack * Graduated pipettes, or syringes * Glass rods * Crushed ice * Beakers or water baths * Thermometer * Stopwatch Method: . Set up water bath at 30?C. 2. Pipette 10cm3 of yeast suspension into one test tube and 1cm3 of TTC solution into another test tube and stand them both in the water bath. Leave for several minutes to reach the temperature of the water bath. 3. Mix the yeast suspension and TTC solution together and return the test tube to the water bath. Start the stopwatch immediately. 4. Observe carefully and note the time taken for any colour
Explain how arteries, veins, and capillaries are adapted for their functions. Describe what happens in coronary heart disease and explain how lifestyle may contribute to the development of this disease.
Explain how arteries, veins, and capillaries are adapted for their functions. Describe what happens in coronary heart disease and explain how lifestyle may contribute to the development of this disease. The human circulatory system is an essential network of tubes designed to transport a continuous flow of blood throughout the body delivering nutrients to and removing waste from every cell. Contemporary society is experiencing an increasing number of people suffering from an often preventable disease that occurs in this circulatory network named coronary heart disease. (Boyle, M., Senior, K. 2002). (www.nhlbi.nih.gov/health/public/heart/other/chdfacts.htm). This essay will explain how the circulatory systems' arteries, capillaries and veins are adapted for their functions, what happens in coronary heart disease, and how some contemporary lifestyles may contribute to the condition. The main organ of the circulatory system is the heart, situated in the chest between the lungs. It is a hollow muscular structure consisting of four main chambers. The lower left and right ventricles have thick muscular walls to pump blood, and the upper left and right atria that have thinner walls and receive blood. This is effectively a double circulatory system as both ventricles pump blood and both atria receive blood simultaneously. The pulmonary system starts in the right
The Effect of Temperature on Amylase
The Effect of Temperature on Amylase Planning Independent Variable: -Temperature of the solution (°c) Dependent Variable: -The time taken for the amylase to digest the starch (mins) / The rate of the enzymatic reaction (1/min) Aim: The aim of this experiment is to investigate how temperature affects how well amylase works. Prediction & Hypothesis: Amylase is an enzyme which breaks down starch to glucose. Enzymes are globular protein molecule that accelerates a specific chemical reaction. Enzymes lowers the activation energy (-the minimum amount of collision energy required to get the reaction going) and when the temperature increases, the enzymes work faster. ?As the temperature increase, the rate of the enzymatic reation will also increase- The time for the amylase to digest the starch will also be faster as the temperature increase. This is because the higher the temperature, there are more collisions required for the activation energy to get the reaction going. Rising the temperature makes the substrate (in this case, the starch molecules) collide more often with the active site (in this case, the amylase) which results in faster rate of enzymatic reaction. ?The best temperature range for the amylase to work best at is 35-40°c- This is because if the temperature is too low (0-5°c), there will be less collision between the substrate and the active site
Agar Jelly Experiment Report
Aim: To find out the speed of diffusion in agar jelly, when there are three blocks of jelly of different sizes. Material: A container with agar jelly, safety goggle, knife, ruler, stop watch, a glass plate, sodium hydroxide, an indicator. Method: First, we took the block of agar jelly from the container. We placed it onto the glass plate, and took our knife and ruler. We measured and cut the block, making three cubes of different measurements. The smallest one is 1cm by 1cm by 1cm, the second one is 2cm by 2cm by 2cm, and the biggest one is 3cm by 3cm by 3cm. We then dropped a few drops of the indicator. Next, we put our safety goggles on, and took the beaker full of sodium hydroxide, and poured it into the glass plate, which the cubes are in. At the same time, we started the stop watch. We saw everything, the cubes, sodium hydroxide turn pink (that's because sodium hydroxide reacted with the indicator). When the stop watch showed 5 minutes, we took the cubes, and cut all of them in half. Then we measured the distance from the surface, to the line where the pink and the white color separate, like on the diagram, using our ruler. We recorded what we saw, and the results. Results: We saw the cubes turn pink, and the sodium hydroxide turn pink on the plate. We also saw, when we cut the cubes that the pink color travelled into the cube, and we saw that at a certain
