Experiment to investigate the effect of different antibiotics on the bacteria Bacillus subtilis:

Experiment to investigate the effect of different antibiotics on the bacteria Bacillus subtilis: Aim: To see which antibiotic (Chloramphenicol, Erythromycin, Fusidic Acid, Oxacillin, Novobiocin, Penicillin, Streptomyan and Tetracycline) reacting with the Bacillus subtilis has the largest zone of inhibition in mm (+/- 0.5mm) and so which has the biggest effect on the bacteria. Introduction: Gram -positive bacteria are bacteria that are dark blue or violet when gram staining. Gram-positive organisms are able to keep the crystal violet stain because of a high amount of peptidoglycan in the cell wall. This makes up about 90% of the thick, more than 20 layers of peptidoglycan together. Gram-positive organisms normally do not have the outer membrane, whereas Gram-negative organisms do. Gram-positive bacteria include many well -known genera like Streptococcus and Bacillus. Most pathogenic bacteria in humans are Gram-positive organisms and these are used to manufacture antibiotics. Bacillus subtilis, also known as the hay bacillus or grass bacillus is a Gram- positive bacterium, which is mostly found in soil. Bacillus subtilis is not a human pathogen and it can contaminate food but rarely causes food poisoning. Bacillus subtilis spores can survive the extreme heat during cooking and Bacillus subtilis is responsible for causing a sticky, stringy consistency in spoiled bread

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Biology: Lab report Germination

Biology Lab Report Seed Germination By: John Abarshi (Figure One: Cress Seed Germination) Introduction This term, we embarked upon our first biology experiment. Recently, in class, we have been learning about plant reproduction. Amongst the vast amount of information pertaining to the topic of plant reproduction is germination. Germination is the process of sprouting, whereby seeds or spores sprout or emerge and begin to grow. [1] [2] When a seed is germinating, certain factors affect its germination. It was our task to come up with two variables that could influence seed germination and to investigate this. After much contemplation and consideration, I managed to pinprick what factors I would like to investigate. I will thus investigate if altering the light and temperature of the cress seeds' environment will affect the germination. Research Question How do light and temperature affect the germination of a cress seed? Hypothesis If cress seeds are placed in a dark environment, then their germination will be negatively affected compared to cress seeds grown in a normal light environment because seeds If cress seeds are placed in an environment with excessive exposure to light, then their germination will be positively affected compared to cress seeds grown in a normal light environment because seeds If cress seeds are placed in a cold environment, then their

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The effect of Pectinase Concentraton on the production of apple juice

The effect of Pectinase concentration on the production of apple juice The aim of this experiment is to see the effect different Pectinase concentrations have on the production on apple juice. Pectinase is an enzyme which breaks down pectin, a polysaccharide found in plant cell walls. This enzyme is mainly commercially used to speed up the process of fruit juice production as the cell walls of plants are broken down more quickly. Therefore by changing the Pectinase concentrations, the results may show the effects it may have on how much apple juice will be produced. Hypothesis: As the concentration of the Pectinase increases in concentration, there will be more apple juice produced. However, after a certain amount of Pectinase concentrate, the volume and intensity of apple juice produced would not increase anymore because there is a limit of active sites in the Pectinase for the pectin in the cell walls of the apple to react with and therefore the apple juice produced will not increase further. Null Hypothesis: As the concentration of the Pectinase increases there will be no change in the volume or intensity of apple juice produced. Variables: Independent - The concentration of Pectinase (1, 2, 3, 4, 5%) The different concentrations of enzyme will be used to determine whether or not they have an effect on the production of apple juice. By using a range of

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The Roles of ATP

The Roles of ATP ATP, or Adenosine triphosphate, is an organic chemical compound that has a strong chemical bond which acts as an energy fuel, it isn't a long term energy store as the bond is quite unstable so when ATP is made it is used almost immediately, when this bond is broken it releases chemical energy which can be used straight away for many functions, it is considered in biology to be the currency of life. This energy gets released when a phosphate is broken off, you can get a small energy release from one phosphate leaving the ATP; when one leaves you get ADP. The ADP can then be recharged back to being ATP in the mitochondria of our cells, using respiration; this is how we get energy from food. ATP can also give up bigger amounts of energy if it is needed, when it gives up two phosphates, leaving AMP. ATP has many roles because it is the primary source of energy in living things , we use it in our body to contract muscles for movement, for active transport, it even lights up fireflies, it powers almost every activity that goes on in our cells. As far as it is known every living thing uses ATP as its primary source of energy, from bacteria to plants. At any instant in time a cell in the human body can contain about one billion ATP molecules, but this amount is used up quite quickly and is normally recycled straight away in the mitochondria where chemiosmotic

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The effect of temperature on amylase activity

Kiu Yi, IP 13M The effect of temperature on amylase activity Introduction The purpose of this experiment is to investigate if temperature will affect the amount of starch broken down as enzyme activity can change by different temperature. This is because as temperature rises the rate of chemical reactions increases due to the temperature increases the rate of the molecules' motion. More interactions will be existed between an enzyme and its substrate. The enzyme used in this lab exercise is amylase, which is commonly found in saliva and germinating seeds, catalyzes the breakdown of starch. It also reacts quickly when heat is present during the process of it reaction. However, if the temperature is higher than the optimum point, enzymes can be denatured and they can no longer bind to a substrate and catalyze reactions. My hypothesis is therefore the amylase activity would increase as the temperature rise, until a certain high temperature at which the amylase would denature and be non-functional. In this experiment, I will observe the activity of amylase by using iodine as iodine reacts with starch to form a dark brown/purple color. After adding in iodine, when amylase breaking down starch, less and less starch will be present and the color of this solution will become lighter and lighter. Equipments • 0.1% Amylase 0.5 ml • 1% Starch 5ml • 10 Test tubes and

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Effect of substrate concentration on catalase activity (Biology IA)

Title Effect of substrate concentration on catalase activity Aim To prove that at different concentrations of hydrogen peroxide, the rate of catalase activity in chicken liver differs. Hypothesis When chicken liver is exposed to hydrogen peroxide, the higher the concentration of the solution, the faster the activity of catalase because the decomposition rate of hydrogen peroxide increases when its concentration is higher (in the presence of chicken liver). Variables Independent Variables * Concentration of hydrogen peroxide Dependent Variables * Time taken for coloured liquid to rise by 5cm against different concentrations of hydrogen peroxide Controlled Variables * Amount of chicken liver used - cubes cut with a scalpel to approximately 1cm x 1cm x 1cm * Amount of hydrogen peroxide used - 5cm3 measured with a syringe before addition to the chicken liver * Temperature of liver (not controlled) * Age of liver (not controlled) * Source of liver (not controlled) Materials and Apparatus Materials: Apparatus: * 6x Chicken Liver Pieces - 1cm x 1cm x 1cm * 5% Hydrogen Peroxide Solution (5cm3) * 4% Hydrogen Peroxide Solution (5cm3) * 3% Hydrogen Peroxide Solution (5cm3) * 2% Hydrogen Peroxide Solution (5cm3) * 1% Hydrogen Peroxide Solution (5cm3) * 0.5% Hydrogen Peroxide Solution (5cm3) * Coloured Liquid * Distilled Water * 3x 20cm3 Syringes * 1x

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IB BIOLOGY INTERNAL POTATO OSMOSIS

Aim: To investigate the effect of changing solute concentrations on the process of osmosis in potato chip of a given size. Hypothesis: I predict that as the solute concentration increases, the mass of the potato will decrease because due to osmosis, water has the tendency of flowing to an area of low concentration from an area of high concentration, and as the solute concentrations increase, there will be a lower concentration of water in the solution, hence the potato mass will decrease. The independent variable in this experiment will be the solute concentrations. Water and sugar solutes of 0.1, 0.3, 0.6 and 0.8 mols -1 will be used in the experiment The dependent variable in this experiment will be the mass of the potato chips after osmosis compared to before the osmosis. There are several controlled variable worth mentioning. Make sure all potato chips used are of the same length, by measuring each with a ruler. Use only solid, whole potato chips, check the solidity by observing each chip. Measure the quantity of solutes used with a measuring cylinder, and measure at eye level to obtain accurate measurements, use the same amount of solute for all types of concentrations. Control the time period allowed for osmosis, by timing with an electronic timer from the exact moment the chips are placed in the solutes. The cups used for the solutes must be completely dry before

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Enzyme Coursework. Investigation to find the effect of substrate concentration on the rate of an enzyme controlled reaction

Investigation to find the effect of substrate concentration on the rate of an enzyme controlled reaction Design Aspect 1: Defining the problem and selecting variables Investigation title: is the rate of an enzyme controlled reaction affected by substrate concentration? Background information Enzymes are often referred to as "biological catalysts", since they increase the rate of reactions in living organisms. Enzymes are also substrate specific, which means that only a specific substrate can fit into its active site (which is where the catalysing effect occurs) and as such, there are different enzymes which deal with different reactions (for example, protease breaks down proteins into amino acids) - this is the basis for the 'lock and key' theory. The stages of an enzyme controlled reaction are: ) Enzyme + substrate The enzyme and substrate are in solution together 2) Enzyme substrate complex A substrate has moved into the active site 3) Enzyme product complex The reaction has taken place, but the products haven't been released from the active site 4) Enzyme + product The enzyme and product are now in solution together (after the product was released from the active site) The rate of an enzyme controlled reaction are mainly affected by: temperature, substrate concentration, enzyme concentration and pH. By increasing the substrate concentration, there is a higher

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The Effect of Temperature on Enzymatic Activity. Aim To investigate enzyme activity of yeast on glucose at different temperatures

Effect of Temperature on enzyme activity Aim To investigate enzyme activity of yeast on glucose at different temperatures Hypothesis As the temperature increases, enzyme activity will also increase. At lower temperatures enzyme activity will be less than when the temperature is higher. Also if temperature is increased too much, enzymatic activity will fall. This is because the molecules in glucose will move faster and the enzymes will be have increased activity because of increased movement. Also since all enzymes have an optimum temperature at which enzymatic activity is the highest, increasing the temperature will move enzyme closer to optimum temperature. But if temperature is increased too much, enzyme will start to denature (loss of three-dimensional structure) and thus the enzymatic activity will fall again Key Variables Independent: Temperature Dependent: Enzymatic activity (number of bubbles) Controlled: Amount of water that the solution is submerged in Time Concentration of glucose Materials • • 100mL beakers x5 (label from A-E) • • 5 cm3 syringes x5 • • 10 cm3 of 10% yeast solution • • 15cm3 of 2% glucose solution • • 1 thermometer • • 2 hotplates • • Stopwatch • • Ice cubes x 6 • • 400mL water • • Observations chart & pen Method . 1. Place 6 ice cubes and 80 mL of water into Beaker A 2. 2. Measure

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Neurology and Behaviour. Focus question: Is there an increase in the perception and rating of disgust in females rather than males?

QAHS YEAR 11 Gender Differences in the Perception of Disgust Neurobiology and Behaviour Kayla Jackson TABLE OF CONTENTS TABLE OF CONTENTS page number DESIGN 3 1.1 Defining the problem 3 * Focus / research question * Hypothesis * Background information / theory * Investigation Variables 1.2 Controlling Variables 4 * Treatment of Controlled Variables * Control Experiment 1.3 Experimental Method 4 * Materials * Risk Assessment * Method 2 DATA COLLECTION and PROCESSING 5 2.1 Recording Raw Data * Quantitative Data * Qualitative Data 2.2 Processing Raw Data 6 * Statistical Processing - calculations 2.3 Presenting Processed Data 6 * Result (s) table (s) * Graph (s) * Graph (b) 3 CONCLUSION and EVALUATION 8 3.1 Conclusion * Conclusion statement * Conclusion explanation 3.2 Evaluation Procedures 9 * Reliability * Limitations / Weaknesses / errors in Laboratory Investigation * Significance of weaknesses on experimental results 3.3 Improving the Investigation 10 * Modifications to experiment BIBLIOGRAPHY 11 APPENDIX 12 Appendix One: Curtis et al, 2004. Paired disgust sensitivity stimuli and average disgust scores Appendix Two: Disgust Sensitivity by age and gender (Curtis et al. 2004) Appendix Three: QAHS STUDENT ACTVITY RISK ASSESSMENT and PRAC

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