ProblemWhat kind of roles the factors of pH levels and temperature have on various reaction rates. What roles inhibitors and activations play on enzymatic reactions.

John Sciullo Period-4 12-09-09 AP Lab 2 Enzyme Catalysis Abstract: AP Lab Enzymes, introduced us to the catalyzing proteins called, enzymes, focusing on the effects that various variables have on enzyme reaction rate. To further our knowledge of enzymes, we used a variety of chemicals to stimulate different conditions. Using sulfuric acid (H2SO4) we were able to stimulate an acidic environment. By boiling water in one part of the experiment, we were able to see the effects of temperature on reaction rate. Overall we tested a wide array of variables, investigating their effects on reaction rate. At the end of the experiment we were able to come up with the following viable conclusion; the variables that had the most significant impact on reaction rate had to do with changes in pH levels of the solutions, and the temperature. Splitting off into groups we began the lab by observing a reaction in which catalase was placed into a solution, releasing bubbles of O2. This reaction introduced us to enzymes and their activities. Shortly after, we began investigating the effects various variables had on the reaction rate. In demonstrating the effect of boiling on enzymatic activity, we were able to learn that sharply increasing the temperature of the enzymatic solution, the reaction rate lowered. As a group, we inferred that the high temperatures caused the enzymes,

  • Word count: 2663
  • Level: International Baccalaureate
  • Subject: Biology
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PROTECTION DE L'ORGANISME

PROTECTION DE L'ORGANISME Microbes : - Les Bactéries : o Appelées coque ou bacille o Se multiplient dans les liquides intérieurs riches en nutrients (ex : glucose) et en dioxygene - Les Virus : o 10 a 1000 fois plus petits que les bactéries o Appelé parasites o Parasitent nos cellules qui vont alors les multiplier ; les cellules meurent à la naissance des nouveaux virus. o Se transmettent par : * l'air * les aliments et la boisson * les liquides de l'organisme (sang, sperme, salive) * le toucher Protections : - Peau : o Constitue une barrière physique aux agents pathogènes o Accrue d'une protection chimique grâce a la sueur et d'une protection bactérienne - Muqueuses : o Respiratoire et digestives o Protégées par des secrétions de type : * Mucus * Acide o Empêchent les bactéries de se multiplier - Bonne hygiène corporelle, - la désinfection des places avec des antiseptiques (ex : alcool) limitent l'entrée des microbes dans nos corps - la stérilisation - Si attaqué par les bactéries, on peut utiliser des antibiotiques pour les tuer. Mes ceux ci sont sans action sur les virus. - SIDA : présent dans tout le monde et s'agit d'une pandémie comme MST (Maladies, Sexuellement Transmissibles). Seule l'utilisation d'un préservatif (condom) empêche sa propagation Réactions : - Après une blessure, apparaît

  • Word count: 798
  • Level: International Baccalaureate
  • Subject: Biology
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Reaction Time

Abstract The focus of this study was to investigate how the participation of different sports activities affects the reaction time. Two hypotheses were established based on my research question: "People who carry out sports should have a faster reaction time than those who do not" and "The sport where a fast reaction time is most important, thus where training sessions focus on improving it the most, should have a participants with faster reaction time than the sport where a fast reaction time is less important". The sports chosen were boxing, badminton, stationary bicycle, judo and swimming. A control group was included. In every group there were 20 participants where 10 subjects were women, 10 subjects were men, 10 subjects in the age group 10-17 and 10 subjects in the age group 18-40. The test was carried out using a reaction timer software installed on a laptop. The results showed that people who carry out sports do have a faster reaction time than people who do not. The average reaction time for people not carrying out sports was 0.305 seconds compared with 0.266 seconds that was the average reaction time for the slowest group of people carrying out sports, namely the people carrying out stationary bicycle. The investigation also revealed that the sport where a fast reaction time is most significant for winning a competition has participants with the fastest reaction

  • Word count: 5267
  • Level: International Baccalaureate
  • Subject: Biology
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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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  • Word count: 748
  • Level: International Baccalaureate
  • Subject: Biology
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Factors that affect the population size of an immobile population

* Al-Mashrek International School * School code: 2108 * Biology HL * Factors that affect the population size of an immobile population * Criteria: PL(A), PL(AB), DC, DPP, CE, * Bassam Al-Nawaiseh * 17/10/2007 Aim: the aim of this experiment is to study the effect of the effect of different light intensities on the growth of the pink clover (trifolium resupinatum) this is done using the quadrate method by defining two regions, region A and region B where both are squares with a side length of 10 meters. But region A is under a tree so the light intensity reaching the pink clover is low, while region B has nothing blocking the sun from it and so has a high light intensity reaching it. Now specific coordinates are specified in both regions and the quadrates are then placed at the place of the coordinates and the number of clover leaf inside them is counted then the total population is estimated using the following equation: Population size = mean number of organisms in region × total area Area of one quadrate Rationale: Plants need light for photosynthesis to occur. Photosynthesis is the production of food compounds from carbon dioxide and water by green plants using energy from sunlight, absorbed by chlorophyll i.e. Photosynthesis is how plants feed. lightlightlil 6CO2 + 6H2O C6H12O6 + 6O2 Plants use the light to break down the water molecule into oxygen

  • Word count: 893
  • Level: International Baccalaureate
  • Subject: Biology
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Why do we classify

There are multiple purposes for classifying. Classifying comes in handy when naming objects and groups of similar objects. This includes animate and inanimate objects. One also uses classification to help learn more about biology. For instance-if organisms are similar in some ways, they may be related or different in other ways; and by studying these similarities and differences, it gives us more biological understanding. Biological classification is a system in which all life on Earth is organized. The main objective of biological classification is to examine the relationships between various organisms. This allows for exploration into the origins of life on Earth. Two examples of biological classification would be the classification of humans and the red maple tree. When classifying these two organisms, they are standardized in a hierarchical system that goes from general to specific. When classifying humans, one starts with the Domain Eukaryota and works their works their way down to the subspecies sapiens. When classifying the tree, one starts with the Kingdom Plantae and goes to the species rubrum. In non-biological classification, inanimate and nonliving things are classified; and it is very arbitrary. Two examples are furniture and shoes. One can start classifying furniture by its shape, size, or even purpose; and shoes can be first sorted by color, material, or size.

  • Word count: 1155
  • Level: International Baccalaureate
  • Subject: Biology
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Biology Internal Assessment Peas Lab

Internal Assessment Biology: Respiration in Peas Purpose: In this laboratory, you will observe how respiration and decomposition produce heat in peas. Apparatus: Boiled peas (cooled to room temperature) Peas (not boiled) soaked in water Thermos Stopper fitted with thermometer Balances Labels Methods: .) Select a known mass of boiled peas (or a known number) and add them to the thermos 1. Fill the thermos approximately half full. 2.) Carefully label the thermos with your group name and what the thermos contains. 3.) Fit the stopper and the thermometer so that the thermometer bulb is immersed in the peas. 4.) Select the same mass (or number) of soaked, but not boiled peas and add them to thermos #2. 5.) Repeat steps 2-3 for thermos #2. 6.) Record the initial temperature of each flask. Both should be at room temperature. Continue to record the temperature of each flask at constant intervals (make sure to make at least 2 measurements per day) for several days. 7.) Once you have seen a temperature change in both flasks, open the flasks and observe their contents. Observe and notice if either of the flasks have peas that have sprouted and if either of the flasks have peas that have begun to decompose (ferment). Results Temperature (+/- 0,5 °C) Days Morning 8:10 Evening 4:10 Boiled Peas Not-boiled Peas Boiled Peas Not-boiled Peas Week-1 Monday

  • Word count: 1221
  • Level: International Baccalaureate
  • Subject: Biology
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Bacteria and Cleanliness. Question: Among the insides of a toilet, dishcloth, sink, and a refrigerator handle, what is the cleanest?

Pooja Mehta 4th period IB Biology -3-2010 Cleanliness Background: Bacteria are microorganisms that grow everywhere. We can collect and grow them in specially prepared Petri dishes. Blood agar or tryptic soy agar with 5% sheep's blood is an excellent medium for supplying bacteria with nutrients and an environment in which we can see them grow. Sterile powdered agar with nutrients can be mixed with water, heated and then poured into empty Petri dishes or ready-to-use dishes can be purchased. The indigestible agar is a gelatin-like substance with a semi solid surface on which the bacteria can grow while they consume the added nutrients (like sheep's blood). In fact, this is why gelatin itself does not make a good growing medium. Some bacteria can digest gelatin, which is a protein derived from animal tissue. This destroys the growing surface in the Petri plate making it unsuitable as a bacteria growth medium. CAUTION: Most bacteria collected in the environment will not be harmful. However, once they multiply into millions of colonies in a Petri dish they become more of a hazard. Be sure to protect open cuts with rubber gloves and never ingest or breathe in growing bacteria. Keep growing Petri dishes taped closed until your experiment is done. Then you should safely destroy the fuzzy bacteria colonies using bleach. Question: Among the insides of a toilet, dishcloth,

  • Word count: 1911
  • Level: International Baccalaureate
  • Subject: Biology
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Membrane Function practical

Membrane Function Planning A [Problem] Demonstrate the process of osmosis through a semi-permeable membrane. [Aim] To use a chicken egg as a model to demonstrate the process of osmosis [Hypothesis] The rate of osmosis increases, the concentration of the solution decrease. As we know the Osmosis is the passive movement of water molecules, across a partially permeable membrane, from a region of lower solute concentration to a region of higher solute concentration. So if the solute concentration idecreases, the rate of osmosis increases. Planning B [Variables] Independent variable The concentration of the solution (the egg goes in) Dependant variable The weight of the egg Controlled variable .the same electronic balance .the same egg .the same stop watch .the same spoon to help .the distilled water from same bottle .the same measuring cylinder .the same room temperature [Materials] . 1 egg which remove the shell already . Spoon . 300ml 10% NaCl solution . 300ml 5% NaCl solution . 300ml distilled water . 3 250ml bickers . Electronic balance . Stop watch . Paper towel .measuring cylinder [Method] Put the safety equipment on, such as the glasses and the apron. 2 Take the egg out of the plastic bag carefully use the paper towel to dry it carefully. 3 Place the egg on the balance and record its mass in the data table. 4 Use the

  • Word count: 1109
  • Level: International Baccalaureate
  • Subject: Biology
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COMPARATIVE INVESTIGATION LAB ON LICHENS

COMPARATIVE INVESTIGATION LAB ON LICHENS Design Research Question: Is there a significant difference calculated by the t-test to show that the percentage coverage of lichens found on the north side of the trees after one meter from the base of the tree be affected by the tree being either in the shaded or the sunny area? Variables: Dependent variable: - the number of lichens found on the trees. Independent variable: - trees found in the shaded areas and trees found in the sunny areas. Constant variable: - lichens found on the North side of the tress - lichens found after one meter from the base of every tree - the altitude at which the trees are looked at - the same soil type for all the trees - the surface of the trees not being too rough and very similar - the humidity of the area from where the trees are looked at - almost the same amount of sunlight reaching the trees in the sunny area - almost the same amount of sunlight reaching the trees in the shaded area - the amount of water available to the trees Hypothesis: Lichens produce their food from the sunlight with the help of its photosynthetic partner. It is more likely for lichens to grow on trees in large number in an area that has more sunlight compared to an area that is shaded. Therefore, the percentage coverage of lichen on the trees is going to be higher in an area with sunlight

  • Word count: 2608
  • Level: International Baccalaureate
  • Subject: Biology
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