Cell Theory - Discuss the theory that living organisms are composed of cells.
IB Biology Syllabus Unit 1 .1 Cell Theory (3h) .1.1 Discuss the theory that living organisms are composed of cells. .1.2 State that a virus is a non-cellular structure consisting of DNA and RNA surrounded by a protein coat. A virus is a non-cellular structure consisting of DNA and RNA surrounded by a protein coat .1.3 State that all cells are formed from other cells. All cells are formed from other cells .1.4 Explain three advantages of using light microscopes. * Colors of material from specimen can be seen * Living material can be studied and larger field of view * Cell activities and movement can be studied .1.5 Outline the advantages of using electron microscopes. Electron microscope * Greater resolution so smaller structures can be seen * gives interior/3-D view .1.6 Define organelle Organelle - a small body with a specialized structure within a cell for a specific function .1.7 Compare relative sizes of molecules, cell membrane thickness, viruses, bacteria, organelles and cells, using appropriate SI units. Size comparison: * molecules - 1 nm * macromolecules - 100 nm * cell membrane - 10 nm * virus - 75 nm * bacteria - 1 ' m * organelle - 3 ' m * cell - 10 ' m .1.8 Calculate linear magnification of drawings. Magnification = size of image / size of specimen .1.9 Explain the importance of the surface area to volume ratio as a factor limiting
F336- aspirin individual Investigation
Does Temperature Affect The Yield And Purity Of Aspirin? Contents Objectives ) Research using various sources on aspirin with reference to; history ,use in medicine and methods of synthesis 2) produce a sample of aspirin using a method found during research 3) Verify the presence of aspirin and use various method to measure the purity of the manufactured aspirin 4) Carry out investigation to see if temperature effects the yield and purity of aspirin Research History of aspirin 400 BC, Greece - Hippocrates recommended a brew made from willow leaves to ease the pain of child birth. 763, England - A reverend called Edward Stone was walking through a meadow in Oxfordshire while suffering from an acute fever. Stone removed a small piece of bark from a willow tree and nibbled on it. He was struck by its extremely bitter taste, as an educated man he knew that he bark from Peruvian cinchona tree (which has a similar taste) is used in the treatment of malarial fevers. He surmised that the willow might also have therapeutic properties. He gathered and dried a pound of willow bark and created a powder which he gave to about fifty people. It was consistently found to be a "powerful astringent and very efficacious in curing agues and intermitting disorders". He had discovered salicylic acid, the active ingredient in aspirin. 1828, Germany- Johann Büchner isolates pure
Serving Newton
CHAPTER FOURTEEN SERVING NEWTON At the start of the year's University Physics 1 degree course, the Physics Professor looked at the motley crew filling the lecture theatre. He knew some students were destined to survive, while others would drop-out. In a rather callous way, the professor wrote-off the previous twelve years of the students' scientific education before introducing the course. Writing on the board just four symbols, he continued saying "The single most important equation in the Universe is," " F = m a " The experience could be likened to watching the rector at church, singing the praises of the most exalted one. "From this equation" he said, "everything else, all other forces are derived, forces including motion, gravity, electrostatics and magnetism. This can be experimentally proven over-and-over again as a Law of Nature, as a Universal truth. " But this was no rector, this was the bishop, the professor himself outlining Newton's laws of motion, showing the magic relationships that exist in the sciences. The Universe seemed to make sense at that moment, but then his reverent attitude turned. He introduced into this overview scheme of things, three body gravitational systems. At this point, he stated that Newton's laws failed, for "this is where Einstein's approximations come into their own, for only they can accurately predict and solve the forces that
WHAT EFFECT DOES SUBSTRATE HAVE ON THE RATE OF RESPIRATION IN SACCHAROMYCES CEREVISIAE?
WHAT EFFECT DOES SUBSTRATE HAVE ON THE RATE OF RESPIRATION IN SACCHAROMYCES CEREVISIAE? Aim: To investigate the effects of different types of substrates on the rate of respiration of Saccharomyces Cerevisiae by measuring the volume of CO2 produced using a gas syringe Background information What is respiration? Respiration is the name given to the biological process which occurs in all living cells. It involves the release of energy, by oxidising glucose. Glucose is a carbohydrate, specifically a monosaccharide, which undergoes a series of reactions releasing energy which the cell uses. Every cell needs energy and thus every cell respires to release the energy that it needs. However, respiration consists of many stages. These stages are glycolysis, the link reaction, the Krebs cycle and finally, the electron transport chain. These are explained in detail below: C6H2O6(aq) + 6 O2 (g) --> 6 CO2 (g) + 6H2O(l) + energy Glucose + Oxygen --> Carbon dioxide + water + energy Glycolysis: a process in which a 6C sugar, usually glucose, is split into 2 pyruvate molecules, which are a 3C acid. The process takes place in the cytoplasm of the cell and is summarised in detail below. Glucose, like many sugars is very unreactive and therefore needs to be activated. Therefore it is converted into a more reactive hexose sugar, fructose bisphosphate by adding 2
Investigating how concentration affects rate of reaction
Investigating How Concentration and Temperature Affect the Rate of Reaction Aim I aim to investigate how the concentration of potassium bromide affect the rate of reaction when added to a solution made up of potassium bromate(V), sulphuric acid and phenol. The general equation for the reaction between bromide and bromate ions in acidic aqueous solution is: (1) BrO3-(aq) + 5Br -(aq) + 6H+(aq) 3Br2(aq) + 3H2O(l) I am going to alter the concentrations of potassium bromide, potassium bromate and sulphuric acid to find the orders of reaction with respect to each reactant. This will allow me to prove that the rate equation for this reaction is: (1, pg 230) Rate = k[BrO3-][Br -][H+]2 I will be working out a value for the rate constant, k, and will also be investigating the affect temperature has on rate of reaction, using my results and the Arrhenius equation to work out the activation enthalpy. Theory: The colour change in this reaction is from an orange, brought about by the methyl orange indicator, to a colourless solution. As bromine is produced in the reaction it, at first, bonds to the phenol. However, when all binding sites on phenol have been used up, the presence of excess bromine will turn the solution colourless. This shows that I am measuring the time taken for all binding sites on phenol to be used up, which explains the change
A Level Biology revision notes
Balanced Diet * Energy Balance o Energy is obtained from food * Main energy from carbohydrates (glucose) and fats * Proteins are used for growth and repair first * Excess proteins is converted to energy o Out of balance * More energy/food than required › obesity * Less energy/food than required › starvation o Types of carbohydrates * Intrinsic sugars: found within cells (fruits) * Extrinsic sugars: sugars that have been added to food (processed food) * Milk sugars: found in milk products * Basal Metabolic Rate (BMR) o Energy needed at rest (not when asleep!) for routine tasks of cells (excrete waste) o Factors that influence BMR * Age * Young > Old * Growth requires more energy › children, pregnant women (fetus) * Young and active people have more muscles than older people * Sex * Male > Female * Women have more adipose than muscle tissue * Muscles (work out) require more energy than fat cells (storage) * Body size * Tall and thin > short and obese * Tall and thin people have a large surface area but small volume * Loose heat quicker * Need more energy to maintain body temp * High body mass > Low body mass * High body mass › more cells that require energy * Starvation o No carbohydrates and fats are available in the diet o Body starts to break down its own proteins (muscles) Function of Fibres * Polysaccharides (cellulose) that
The effect of Electromagnetic Fields on Enzyme Activity
THE EFFECTS OF ELECTROMAGNETIC FIELDS ON ENZYME ACTIVITY Silvia Panico Monday, September 17, 2001 Word count: 9661 AIM: To observe and determine the effects of an electromagnetic field of low frequency on enzyme activity THEORY / PREDICTION: An important topic which is very discussed in today's society is the effect of electromagnetic radiation or fields on the human body. A great amount of research has been done in this field all of which has ended up in conflicting results, and all wraps up to one conclusion: the evidence isn't enough to declare electromagnetic fields dangerous or beneficent to the human body. To further explore this area we will first need to observe the nature of electromagnetic fields and separately the one of enzymes to then decide the results of the two clashing together. The electromagnetic spectrum includes waves, or radiation, of all frequencies. The higher ones are properties of gamma rays and x-rays, these have also a very short wavelength, and they are know to be very dangerous to the human body because they are
Investigate the effect of bile salt concentration on the digestion of milk by the enzyme lipase.
Biology Coursework Investigation into the effect of bile salt concentration on the digestion of milk by lipase Seham Akkad 13I Skill P - Planning Aim: Investigate the effect of bile salt concentration on the digestion of milk by the enzyme lipase. Background knowledge: Bile: In humans about 1000 cm3 of bile is produced each day. In the body, bile is synthesised in the liver, from cholesterol, by hepatocytes. The bile is then concentrated and stored in the gall bladder ready to be secreted into the bile ducts, travelling into the small intestine making the conditions alkaline. Bile salts have two main roles; emulsification of dietary lipids and transport of lipids in a water soluble environment. The emulsification of lipids involves breaking down the large fat globules into smaller droplets increasing the surface area to volume ratio, as well as allowing lipases to access the lipids inside the droplets. As bile salts are made from cholesterol, the are involved in the transport of lipids around the body in the form of micelles, were the hydrophilic areas point outwards and the hydrophobic areas point inwards encasing lipids such as triglycerides, and allowing them to be transported. Bile salts also allow the transport of lipid soluble vitamins in the bloodstream. http://arbl.cvmbs.colostate.edu/hbooks/pathphys/digestion/smallgut/absorb_lipids.html
Comprehensive and Detailed Chemistry notes
. MUCH OF THE WORK OF CHEMISTS INVOLVES MONITORING THE REACTANTS AND PRODUCTS OF REACTIONS AND MANAGING REACTION CONDITIONS * outline the role of a chemist employed in a named industry or enterprise, identifying the branch of chemistry undertaken by the chemist and explaining a chemical principle that the chemist uses * identify the need for collaboration between chemists as they collect and analyse data Chemists usually work in teams. The needs for collaboration are: - The sharing of expertise. Not all chemists work in the same field. - There is a wider knowledge available - Incraeses validity and acuuracy of data and results - Time is saved since data is gathered and analysed in teamwork * describe an example of a chemical reaction such as combustion, where reactants form different products under different conditions and thus would need monitoring Once a reaction takes place, it is important to monitor the reaction. This is because if conditions in the reaction chamber are altered, harmful products may be produced and reaction wouldn't go to completion. Eg: Incomplete combustion - Incomplete combustion of octane: C8H18(l) + 9O2(g) › 3CO2(g) + 3CO(g) + 2C(s) + 9H2O(g) - CO is a poisonous gas which combines strongly with haemoglobin preventing transport of oxygen - Carbon is a pollutant and forms soot - Incomplete combustion occurs in poorly started
An investigation to examine the effects of temperature on membrane stability in beetroot, by assessing the degree of pigment leakage.
An investigation to examine the effects of temperature on membrane stability in beetroot, by assessing the degree of pigment leakage. Aim: - to discover how temperature affects the stability of the cell membrane in beetroot. Introduction:- Plant cells contain a plant cell wall as well as a cell membrane, which surround the protoplast (everything that is within the cell) of the cells. All cell membranes consist of a phospholipids bilayer, which are made up of two layers of phospholipids, hence the name. The plasma membrane is a partially permeable barrier between the cell and the extra cellular environment. The plasma membrane mainly consists of phospholipids. These phospholipids are a phosphate head, which is attached to two fatty acid tails (hydrocarbon chain). The phosphate group is highly soluble in water and so hydrophilic; however, the fatty acid tails are not soluble in water and therefore are hydrophobic. In the plasma membrane, the phospholipids are in two layers (hence the name phospholipid bilayer). The hydrophobic regions of the phospholipids line up together in the middle of the membrane, whilst the hydrophilic regions are on the outside of the membrane. Due to the hydrophobic regions of the phospholipid bilayer, it is generally not possible for large charged molecules or ions to pas through the membrane freely. The phospholipids have a hydrophilic (water
