food groups present in chemcial testina
An experiment to discover the types of food groups present in food using chemical testing. Introduction Carbohydrates are organic molecules that contain 3 elements carbon, hydrogen and oxygen. The two types of carbohydrates that are being investigated in this experiment are sugars and starches. There are three basic types of carbohydrate molecules that are form its structure, these are: * Monosaccharides - which are single sugars. * Disaccharides - double sugars made from two monosaccarides. * Polysaccharides - multiple sugars (polymers of many monosaccarides). Carbohydrates have several functions and roles within the human body, for example, starches are ideal for storage and sugar is ideal for energy. As well as being vital in structural components, a good example is connective tissue, chitin in crabs and cellulose. Lipids or more commonly known as waxes, fats and oils are non - polar molecules. Most are insoluble in water but are soluble in non - polar solvents such as alcohol. Lipids contain several elements, carbon, hydrogen, oxygen and sometimes nitrogen and phosphorus. When testing for lipids - food should be cut up into small pieces and mixed with pure ethanol, which is then shaken. If lipids were present they would dissolve in the alcohol. By removing some of the solution and mixing it with water, a portion of the solution would turn white, with a small
Which antibiotic is most effective?
Hypothesis: There will be a zone of inhibition around the antibiotic on the agar plate due to the antibiotic inhibiting the growth of microorganisms (such as bacteria). In this case it can be seen that the antibiotic A is far more successful in killing the bacteria than B. This is evident as the diameter of the inhibition zone of A, shown by the arrow, is far larger than that of the inhibition zone of B.1 Increasing the concentration of a bactericidal antibiotic such as penicillin should increase the number of bacterial colonies it kills. Apparatus: * Agar plate seeded with known Bacteria * Sterile Pasteur pipette * Bunsen burner * Beaker of disinfectant, 1% Virkon or equivalent * Bench spray of disinfectant, 1% Virkon or equivalent * Bactericidal soap * Paper towels * Marker pen * Forceps * Mast ring or antibiotic impregnated paper discs * Adhesive tape * Incubator set at 30 °C Method: . Wash your hands with the bactericidal soap. Spray the working area thoroughly with the disinfectant spray and wipe with a paper towel after waiting for the disinfectant to act. 2. Prepare an agar plate seeded with bacteria. This may have already been done for you. If not, follow the instructions on the Student sheet 'Pouring agar plates' which can be found with Activity 4.19. Label the Petri dish on the base at the edge with your name, the date, and the type of
Describe what happens to saccharide units in starch when taken in by the mouth for digestion until the assimulation into muscl
Describe what happens to saccharide units in starch when taken in by the mouth for digestion until the assimulation into muscle cells. Starch is a polymer of glucose (a saccharide unit). Amylose starch molecule. Polysaccharides are formed when many hundreds of monosaccharides units condense to form chains. These chains of monosaccharides may be: * Of a variable length, although usually at a greater length. * Branched or unbranched * Folded so that the molecule is "compact" and ideal for storage, e.g. starch and glycogen. * Straight or coiled - good for construction. Most of the important polysaccharides are made from hexose units, so are called hexosans. Many are made from glucose itself. So are called glucosans. Glucose units can from long chains in three ways. Amylose and cellulose are completely straight. Starch is a mixture of both amylose and amylopectin. Glycogen is amylopectin with very short lengths between its branches. Digestion involves the breakdown of large, insoluble food molecules into smaller, soluble compounds, which can be absorbed. For example, starch is broken down into smaller monosaccharides and disaccharides; proteins are broken down into polypeptides, then into tripeptides, dipeptides and finally amino acids. Human digestion begins with physical digestion - the action of teeth chewing or mastication. This is when the mouth takes in the
Investigation into Catalase
Biology SC1 Investigation Catalase Investigation Background Science Catalase is an enzyme found in all living cells. It makes Hydrogen Peroxide decompose into water and oxygen. You can represent this in the equation: 2H2O2 =2H2O + O2 Enzymes: Enzymes are able to increase the rate of reaction without actually being consumed in the process. In all, enzymes are very efficient. Small quantities at low temperatures are able to produce results, which would require high temperatures and a violent reaction from any normal chemical means. Although increases in temperature may speed up the reaction, enzymes are unstable when heated. There are three important definitions that are used when talking about enzymes: - The substance that enzymes act on is the substrate. The substance formed by the reaction is the product The site on which the enzyme takes place is called the active site. Enzyme function can be explained by the Lock and Key Hypothesis: the active site of an enzyme (the lock) has a specific shape in which only the precise amount of substrate (the key) will fit - forming an enzyme-substrate complex. Therefore producing a product. All enzymes have the following 4 properties: * All enzymes are proteins * Enzymes are catalysts * Enzymes are denatured by high temperatures * Enzymes work best at a certain pH (normally 7) The Effect of Enzyme concentration: As long
Investigate the effect of pH on Trypsin
Biology Coursework Plan Aim Investigate the effect of pH on Trypsin Prediction / hypothesis * pH will affect trypsin action * as pH increases, tryrpsin will show increasing activity up to an optimum pH * the action of the enzyme trypsin on the substrate egg albumen will be at a maximum at an optimum pH of around 7 (neutral) to 8 (slightly alkaline) see later about pH of duodenum * as pH continues above this, trypsin activity will decrease Background / Introduction Proteins are complex organic compounds consisting of amino acids joined by peptide bonds which form highly folded three dimensional or tertiary structures. The bonds that maintain the tertiary structure of the protein are a result of interactions between the R groups of the amino acids: disulphide bridges (strong covalent), hydrogen (weak) bonds, ionic or electrovalent bonds, hydrophobic interactions. Enzymes, such as trypsin, are globular proteins with a specific shaped active site into which the correct substrate can fit. trypsin protein / polypeptide peptides Trypsin is a protease enzyme: a hydrolytic or digestive protein that cleaves peptide bonds. It is produced in the pancreas in the form of trypsinogen, and is then transported to the duodenum of the small intestine, where the digestion of proteins to polypeptides and amino acids begins. The pH
Industrial uses of enzymes
Industrial uses of enzymes Most of the reactions catalysed by enzymes have commercial or industrial uses. These reactions used to happen by using high heats or strong acids but no enzymes can be used in these industrial processes. Here are just a few ways they can be used. Biological washing powders use the enzyme protease. This is enzyme is used to break down protein stains for example food and blood. The enzymes need alkali conditions to work there best and the detergents provide this. And as the enzymes work at relatively low temperatures this means the washing machine does not have to work at high temperatures. This is one advantage to using enzymes in biological washing powder. This is an economic advantage because the washing machine is not using, as much heat so it will not be using as much energy and this will be saving on the cost of your electric and heating bills and the cooler the temperature the kinder it is to your clothes so they last for longer. It's also an environmental advantage because it does not need to be so hot so less fuel is used. A disadvantage to using enzymes in biological washing powder is that some people become extremely allergic to the free enzyme, so to solve this problem before the enzyme is added to the other ingredients in the washing powder it is coated in wax. This wax makes the enzyme dust free and so it is only released in the wash.
Tests for carbohydrates practical
Results Non - Quantitative Test for reducing sugars (1, 2, and 3) Test for Non-reducing sugars (4, 5, and 6) Test Tube Number Sugar Initial Colour Final Colour Glucose Blue Brown/Red 2 Sucrose Blue Blue 3 Starch Blue Blue 4 Glucose Blue Brown 5 Sucrose Blue Brown 6 Starch Blue Blue Test for Starch Iodine colour = Red/Brown Iodine added to solution = Blue/Black The when boiling goes = Colourless Then when cooled = Blue/Black Questions ) Explain fully of all the tests? a) Non - Quantitative Test for reducing sugars All three test tubes initial colour is blue. This blue comes from the Benedict's solution as it is made up of Copper Sulphate (which gives it the blue colour) and Sodium Hydroxide (used to make the solution alkali) which is colourless. When the Benedict's reagent is added to test tube 1 (glucose) and heated it produces a copper oxide precipitate, this is because glucose is a reducing sugar due to it being able to change Cu 2+ to Cu+ forming the copper oxide precipitate. The colour of copper oxide is a rusty brown/red colour (final colour). In test tube 2 when Benedict's reagent is added the colour is blue also. It does not reduce the copper sulphate as the bonds between the fructose and glucose have not been broken and therefore sucrose remains to be sucrose and therefore not a reducing sugar. Test tube 3 (Starch) is also
Investigating The Effect Of Temperature On Plant and Fungal Amylases
Investigating The Effect Of Temperature On Plant and Fungal Amylases Enzymes are biological catalysts responsible for catalysing metabolic reactions. They increase the rate of reaction. Amylase is an enzyme which catalyses the hydrolysis of poly/disaccharides into monosaccharides. Temperature affects how quickly the enzyme catalyses the breaking up of the substrate (what the enzyme is breaking down). It increases the rate of reaction (amount of substrate which is converted to product per unit time). The reason for this is because at higher temperatures the molecules have increased kinetic energy than at lower temperatures. With increased energy, they are more likely to bump into each other and it is more likely that the substrate and active site will collide and react to produce a product. When the molecules do collide, there is increased chance they will overcome the activation energy barrier. This is the energy needed to start the reaction. At very high temperatures the enzyme ceases to work. This is because enzymes are proteins and become denatured at high temperatures. The high temperatures cause the hydrogen bonds and hydrophobic interactions to break, which changes the shape of the enzyme. At a different shape the enzyme can no longer hold the substrate. As the temperature increases even more the whole protein becomes completely denatured. The reaction stops. At
The Cell membrane surrounds all living cells and is the most important organelle, there is also a similar plasma membrane that surrounds all the organelles except for the ribosome.
The Cell membrane surrounds all living cells and is the most important organelle, there is also a similar plasma membrane that surrounds all the organelles except for the ribosome. The membrane controls how and what substances can move in and out of the cell/organelle The structure of the membrane is often referred to as the "Fluid Mosaic Model"; this is because of the way it is structured It is composed of phospholipids, proteins, and carbohydrates, which are arranged in a fluid mosaic structure. The phospholipids are arranged in a "bilayer". With their hydrophilic (water attracting) phosphate heads facing outwards and their hydrophobic (water fearing) tails facing in towards the middle of the bilayer. The hydrophobic layer acts as a barrier to all but the smallest molecules and effectively isolating the two sides of the membranes. Some membranes contain phospholipids with different fatty acids, which affect the strength and flexibility. Animal cells also have cholesterol linking the fatty acids together and so stabilising and strengthening then membrane The proteins usually span from one side of the bilayer to the other. These are called integral proteins. But some sit on one side of the bilayer, these are called peripheral proteins. Proteins comprise approximately 50% of the mass of the membrane. The integral proteins (ones which span across the whole bilayer)
The human digestive system.
The Human Digestive System The Mouth Chewing makes a larger surface area of the food for the enzymes in the mouth to attack. The Small Intestine How is the structure of the wall of the ileum (small intestine) adapted to its function in the absorption of the products of digestion? * Large Surface area * Moist surface * Thin (epithelial) surface/ short absorption pathway * Long/ folds (increasing surface area) * Villi * Microvilli * Longer intestine * Lacteal * Capillary network in villus/ good blood supply * Mitochondria to supply ATP/ energy for transport * Carrier proteins in membranes. * Maltase is produced in the small intestine Sugar Absorption in the small intestine * Diffusion in capillaries * Active transport/ facilitated diffusion involved * ATP used by active transport * Disaccharides/ enzymes in cell surface membrane * Glucose/ monomers/ monosaccharides actively transported into epithelial cells via protein carriers/ channels (in membrane) * Facilitated diffusion from epithelial cell/ towards blood enzymes and digestion in humans. enzymes different enzymes are required for the digestion of different food substances. for example amylase can only digest starch. it cannot digest protein, carbohydrates or lipids. this is because each type of food substance has a particular shape. since enzymes can only function if they have a particular
