The Role of Carbohydrates
The Role of Carbohydrates Carbohydrates are a very large group of molecules that can be synthesised by plants. They are molecules which contain carbon, hydrogen and oxygen atoms. Usually there is a ratio of 2:1 of hydrogen to oxygen atoms in a carbohydrate molecule. Carbohydrates are very common constituents of plants. They make up to around 90% of the dry mass of plants. Carbohydrates are also an essential part of the animal diet and they are usually obtained directly or indirectly from plants. The functions of carbohydrates vary greatly. There are many different carbohydrates with different sizes and structures, all of which perform a different task in plants or animals. Functions range from being an energy store to providing structural support and strength. There are three types of carbohydrates; they are the monosaccharides, disaccharides and polysaccharides. This division is based on the fact that polysaccharides are non-sugars whereas monosaccharides are simple sugars and disaccharides are compound sugars. Each group has its own distinctive properties and for every carbohydrate that falls under one group, they share a general formula. Monosaccharides are simple sugars and contain carbon, hydrogen and oxygen in the ratio 1:2:1 so every monosaccharide has the general formula (CH2O)n, where n can be any number between 3 and 9. They are small molecules with low molecular
Homeostasis & Control of BGL.
Homeostasis & Control of BGL Homeostasis Source - www.bbc.co.uk/schools/gcsebitesize/biology/humans/homeostasisrev1.shtml All the cells in our bodies are surrounded by a liquid called tissue fluid which has exactly the right conditions in which cells can work. Tissue fluid has the right temperature, the right amount of glucose and the right amounts of water and salt. Homeostasis is an important process that maintains these conditions at the right level. Source - http://pespmc1.vub.ac.be/ASC/HOMEOSTASIS.html A process of interaction which balances various influences and effects so that a stable state or a stable behaviour is maintained. Often that stable state or that stable behaviour is essential to assume structural stability of a SYSTEM. E.g., the size of the pupil of the human eye is negatively correlated with the intensity of light entering the retina thus keeping the amount of light within the limits of optimal processing of visual information. Too much light will destroy the light sensitive cones of the retina. The blood sugar content and many other chemical quantities are similarly balanced within the human body. In families, homeostasis may become pathological when family members no longer prefer that state yet cannot escape it as a consequence of the way they interact with one another (e.g., double bind). Source - http://pespmc1.vub.ac.be/HOMEOSTA.html
The main task of this experiment is to find out the concentration/volume of glucose present in samples of three different fruits. The fruits are fresh grapefruit, lemon and orange.
Biology Practical Assessment Skill Planning The main task of this experiment is to find out the concentration/volume of glucose present in samples of three different fruits. The fruits are fresh grapefruit, lemon and orange. Here is a table showing the different items that are to be used in the experiment. It also states the quantity and concentration and volume of each apparatus if appropriate. Item Quantity Concentration and volume Colorimeter N.A. Cuvettes 2 Hold up to 10mls Distilled water bottle 6ml Graduated pipette Holds up to 10ml Test tubes 8 Hold up to 27ml each Test tube rack N.A. Hot water bath N.A. Chinagraph pencil N.A. Coloured pencils (A range of different colours) N.A. Benedicts Solution bottle 320ml Glass rod N.A. 4% Glucose solution bottle Here is a table showing reasons for why the items listed were chosen and their application. Item Application Reason for choice Colorimeter To give absorbance readings for samples Most Suitable method of getting accurate, absorbance readings Cuvettes Used to put substances into, to put into colorimeter Standard apparatus used with the colorimeter Distilled water To dilute solutions Needed in the process of serial dilution to change concentrations of glucose 0ml graduated pipette To measure solutions accurately Most accurate and most suitable choice of measuring the
light on plant growth
An Investigation into the effect of Different Wavelengths Of Light on the Growth of Plants Pilot study data: The pilot study was designed to test which growth medium would be best for the cress, as well as the affect of different wavelengths of light on the plants growths. Method: All three of the containers had different colour films applied to them blue, green and red. The sides were covered in black sugar paper to prevent light other than the filtered light from passing through the cress. The blue film container had cotton wool as the growth medium. The red container had Perlite as its medium and the green container had filter paper as their media. The containers were all placed in the same location and had enough water throughout the experiment. The plants were measured using a ruler. Ten seeds were planted per container. The cress plants were measured daily and watered as necessary. The accuracy and precision of this experiment was maintained by using a millimetre-graduated ruler, as it was appropriate to measure cress in millimetres. The reliability of this study was ensured, by using replicates in the form of ten seeds per container rather than just the one seed per container. Pilot hypothesis: I hypothesise that the cress will grow to a greater maximum height under blue and red light than they will under green light. I also hypothesise that the greatest
To investigate the effect of sucrose solution on osmosis.
Elliot Smith 15th October 2001 AT1: Osmosis AT1: To investigate the effect of sucrose solution on osmosis. Aim: Osmosis is the change of water from a weak solution to a strong solution. We are going to try and establish osmosis in potato chips by using different concentrated sucrose solutions with H2O (water): 0.0 mol sucrose 0.2 mol sucrose 0.4 mol sucrose 0.6 mol sucrose 0.8 mol sucrose .0 mol sucrose Prediction: If I changed the amount of sugar I predict that the potato will be lighter because osmosis will be increased. If I changed the amount of light, then I predict that nothing will happen because osmosis does not need light. If I change the volume of sucrose in the water, I predict that the more sucrose present, the lighter the potato. I have chosen to change the volume of sucrose. Apparatus: 6x test tubes 4x potatoes 1x bore 1x scalpel 1x pepite 1x ruler 1x scales 6x different concentrated solutions Method: I am going to try and effect osmosis by using different concentration levels in six different test tubes. I am doing this experiment in room conditions. Potatoes must be cut very carefully to get a correct result. I shall cut 6x5cm bars using a scalpel to cut and a ruler to measure. Then I shall number each bar, 1, 2, 3, 4, 5, or six. I shall then number each test tube in the
Drinks For Diabetics
James MacDonald Drinks For Diabetics Introduction: Glucose is a reducing sugar commonly found in food and drink. It is one of the few molecules to be absorbed rapidly through the stomach wall (water and alcohol are others). Diabetics have little or no control over their blood glucose concentration and it may suffer a rapid increase after eating or drinking. This increase causes a change in blood water potential and harmful increases in blood pressure. The amount of glucose in solution can be determined using Benedict's reagent, an alkaline copper solution that reacts with the reducing carbonyl group (C=O) in some carbohydrates. All monosaccharides and the disaccharides maltose and lactose are reducing. The concentration of reducing carbohydrate can be determined from standard solutions of known glucose concentration. Aim: To carry out an experiment to determine which drinks would be safest for a diabetic person to drink without them having to worry about insulin levels. Apparatus: Benedict's Solution Test Tubes Boiling Water Bath Syringe Drinks to test Solutions of various sugar concentrations Variables: Temperature Concentration Ratio of Benedict's solution to drinks Method: First, 2ml of various drinks and sugar concentrations were put into test tubes using a syringe. 1ml of Benedict's was put into each test tube and mixed. All the
AN ACCOUNT OF NITROGENOUS EXCRETION IN MAMMALS Excretion is the disposal of the waste products of metabolism, example ammonia and urea from
AN ACCOUNT OF NITROGENOUS EXCRETION IN MAMMALS Excretion is the disposal of the waste products of metabolism, example ammonia and urea from deamination of amino acids and disposal of substances present in excess e.g. water, salts. Excretion is the elimination of the unwanted products of metabolism and of metabolites present in excess within the organism. Animals excrete nitrogenous waste products such as ammonia, urea or uric acid. These or similar products are produced by the deamination of any excess protein that has been eaten. Nitrogenous compounds are formed in metabolism of proteins and nucleic acids. Ammonia is lost by diffusion from small aquatic organisms, urea is excreted by organs of nitrogenous excretion example the kidney. Excretion involves eliminating any excess or toxic substance taken in with the diet, including water and salts. Excretion plays an important part in the process by which the internal environment is regulated to maintain more or less constant condition (homeostasis). Green plants do not excrete nitrogenous waste; on the contrary, they re-use any breakdown products of nitrogen metabolism. Excretion in animals is mainly concerned with nitrogenous waste, and to a less extent with other waste products of metabolism. The three compounds of importance in nitrogenous excretion of animals are ammonia, urea and uric acid. The amino group being removed
FUNDAMENTALS OF ATATOMY AND PHYSIOLOGY
Epithelial tissues Epithelia are the linings of internal and external surface and body cavities, including ducts carrying secretion from glands. They are composed of several layers of cells called epithelia or just a single layer known as simple epithelia. The lowest or the bottom layers of cells are attached to a basement membrane for support and connection. The basement membrane is secreted by the epithelial cells. There are nerve supplies to epithelia but they are supplied with oxygen and nutrients from deeper tissues by diffusion. As they are surface tissues and exposed to fraction, their capacity for growth and repair is grater than other tissues and usually occurs during sleep. Simple epithelia Simple epithelia serve many roles in various body locales. As components of serous and synovial membranes, simple epithelia secrete fluids that lubricate tissues to minimize friction as organs or other body structures rub against one another. Other simple epithelia line body tracts as protective, absorptive, or secretory cells. All glands of the body are constructed of epithelial cells as are the ducts that connect the exocrine types to body surfaces. As linings in the alveoli (air sacs), kidneys, and blood vessels, simple squamous types assist in diffusion, osmosis and filtration phenomena. As linings and covering on all external and internal body surfaces, epithelia serve
Optimal Conditions For Everyday Enzymes
Name: Alec Cooke Partner: Andrew McDermott Experiment Date: March 5, 2009. Lab 1: Optimal Conditions For Everyday Enzymes Meat Tenderizer and pH Due Date: March 12, 2009. Instructor: Mrs. Robertson Introduction Enzymes are proteins that speed up reactions in living systems by lowering the activation energy of these reactions, without changing the outcome of the products. A protease is a type of enzyme that specializes in the breaking down of complex polypeptide bonds, such as the ones in gelatin. Flavour and colour molecules are trapped in the gelatin by its helical structure. When an enzyme breaks down gelatin, the colour and flavour molecules are released. The amount of colour or flavour released by the gelatin can be quantitatively analyzed to determine the efficiency of the enzyme. Since flavour is hard to test for, the enzyme will be tested using only the amount of colour released by the gelatin. Enzymes will be mixed with gelatin in seven different environments with constant temperatures, but different pH levels, ranging from very acidic (1) to very basic (13). The amount of colour released by the gelatin in each environment will then be tested by a spectrophotometer. The results will show how well the enzyme functions in the varying levels of pH. Purpose The purpose of this lab is to investigate the effect pH has on the efficiency of an enzyme, and to
Describe the molecular structure of starch (amylase), glycogen and cellulose, and relate these structures to their functions in living organisms.
Describe the molecular structure of starch (amylase), glycogen and cellulose, and relate these structures to their functions in living organisms. Carbohydrates are the main energy source for the human body. Chemically, carbohydrates are organic molecules in which carbon, hydrogen and oxygen bond together in the ratio: Cx(H2O)y where x and y are whole numbers that differ depending on the specific carbohydrate to which we are referring. Animals (including humans) break down carbohydrates during the process of metabolism to release energy. For example, the chemical metabolism of the sugar glucose is shown below: C6H12O6 + 6 O2 6 CO2 + 6 H2O + energy Animals obtain carbohydrates by eating foods that contain them, for example potatoes, rice, breads, etc. These carbohydrates are manufactured by plants during the process of photosynthesis. Plants harvest energy from sunlight to run the reaction described above in reverse: 6 CO2 + 6 H2O + energy (from sunlight) C6H12O6 + 6 O2 A potato, for example, is primarily a chemical storage system containing glucose molecules manufactured during photosynthesis. In a potato, however, those glucose molecules are bound together in a long chain. As it turns out, there are two types of carbohydrates, the simple sugars and those carbohydrates that are made of long chains of sugars - the complex carbohydrates. In this essay I am going to
