Homeostatic Control of Blood Glucose Levels
Adnan Undre Homeostatic Control of Blood Glucose Levels Glucose is an essential substance in the body as it the primary source of energy for all biological functions and is indeed the only form of energy which can be used by the brain and central nervous system. The ideal level of blood glucose is 80 - 90mg of glucose per 100mls of blood. However this level is not static - it oscillates due to changes in the body which are brought about by actions such as eating a meal, exercising, or not eating for long periods. If blood glucose levels drop or rise dramatically there may be serious consequences such as hypo- or hyperglycaemia which can both cause death. Thus it is necessary for blood glucose levels to be regulated and this is achieved through homeostasis. To work effectively homeostasis requires an effective receptor to detect variations from the norm and a negative feedback system where antagonistic processes work to redress any variations as they occur. By examining the mechanisms of the homeostatic control of blood glucose levels it should be possible to explore the consequences of a breakdown of this part of the endocrine system. Essentially, blood glucose levels are controlled by the pancreas. It is in this organ that areas of cells called the Islets of Langerhans exist, which consist of alpha cells and beta cells. These cells monitor blood glucose and secrete the
Investigate the effect of altitude training on the density of blood.
An Investigation to find out the Effect of Altitude Training on the Density Mock Blood Rikin Patel Candidate Number- 1110 Centre Number- 63255 Aim The aim of this coursework was to investigate the effect of altitude training on the density of blood. Introduction Red blood cells, also known as Erythrocytes, are the most common type of blood cell and are a body's principal means of delivering oxygen to body tissues via the blood. The other type of blood cells in the blood are the white blood cells, which are actually immune cells. Red blood cells deliver oxygen via hemoglobin, a complex molecule containing four haem groups that temporarily link to oxygen molecules in the lungs and release the oxygen throughout the body. Hemoglobin also carries a waste product, carbon dioxide back from the tissues. Red blood cells consist of almost 90% hemoglobin; the heme is what gives blood its red colour. Myoglobin is similar to haemoglobin, but acts as a store for oxygen in muscle cells. Human red blood cells have a flattened ovate shape, depressed in the center. This shape is used because it optimizes for the exchange of oxygen with the surrounding cells. The cells are flexible so as to fit through tiny capillaries, where they release their oxygen. The diameter of a typical red blood cell is 6-8 µm. Below is a diagram of a red blood cell: Red blood cells are continuously being
A Colorimetric Method for the Estimation of Glucose in Solution.
A Colorimetric Method for the Estimation of Glucose in Solution Method A clean pipette was used to transfer 10cm of 10% glucose into a boiling tube. The pipette was then used to transfer 9cm of 10% glucose into a different boiling tube. 1 cm of distilled water was added to give 10cm of 9% glucose. This was repeated to make 10cm of 8%, 7%, 6%, 5%, 4%, 3%, 2%, and 1% glucose solutions (use the table below to help): Concentration of glucose (%) Volume of 10% glucose to transfer (cm ) Volume of distilled water to transfer (cm ) Total volume of solution (cm ) 0 0 0 0 9 9 0 8 8 2 0 7 7 3 0 6 6 4 0 5 5 5 0 4 4 6 0 3 3 7 0 2 2 8 0 9 0 A clean pipette was used to transfer 5 cm of 1M sulphuric acid into each solution. A clean pipette and pipette filler was used to transfer 2cm of potassium permanganate solution into each boiling tube. A stopwatch was started the exact moment the potassium permanganate was added to the acidified glucose solutions. A time was recorded, in seconds for the complete decolourisation of the potassium permanganate solutions. Results Concentration of glucose (%) Start time (seconds) Finish time (seconds) Elapsed time (seconds) 0 90 562 472 9 80 578 498 8 70 590 520 7 60 605 545 6 50 614 564 5 40 629 589 4 30 635 605 3 20 963 943 2 0 787 777 0 2486 2486 Results of
Investigating effect of changing glucose concentration on respiration in yeast
Investigating the Effect of a Variable on the Rate of Respiration in Yeast Method . Make a yeast solution with the yeast concentration of 20% by mixing 4 parts water with 1 part powdered yeast. 2. 20cm3 of this is added to a conical flask 3. Now, add 10cm3 of water and the appropriate amount of glucose 4. Keep the contents of the conical flask at a constant temperature (40c) using a water bath. 5. Use a glass gas syringe to measure the amount of CO2 produced in two minutes. 6. Repeat each reaction three times to get an average of carbon dioxide produced. To work out the percentage of glucose solution, I divided the mass of glucose added by 30 as the yeast solution added was 20cm3 and the water 10cm3 hence a total volume of 30cm3. Conical Flask Yeast Solution added (cm3) Volume of water added (cm3) Mass of glucose added (g) Overall Glucose Concentration (M) A 20 0 0 0 (control set-up) B 20 0 2 C 20 0 4 2 D 20 0 6 3 Results To find the average of the carbon dioxide produced, I added the 3 repeats and divided it by 3. To work out rate of reaction I divided average CO2 by the time taken in seconds (120). Conical Flask Carbon Dioxide Produced (cm3) Rate of Reaction/ cm3 s-1 Repeat 1 Repeat 2 Repeat 3 Average Average CO2/Time (Secs) A 7 7 8 7.33 7.33/120= 0.06 B 7 8 7 7.33 7.33/120= 0.14 C 6 20 9 8.33 8.33/120=
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
A-Level Biology Revision Notes
PBL 1 Out firm . Define terms: Rouleaux: A cylindrical structure in the blood formed from several red blood cells piled one upon the other and adhering by their rims. Transient Ischaemic Attack: (TIA) The result of temporary disruption of the circulation to part of the brain due to embolism, thrombosis to brain arteries, or spasm of the vessel walls. The symptoms maybe similar to those of a stroke but patients recover within 24 hours. ESR: (Erythrocyte Sedimentation Rate) The rate at which red blood cells (erythrocytes) settle out of suspension in blood plasma, measured under standardized conditions. The ESR increases if the level of certain proteins in the plasma rises, as in rheumatic disease, chronic infections, and malignant disease, and thus provides a simple but valuable screening test for these conditions. Serum Ferritin: An iron-protein complex that is one of the forms in which iron is stored in the tissues. Reticulocytes: An immature red blood cell (erythrocyte). Reticulocytes maybe detected and counted by staining living red cells with certain dyes that result in the formation of a blue precipitate (reticulum) within the reticulocytes. They normally comprise about 1% of the total red cells and are increased (reticulocytosis) whenever the rate of red cell production increases. Total Iron Binding Capacity: A test that measures indirectly the transferrin
Blood Brothers
"Blood Brothers" is a musical by Willy Russell. It is one of the longest-running works of musical theatre in history. The musical has a contemporary nature vs. nurture plot, revolving around fraternal twins who were separated at birth. The twins' different backgrounds take them to opposite ends of the social spectrum, one becoming an Oxbridge-graduated councilor and the other unemployed and imprisoned. Both fall in love with the same girl, with tragic consequences. The play writer, Willy Russell was born a scout in Liverpool. He grew up in a working class family. After leaving school with one O-level in English, he first became a ladies hairdresser and ran his own salon. Russell then undertook a variety of jobs, also writing songs which were performed in local folk clubs. He also contributed songs and sketches to local radio programmes. At 20 years old, he returned to college and became a teacher in the Toxteth area of Liverpool. Around this time he met his wife, Annie, and became interested in writing drama. As Willly Russell was brought up in the working class its not surprising that he left school with just one O - level. Also it's not surprising that he wrote a play write showing the digression of growing up in the working class. "Class" is central to the story as it is a theme that exists throughout the play. Willy Russell has shown the class affects people's lives by
Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis
COURSEWORK INVESTIGATION Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis Tahir Aziz CONTENTS > Plan > Outline method > Key variables > Risk assessment > Preliminary results > Method > Results of control experiments > Results > Conclusions > Main trends and patterns > Explanation of results > Experimental limitations Affect Of Varying Salt Concentration on Red Blood Cell Haemolysis Abstract The average adult has about five litres of blood living inside of their body, coursing through their vessels, delivering essential elements, and removing harmful wastes. Without blood, the human body would stop working. Blood is the fluid of life, transporting oxygen from the lungs to body tissue and carbon dioxide from body tissue to the lungs. Blood is the fluid of growth, transporting nourishment from digestion and hormones from glands throughout the body. Blood is the fluid of health, transporting disease fighting substances to the tissue and waste to the kidneys. Because it contains living cells, blood is alive. Red blood cells and white blood cells are responsible for nourishing and cleansing the body. Since the cells are alive, they too need nourishment. Vitamins and Minerals keep the blood healthy. The blood cells have a definite life cycle, just as all living organisms do. Approximately 55 percent of blood is plasma, a straw-collared clear
Aim: To test for reducing sugars using glucose, sucrose and lactose to see which one can be reduced.
Reducing and non-reducing sugars and the Test Reducing Sugars (Benedict's test). All monosaccharide and most disaccharides (except sucrose) will reduce copper (II) sulphate, producing a precipitate of copper (I) oxide on heating, so they are called reducing sugars. Benedict's reagent is an aqueous solution of copper (II) sulphate, sodium carbonate and sodium citrate. To approximately 2 cm³ of test solution add an equal quantity of Benedict's reagent. Shake, and heat for a few minutes at 95°C in a water bath. A precipitate indicates reducing sugar. The colour and density of the precipitate gives an indication of the amount of reducing sugar present, so this test is semi-quantitative. The original pale blue colour means no reducing sugar, a green precipitate means relatively little sugar; a brown or red precipitate means progressively more sugar is present. Non-reducing Sugars (Benedict's test). Sucrose is called a non-reducing sugar because it does not reduce copper sulphate, so there is no direct test for sucrose. However, if it is first hydrolysed (broken down) to its constituent monosaccharides (glucose and fructose), it will then give a positive Benedict's test. So sucrose is the only sugar that will give a negative Benedict's test before hydrolysis and a positive test afterwards. First test a sample for reducing sugars, to see if there are any present before
Investigation into the density of mock blood.
. Assessed practical: A2 Practical. Investigation into the density of mock blood. Aim: to find any difference in blood density in the mock blood samples belonging to: * a healthy male living at sea level (a); * the same male after he has undergone 6 months of regular aerobic exercise (b); * the same male who has spent 3 months undergoing aerobic training at altitude (c). Background knowledge: Blood is composed of watery plasma in which a variety of cells are present. The majority of cells present are red blood cells, or erythrocytes. These are red biconcave discs about 7?m in diameter. They have no nucleus, no mitochondria and no endoplasmic reticulum, this is to maximise the amount of oxygen which can be carried by each blood cell. The red colour is caused by the globular protein haemoglobin. The main function of haemoglobin is to transport oxygen from the lungs to respiring tissue. Oxygen is transported around the body in the red blood cells in combination with haemoglobin. Each haemoglobin molecule is made up of four polypeptides each containing one haem group, each of which can combine with one oxygen molecule. Therefore each haemoglobin molecule can combine with four oxygen molecules. This can be represented by the following equation: Hb + 4O2 HbO8 Haemoglobin oxygen
