Using examples, describe the structure of lipids and their role in organisms
Using examples, describe the structure of lipids and their role in organisms Lipids are a varied group of organic compounds that can be classified into fats, phospholipids, waxes and sterols.1 As they are non-polar molecules, with the exception of phospholipids, they are insoluble in water but soluble in organic solvents such as alcohol and ether. Lipids contain carbon, hydrogen, oxygen and sometimes phosphorus and nitrogen. They are intermediate-sized molecules that do not achieve the giants sizes of polysaccharides, proteins and nucleic acids.2 The triglycerides, which act mainly as energy stores in animals and plants, are a large important group of lipids. They consist of one molecule of glycerol and three fatty acids, as shown below. Fig.1 Triglyceride3 The glycerol molecule is common to all triglycerides and so the properties of different triglycerides depend on the nature of the fatty acids. Fatty aids vary in the length of their chain and in the degree of saturation they show. Many animals store energy in the form of triglycerides: gram for gram, they yield more than twice as much energy as proteins or carbohydrates. In plants, they are mainly found in the seeds. Triglycerides are highly reduced compounds and contain many C-H bonds which can yield energy during respiration. There is a far greater ratio of hydrogen to oxygen in a lipid such as C14H26O2 than
Supporting the growth of Yeast Cultures
Supporting the Growth of Yeast Cultures with Different Carbon Sources Aim: To investigate the difference in growth rates between yeast cultures that have been grown in different carbon sources. Introduction: An investigation in being carried out to see whether the support of different carbon sources have an adverse effect on the growth rate of yeast cultures. Carbon sources are used to provide carbon as a macronutrient to micro-organisms to enable them to grow and reproduce rapidly. Carbon is often provided in the form of organic substances including glucose, organic acids, fatty acids or amino acids, for example photoautotrophic microorganisms such as Chlorella use carbon dioxide as their carbon source, which in affect supports their growth. Yeast, a single celled living microorganism is a type of fungi that also needs nutrition to enable it to reproduce efficiently. Therefore, the purpose of this experiment is to investigate which carbon source enhances the growth of yeast over a set period of time. Materials/Apparatus * Conical flasks were used to mix the yeast, water and other compounds to produce a yeast culture whilst avoiding any spillages. * Measuring cylinders were used to measure the correct amounts of distilled water for the yeast culture. * An incubator was used to place the yeast culture in and increase the pressure to kill any unwanted micro-organisms. *
Yeast Coursework
Biology Coursework: Respiration in Yeast Planning Aim The goal of this experiment is to discover how varying the temperature, of a solution of yeast and sucrose, will affect the amount of carbon dioxide produced during a set time period. After I have completed this experiment and obtained enough data, I will analyse and discuss it, and then I will evaluate it. For this experiment, my independent variable will be the temperature, which I will change by adding warm water to it. My dependent variable will be the amount of carbon dioxide given off. My controlled variable will be the amount of sucrose and yeast there is in the solution, and also the time the experiment will be running for, as these are the only factors that can be varied to produce different amounts of CO2. Background Knowledge This experiment involves enzymes, which are biological catalysts. All the chemical reactions in a living organism are collectively known as the metabolism. Anabolic reactions normally need an input of energy, to build up large molecules from smaller ones. Catabolic reactions often release energy when breaking down large molecules into smaller ones. An example of anabolism is the condensation of glucose molecules, which happens in liver cells and skeletal muscle. An example of catabolism is the breakdown of glucose into carbon dioxide and water through respiration. Again, this also
Aluminium is the third most common element on Earth after oxygen and silicon.
Introduction Aluminium is the third most common element on Earth after oxygen and silicon. The aluminium industry had a Gross Domestic Product of $3.1 billion in1997/98, ranking the aluminium industry amongst Australia's leading manufacturers and employs over 16000 people directly. The total value of export earnings was about $6.3 billion in 1998/99, second only to coal as an export industry for Australia. These facts underline the fact that the aluminium industry is a major asset to Australia and is world competitive. Aluminium is important to us currently and is used from everything from soft drink cans to car bodies to window frames. Aluminium is lightweight, strong, long-lasting, highly corrosion resistant as a protective oxide coating is naturally generated, is an excellent heat and electricity conductor, has good reflective properties, is very ductile, completely impermeable and odourless and totally recyclable. Despite this, less than 200 tonnes in 1885 were produced compared to approximately 22 million tonnes in 1998 - plus some 5 million tonnes of recycled Aluminium. This is because aluminium is so highly oxidized that it can be only refined using huge amounts of electricity and electricity did not become readily available until this century. Thus, it is known as the metal of the 20th century. There are three process involved in the manufacture of Aluminium: Bauxite
chemistry of renewable resources
Introduction Everything we need - our resources have come from our planet, whether it is food, water, metals or fuels. It is known that if we use up any one of the earths resources then we will be without it forever. In this report I will look at some general principles of how non-renewable and renewable resources are used and the effect this can have on our environment. The resources that are most important to us are coal, metals, oil, gas, petrol and limestone. Without these we will be helpless. Also, these can only be replaced by nature after many million years. We call these non-renewable resources. Many industries rely on these as source of raw materials and will face problems unless new sources or new manufacturing techniques are found. We cannot find any techniques because most of the earths materials are so mixed up, that we can't sort them out and make them useful. On the other hand renewable resources renew themselves more quickly such as plants grown for food, and fuel. But these can be used up too fast if we do not use them carefully. These resources are in continuous supply, for instance wind and solar energy. Scientists are working very hard on developing new ways to use these renewable resources. But first industry needs to make more products that use the safe environmentally energy like solar powered vehicles. In the future they could also include the use of
Eyesight coursework
Eyesight project Describe causes and symptoms of long and short sight and how they are corrected Introduction These extremely common problems are the result of small variations in the shape of the eyeball that affect the ability of the lens to focus light on the back of the eye. This focuses by varying the thickness of the lens, using tiny muscles around its perimeter. If the eyeball is either too short or too long in relation to the maximum power of the lens then the light can never be focused and vision is blurred. Short sight, myopia, results from having an eyeball too long for the focusing power of the lens. This means that light gets focused in front of the retina unless the object is brought extremely close to the eye. The opposite situation is the case in long sight, where the eyeball is short in relation to the power of the lens. In this case the point of focus is further behind the retina. The size and shape of the eyeball is something that we are all born with; the power of the lens to contract and expand and, therefore, to vary its focus changes over time. This is the reason why as you get older it is increasingly difficult to focus on objects close by whereas you can see with relative comfort things which are a long way away. Thus, over a lifetime, short sight gradually corrects itself and long sight gradually becomes worse. Symptoms The symptoms are simply
Describe the concept of homeostasis and the homeostatic mechanisms that regulate heart rate, breathing rate, body temperature and blood glucose levels.
Saira Iram Shaukat Unit 5- Senzenni Assignment 4 Homeostasis-P5 P5) Describe the concept of homeostasis and the homeostatic mechanisms that regulate heart rate, breathing rate, body temperature and blood glucose levels. Definition of Homeostasis The actual word homeostasis means "steady state". Homeostasis describes how the body regulates its process to keep its internal conditions as stable as possible. Homeostasis is necessary because human cells are efficient but very demanding. The phrase "steady state" is a bit confusing; the conditions inside our bodies are not constant but are kept within a narrow range. Some factors such as core temperature and blood pH change slightly while others such as blood glucose vary considerably throughout a normal day without producing any harmful effects. A very brief description of homeostasis is that it is the maintenance of a constant internal environment in response to a change in external environment. Internal environment The conditions that prevail within the body of an organism, particularly with respect to the composition of the tissue fluid. To function properly they need to be bathed in tissue fluid that can provide the optimum conditions. Nutrients and oxygen must be delivered and waste needs to be removed. To maintain the internal environment there are 3 things that need to be done: * Organisms keep conditions in
Mitochondria & Chloroplast
Mitochondrion Chloroplast Similarity Main power source of the organism Double membrane, and intermembrane space. Contain DNA and RNA, which are involved with the synthesis of the membrane and enzyme proteins, when the organelles replicate during cell division. Contain 70s ribosomes. Contain similar enzymes and coenzymes Both are involved in ATP production via a proton gradient (across the thylakoid membrane of chloroplast, across the cristae for mitochondria) Have ATP-synthatases appearing as stalked particles (on the thylakoid membrane of chloroplast, on the cristae of mitochondria) Have electron transport chains (on the thylakoid membrane of chloroplast, on the cristae of mitochondria) Self-replicate. Differences found in both plants and animals. found in plants only Help in respiration help in photosynthesis. No pigment contains thylakoid membranes and pigment molecules Matrix Stroma Releases energy from sugar Requires energy (light) to make sugar (glucose) Complex substances (sugar) are broken down into simpler ones. Complex substances (sugar) are formed from simpler ones. Krebs cycle Calvin cycle Compare chloroplast and mitochondria Chloroplast can only be found in plants, while mitochondria can be found in not only plants but also in animals. They have some similarities like: they both have double membrane and intermembrane space; Contain
Investigating the effect of pollution on freshwater invertebrates, using Mayfly Nymph as an indicator.
Investigating the effect of pollution on freshwater invertebrates, using Mayfly Nymph as an indicator. Background Information Pollution can be defined as "adding to the environment a potentially hazardous substance or source of energy faster than the environment can accommodate it." Freshwater pollution Organic waste, such as sewage is often dumped into rivers, as it is the easiest way to get rid of it. If the discharge of organic waste is small compared to the amount of water in the river, then it is broken down to simple in organic substances by bacteria and fungi, a process known as self-purification. If however the discharge becomes too much, bacteria thrive and begin to use up oxygen from the river, this causes a biological oxygen demand. (B.O.D) Eutrophication Eutrophication means nutrient enrichment. The main factor that causes eutrophication is the heavy use of nitrogen fertilisers and the increase in discharge of phosphates from sewage works. Nitrates and phosphates are the nutrients that are usually limiting primary productivity in aquatic ecosystems. Therefore an increase in these nutrients favours an increase in rapidly growing competitive plankton species. Consumer organisms cannot increase in number as quickly in response to environmental change, this means that not all the increased primary production is eaten by the consumer organisms. Death of the
the effect of bile concentration on the activity of the enzyme lipase during the break down of milk
Aim To investigate the effect of the concentration of bile salts on the activity of lipase on the breakdown of milk. Introduction From prior AS knowledge involving biological molecule I know that lipids are broken down into fatty acids and glycerol by the action of the enzyme lipase. Subsequently using this information in the experiment we will be measuring the fall in pH using a pH probe to find the rate of reaction of the experiment. This is because if lipase is breaking down the lipids then the pH should fall and become more acidic as fatty acids which are acidic are being produced. By keeping the variables the same except for the concentration of bile salts we can be able to see what affect, if any the bile salts have on the activity of the enzyme lipase on the breakdown of lipids, with our source of lipids being milk. In addition to this by using accurate apparatus and by keeping the conditions the experiment is done in the same I will be able to make my results both precise and accurate. Background Enzymes An enzyme is a biological catalyst that speeds up the rate of a chemical reaction by lowering the activation energy needed by the reactants to react, thus allowing the reaction to precede much faster by a factor of millions as seen in the graph below. Like all catalysts, enzymes remain unaltered by the completed reaction and can therefore continue to function,
