Rate of Respiration

Aim The purpose of this investigation is to discover whether different respiratory substrates will affect the rate of respiration of yeast. I will investigate this by measuring the amount of C02 evolved during anaerobic respiration. As C02 is a waste product produced during respiration, measuring the volume of c02 produced will allow me to evaluate which of the sugars are best metabolized during respiration (of yeast). Background information Yeast Yeasts are a form of eukaryotic microorganisms that are used heavily in industry to be used for fermentation of alcohols and baking. Yeast digest the sugars using extracellular enzymes to break down the compounds, thus yeast are known as saprophytes, which the products will be transported into the cell of the yeast by facilitated diffusion to be respired. The yeast synthesises the enzymes required that will be specific to the substrate that they will be digesting. For example, domestic yeast is sold in as a sucrose solution, and the cell membrane of the yeast contains a high concentration of sucrose enzymes, thus the yeast adapts its digestive enzymes to its environments to digest specific sugars. Yeast can respire both through aerobic and anaerobic respiration, depending on the availability of oxygen present within the surrounding area. If oxygen is not present then fermentation occurs which converts sugars i.e. glucose into

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  • Level: AS and A Level
  • Subject: Science
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This experiment aims to investigate the effects of 4 different types of fish food on the growth of guppy fry.

**** **** Student Name Candidate Number Report Title: Word Count A2 BIOLOGY RESEARCH INVESTIGATION RICHMOND UPON THAMES COLLEGE Centre Number: 14619 **** **** ********** Fish Food Experiment 8,765 **** **** Fish Food Experiment Aim This experiment aims to investigate the effects of 4 different types of fish food on the growth of guppy fry. The fish foods to be tested are TetraPrim a Tropical, Aquarian Tropical Flakes, Freeze-Dried Brine Shrimp and Natural foods such as mosquito larvae, algae and daphnia in which guppy fry feed on in the wild. Introduction Guppies (Poecelia reticulata) are renowned for the resilience in conditions much different from their normal habitat. Their survival rate in captivity is far greater than that of the wild, and they are extremely prolific breeders in almost all conditions . Unlike many other species of freshwater fish like Goldfish and Cichlids, guppies don t require any special conditions to breed and have been bred easily through natural means in bare glass tanks. Their hardiness also extends into the water conditions they can survive in. Guppies prefer harder and slightly alkaline conditions, however they have been successfully bred in acidic conditions and even in saline solutions exceeding that of sea-water when acclimated slowly. While it may not be immediately apparent, this experiment has a very important real world

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  • Level: AS and A Level
  • Subject: Science
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Biology coursework planning - the effect of lead chloride on the growth of cress seeds

Biology coursework planning - the effect of lead chloride on the growth of cress seeds Aim: To investigate the effect of different concentrations of a heavy metal chloride, namely lead chloride, on the growth of cress seeds. Introduction: Heavy metals compounds, such as lead chloride are able to dissolve in rain and enter the soils surrounding plants. Some sources of such compounds are exhaust fumes from vehicles, additives in gasoline and paints, fertilisers and mining. Lead chloride is able to accumulate in the soil at sufficient concentrations and is easily absorbed by plants. For plants, lead is a toxin and when present in significant amounts, can cause severe decreases in their growth as well as death. The toxicity of heavy metals is seen as the irregularities in the normal functioning of the plant rather than direct toxicity to plant cells. Symptoms include stunted growth and the yellowing of plants (called chlorosis). Heavy metals collect in different organs of a plant and produce variable effects. Lead disrupts the plant's plasma membrane structure as well as permeability (proteins in the membrane), osmotic balance (the intake of water and ions) and indirectly, plant metabolism (the availability of nutrients for chemical reactions.) These factors are discussed below in further detail. The root cells of a plant carry proteins called chelates in their cell

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Design an experiment to investigate the effect of temperature on the movement of a pigment through a membrane

Design an experiment to investigate the effect of temperature on the movement of a pigment through a membrane Hypothesis The tonoplast is the membrane that separates the vacuole from the rest of the cell. The membrane is selectively permeable and a phospholipid bilayer. The membrane is made up of phospholipids, which have a phosphate group and two fatty acid tails. The phosphate group is polar and hydrophilic, whereas the fatty acid tails are non-polar and hydrophobic. The fatty acid tails therefore try to get as far away as they can from the watery fluid in the vacuole and the watery cytoplasm, so the fatty acid tails point inwards and the phosphate heads point outwards. Also in the bilayer there are proteins, which can be intrinsic or extrinsic. Intrinsic proteins are proteins that span the full width of the membrane, whereas extrinsic proteins only go a small way into the membrane. The proteins provide structural support, act as carriers for water-soluble substances, can act as enzymes, form ion channels and they can act as receptors for hormones. Carbohydrate chains can join to the extrinsic proteins forming glycoproteins. These act as recognition sites. Carbohydrate chains can also join to the phospholipids forming glycolipids, this act as recognition sites and helps the stability of the membrane. Also there is cholesterol in the membrane this prevents leakage of water

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  • Level: AS and A Level
  • Subject: Science
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The comparison of antibacterial properties of herbal products and standard antibiotics

The comparison of antibacterial properties of herbal products and standard antibiotics Introduction: This is As biology coursework, studying the area of microbiology the main investigation contains the comparison of antibacterial properties of herbal products and standard antibiotics. Aim: The aim is to investigate the effect of herbal products against standard antibiotics on bacteria growth. To examine the extent to which the herbal products (tea tree oil and peppermint oil) and the standard antibiotics (penicillin and streptomycin), reduce bacteria growth of E.coli and M.luteus. This will be discovered by measuring the growth of bacteria on the agar plates and comparing the results. Background information: The proposed aim surrounds the study of bacteria growth and various other products, which can have an affect on the growth rate; it is therefore necessary to look deeper into the topic criteria to get a wider understanding and to help design an appropriate hypothesis. From self-knowledge antibiotics are chemicals produced by microorganisms, which are designed to inhibit and destroy specific pathogens when used at low temperatures. Antibiotics release chemicals, which inhibit bacterial growth and work on a specific action site. The first founded antibiotic was penicillin discovered accidentally by Alexander Fleming in 1928 from a mold culture. It can be

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"An investigation into the Respiration of Carbohydrate Substrates by Yeast."

AS Biology Coursework 2004. Lucy Nuttney "An investigation into the Respiration of Carbohydrate Substrates by Yeast." Abstract. The investigation considered the reactivity of respiration of three different carbohydrate substrates; glucose, sucrose and starch, by two different sub-species of saccharomyces cerevisiae yeast. The rate of reaction was measured by collecting volumes of gas in a displacement reaction at standardised conditions e.g. time, temperature, pressure, volume of yeast/ sugar. Results showed that glucose produced the most carbon dioxide, followed by sucrose then starch, the biggest difference being between sucrose and starch. Baker's yeast had a slightly higher average than brewer's yeast but it was not considered to be a significant difference and therefore could have been due to chance. It was concluded that both yeasts respire glucose and sucrose at insignificantly different rates but the difference between starch is much larger and therefore much more significant. Pilot Experiment. Before we could test which carbohydrate and type of yeast produced more carbon dioxide, we had to standardise the other variables of this experiment; temperature and concentration. Therefore, in order to find the optimum conditions we carried out a pilot experiment. In this experiment we used a range of temperatures from 10° to 60°C and

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Human Reproductive System

The Human Reproductive System Structures of the male reproductive system Bulb of penis The bulb of penis is the expanded posterior part of the corpus spongiosum of the penis. It lies in the interval between the crura of the penis. It contains slightly dilated and angulated portion of the urethra. Bulbourethral (Cowper's) gland The bulbourethral gland is pea-sized structures located on the sides of the urethra below the prostate gland. It produces a clear, slippery fluid that empties directly into the urethra. These fluids lubricate the urethra and neutralises any acidity that may be present due to residual drops of urine in the urethra. Corona The corona is a rounded projecting border that forms the circumference of the base of the glans. It is located behind the penis and overhangs a deep retroglancular sulcus Corpora cavernosum penis The corpus cavernosum penis is one of the pair of sponge-like regions of erectile tissue in the penis. It contains irregular spaces which are filled with blood during erection. These spaces are lined by endothelium and separated by connective tissue septa. Corpus spongiosum penis The corpus spongiosum penis is the median column of erectile tissue located between and ventral to the two corpora cavernosa penis. Posteriorly It expands into the bulb of penis and terminates as enlarged glans penis anteriorly. Ductus (vas) deferens The

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Investigation on Osmosis using a potato.

Investigation on Osmosis using a potato. Aim The aim of the experiment is to see osmosis in potato's by changing the variable which is going to be concentration, we are going to see at what concentrations the potato gains mass, and at which concentrations the potato loses mass, and at which individual concentration does the potato not gain or loss mass at all, this will be the equilibrium. Scientific Theory Osmosis is the movement of water molecules across a partially permeable membrane from its region of high water concentration to a region of low water concentration. In this test I have a range of choices in which I will have to choose from to prove a scientific fact. I have the options of testing with the potato to see how temperature will affect its rate of osmosis/plamolysis, and how the potato will be affected by osmosis when increasing/decreasing its surface area. But there is another choice and it is that I can change the concentration of solution which the potato is put into and this will very much affect the rate of osmosis/plasmolysis on the potato. I have decided to make the variable the difference in concentration because it will give a wider range of results helping me to analyse it better. Baring this in mind I also have to consider that these are my non variables: * Surface area * Solution volume * Duration of experiment * Temperature * Solution

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  • Level: AS and A Level
  • Subject: Science
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Osmosis. Aim: To find the molarity of potato tubers cell sap. BIOLOGICAL KNOWLEDGE

TABLE OF CONTENTS Biological Knowledge ... 3 Explanation ... 3 Types of solutions and its effects on plant cell ... 4 Factors affecting rates of osmosis ... 6 Outline Method ... 9 Apparatus ... 9 Materials ... 9 Risk Assessments ... 9 Precautions ... 9 Apparatus Diagrams ... 10 Factors to be controlled ... 11 Method ... 11 Calculations to be used ... 12 Predicted Results ... 12 Prior Test ... 13 Obtaining Evidence ... 16 Apparatus ... 16 Materials ... 16 Risk Assessments ... 16 Precautions ... 16 Method ... 17 Results obtained for Mass ... 18 Results obtained for Length ... 19 Analysis ... 21 Trends in the Bar charts ... 25 Scientific Explanation ... 25 Determination of molarity ... 28 How far I have reached my predicted results ... 30 Evaluation ... 32 Errors ... 32 Accuracy and reliability of my results ... 32 Extension work ... 33 Bibliography ... 33 INTRODUCTION Biology Coursework Aim: To find the molarity of potato tuber's cell sap. BIOLOGICAL KNOWLEDGE Osmosis is the diffusion of fluid through a semi-permeable membrane from a solution with a low solute concentration to a solution with a higher solute

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Alleopathy

Will the allelochemicals produced by grass seeds inhibit the growth of wheat seeds? Abstract: This investigation was designed to see what effect the allelopathic chemicals of grass seeds had on wheat seeds. This was done by placing 20 grass seeds on a petri dish, with two sheets of filter paper inside, which was watered with 5ml of distilled water every three days for a week. After one week of growth the seeds were removed, then another 20 wheat seeds were placed on the second piece of filter paper as the first was discarded, and the same process was repeated. This was repeated in five more petri dishes. At the same time 60 wheat seeds were grown as a control, so the results could be compared. A clear inhibition of root and shoot growth could be seen in the experimental group compared to the control group. Many wheat seeds in the test group did not even germinate. In conclusion the allelochemicals produced by grass seeds have an inhibitory effect on the wheat seeds. Aim: The aim of this investigation is to see whether the allelochemicals produced by grass at germination inhibit the growth of wheat seeds. Background: What is allelopathy? Allelopathy is any direct or indirect harmful effect by one plant (including micro-organisms) on another through the production of chemical compounds, known as allelochemicals, that escape into the environment.1 Chemicals that

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  • Level: AS and A Level
  • Subject: Science
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