the heart

The heart Intro: The heart is a muscular organ and is responsible fore pumping blood around the body, and on average the human heart beats at 72 beats per minute. When looking at the heart (see diagram) it is important to remember that the left and right side are reversed (due to the way we are looking at it). The right side of the heart deals with deoxygenated blood and pumps it into the lungs. The left side of the heart deals with oxygenated blood, and pumps it around the entire body. The lower chambers of the heart is know as the ventricles and is more muscular and stronger than the upper chambers, known as the atria. This is because a large volume of blood is pumped from the ventricles up through the atria and around the body. It is important to maintain a healthy heart, as it reduces the risk of developing high blood pressure and cholesterol levels, as well as developing heart disease. By eating healthy and doing regular exercise we are able to reduce theses factors as well as reducing stress levels too. Main: The heart is a muscular organ that it part of the cardiovascular system. It is located between the lungs, behind the sternum and is approximately the size of a fist. The heart is protected by a membrane called the pericardium which surrounds the heart and secretes a fluid that reduces friction when the heart beats. The atria's job is to receive blood

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The Effect Of Temperature on the Respiration Of Yeast.

The Effect Of Temperature on the Respiration Of Yeast Introduction: - I am going to find out how temperature effects the respitory action of yeast. I am going to do this by using six different temperatures, 25oC, 30oC, 35oC, 40oC, 45oC and 50oC and a solution called TTC which is absorbed by the yeast cells turning them pink when hydrogen is removed from the metabolic pathway by the dehydrogenase enzyme. Background Information: - Yeast: - Yeast is unicellular fungus that buds profusely under favourable conditions. They are classified as sac-fungi (Ascomyctes) even though they are unicellular. Yeast is common in areas where there is sugar because of this they are given the name saccharomyces (Sugar fungi). They grow on the surface of fruits, in the nectar of flowers, in sap excluded from trees, in the soil and in fresh water. Yeasts are used in all sorts of arrears such as alcoholic fermentation (fermentation is the name given only to the anaerobic respiration of yeast) to baking bread. Yeasts are of a great economic importance and are yeast for biochemical research for example in respiration and enzymes. Yeast exists as Diploid or Haploid cells and divides by mitosis and meiosis. Yeasts are not plant or animal because they do not photosynthesise and they do not have any chloroplast. Yeast is a saprophyte. This is an organism, which obtains its nutrients from dead or

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The Effect of Enzyme Concentration On Enzyme Activity

THE EFFECT OF ENZYME CONCENTRATION ON ENZYME ACTIVITY AIM: To investigate the effect of a reduction in enzyme concentration on the rate of reaction, in this case the breakdown of protein by protease enzyme. The protein substrate in this reaction will be trypsin milkprotein (casein). PREDICTION: I believe thath a higher enzyme concentration results in protein trypsin to be broken down faster/ a faster rate of reaction. The protein solution would turn clear quicker when enzymes are more concentrated. The site of the reaction occurs in an area on the surface of the protein (protease) called the active site. At low enzyme concentration there is great competition for the active sites and the rate of reaction is low. As the enzyme concentration increases, there are more active sites and the reaction can proceed at a faster rate. Therefore i believe as the protease concentration is reduced, the rate of reaction, as well as the trypsin mlk protein, is also reduced. FACTORS AFFECTING THE RATE OF REACTION: Temperature - enzmes work best at an optimum temperature. Below this, an increase in temperature provides more kinetic energy to the molecules involved. The numbers of collisions between enzyme and substrate will increase so the rate will too. Above the optimum temperature, the enzymes are denatured. Bonds holding the structure together will be broken and the active

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The Effect Of Temperature On The Permeability Of The Cell Membrane

"The Effect Of Temperature On The Permeability Of The Cell Membrane" Aim: My aim of this experiment is to investigate whether changing the temperature (independent variable) of the water around a disk of a beetroot will affect the permeability of a beetroot, by measuring the release of pigment (dependant variable) into water using a digital colorimeter. The colorimeter will be used to measure the light absorbency of anthocyanin (the pigment found in the cell membrane of the beetroot) this can help us work out how much diffusion takes place at different temperatures such as 0,20,40, 60 and 80 degrees Celsius. Introduction I will be conducting an experiment to find out what effect different temperatures has on the permeability of the Beetroot's cell membrane; the temperatures that I will be testing on the beetroot is 0, 20, 40 and 60 degrees Celsius. Background Knowledge Most people think that Beetroot cells are colored red because they contain a red dye called anthocyanin, But in fact they are colored red caused by two distinct pigments, there is a yellow one known as a betaxanthin and a purple pigment known as betacyanin and are together they are referred to as betalins. In beetroot cells the red anthocyanin pigment occurs in the vacuoles. A membrane called the tonoplast surrounds each vacuole. The cytoplasm and vacuole is surrounded by the plasma membrane. The

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The effect of caffeine on heart rate

Core Practical 1.1 the effect of caffeine on heart rate Aim: The aim of this experiment is to investigate the effect of different concentrations of caffeine on the heart rate of Daphnia (water fleas). Hypothesis: I predict that the concentration of caffeine will affect the heart rate. I believe this will be directly proportional to each other. For example, as concentration of caffeine in the blood increases, the heart rate of the daphnia will also increase. Caffeine is a drug that is classed as a stimulant because it stimulates the body's systems. It increases the activity of the neurotransmitters in your body which speeds up your heart rate, thus blood is pumped faster around the body. Variables: The dependant variable being observed and measured was the number of heart beats per minute of the Daphnia (water flea).The independent variable in this experiment was the concentrations of caffeine 0.5%, 0.6%, 0.7%, 0.8%, 0.9% and 1%. Fair Testing: To make it a fair test: we kept the timing the same for each condition; the environment for the daphnia were kept the same; the type daphnia was kept the same. This made the results valid as caffeine was the only variable that was manipulated in the experiment. Ethics: Since this experiment involves living organisms, ethical issues were raised. Consideration has been taken into account and the following guidelines were used:

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The Biological Importance of Water

The Biological Importance of Water Water is by far one of the most important substances found on earth; it is vital for living organisms to survive and its structure plays a critical role in this. The most important factor in the structure of a water molecule is its polarity. This occurs because the oxygen atom is larger and therefore of a higher electronegativity (3.44) than hydrogen atoms (2.2). The electronegativity or tendency to pull electrons closer towards itself, determines the polarity of an atom or molecule. For example, a water molecule consists of one oxygen atom and two hydrogen atoms. The high electronegativity of the oxygen atom gives it a slight negative charge (shown by δ-) while the relatively low electronegativity and the consequent drawing away of electrons gives the hydrogen atoms a slight positive charge (shown by δ+). This means that each individual water molecule is dipolar, it has two separate and opposite charges within the same molecule. This is important because it allows a weak ‘hydrogen bond’ to be formed between water molecules, making it a generally cohesive substance. We can observe these electrostatic attractions when rainwater is beaded up on a leaf. It has formed droplets of many water molecules ‘stuck’ to each other through hydrogen bonding. If water did not have a dipole, then it would spread out over the leaf in a thin layer

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The Development of Antiseptics.

The Development of Antiseptics The problem of infection in surgery The death rate of those having surgery in the mid 17th century was very high, almost half of all those having leg amputations died. This era of surgery was very unusual as although the development of anaesthetics was a massive step forward, the death rate soared. This was because surgeons began to undertake more complicated surgery and spend longer doing it, this meant there was a much greater risk of infection - especially when the instruments and operating theatres were rarely, if ever, cleaned. Infection was very high risk and not only because of the lack on cleanliness. When arteries were being tied off often nothing more than ordinary string and there was little chance of keeping germs from spreading in these theatres because that was what they were - theatres. Many students every day would come to them and watch and learn about surgery, with so many of them so near the operation they couldn't be a good thing - but no body knew this. Semmelweiss' ideas on cleanliness Ignaz Semmelweiss had noticed that there was an unusually high death rate amongst women after childbirth and realised that mothers whose children were delivered by a mid-wife usually survived unlike those who had there offspring delivered by medical students. Semmelweiss thought that if only the students washed their hands before entering

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MENTAL HEALTH

AO1 Mental health issues The concept of mental health There are a wide range of different terms that people use to describe mental health these are as follows: The World Health Organisation (WHO) have objectives and functions, which are there core commitment to mental health promotion, these are as follows: - " not merely the absence of disease of infirmity" - "attainment by all people of the highest possible level of health" - To foster activities in the field of mental health, especially those affecting the harmony of human relations" The World Health Organisation defines health as: ... A state of complete physical, mental and social well-being and not merely the absence of disease of infirmity Mental health promotion involves actions that support people to adopt and maintain healthy lifestyles, which therefore create a supportive living condition or environment. Mental illnesses are common and universal. There is no general term for mental health and illnesses. According to research, the most prevalent mental health problems were due to alcohol and drug abuse, family violence and abuse, and suicidal behaviour. Many people in the society are not very familiar with mental health problems. Although, research has shown that about 50 years ago, people would class people with mental health problems and would say they had a 'demon' was inside of them and possessed them.

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Specialised Cells

With the aid of annotated diagrams, discuss the relationship between the structure and function in four specialised human cells. By Mark Cannan. Within the human body the cell is the smallest living organism, it is a microscopic package that contains lots of different organelles that are necessary to survive such as mitochondria, nucleus, Golgi body, rough and smooth endoplasmic reticulum, ribosomes, lysosomes, cytoplasm just to name a few. Cells were first discovered by Robert Hooke, an English philosopher in 1665 and from there, a cell theory was formed. Through the improvement and development of microscopic technologies, cells were looked at even closer and separated into two categories, prokaryotic (bacteria) cells and eukaryotic (animal) cells. There are over two hundred different types (in all shapes and sizes) and it is estimated that there are over 50 trillion cells in the human body. Cells reproduce all the time through mitosis to replace damaged or dead cells. http://en.wikipedia.org/wiki/File:Simplified_spermatozoon_diagram.svg (Accessed 30/10/09) The picture above is an illustrated diagram of a spermatozoon cell, otherwise known as a sperm, which is the male reproductive cell. Starting from puberty and leading through to old age, the testes will produce over a thousand sperm cells every second. The sperm goes through a process called spermatogenesis; this is

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Pros and Cons of Genetic Engineering

Pros and Cons of Genetic Engineering Introduction The first step to understanding genetic engineering and embracing its possibilities for society is to obtain a rough knowledge base of its history and method. The basis for altering the evolutionary process is dependant on the understanding of how individuals pass on characteristics to their offspring. Genetics achieved its first foothold on the secrets of nature's evolutionary process when an Austrian monk named Gregor Mendel developed the first "laws of heredity." Using these laws, scientists studied the characteristics of organisms for most of the next one hundred years following Mendel's discovery. These early studies concluded that each organism has two sets of character determinants, or genes. For instance, in regards to eye colour, a child could receive one set of genes from his or her father that were encoded one blue, and the other brown. The same child could also receive two brown genes from his or her mother. The conclusion for this inheritance would be the child has a three in four chance of having brown eyes, and a one in four chance of having blue. Genes are transmitted through chromosomes which reside in the nucleus of every living organism's cells. Each chromosome is made up of fine strands of deoxyribonucleic acid, or DNA. The information carried on the DNA determines the cells function within the organism.

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