Essays Tagged: "molecules"

Biology AT1 on the affect of hydogen peroxide on the liver

e enzyme molecule. This depression is called the active site. The reaction then takes place and the molecules of product leave the active site, freeing it for another substrate molecule. ...

(2 pages) 51 0 4.5 Jan/1996

Subjects: Science Essays > Biology > Human Biology

Virtual Reality

cientists at the University of North Carolina have developed a system that simulated the bonding of molecules. However, instead of using complicated formulas to determine bonding energy or stick drawi ...

(3 pages) 103 0 4.2 Nov/1996

Subjects: Science Essays > Technology

Immunodeficiency viruses researched by Jacek Skowronski

disrupts the T cell receptor (TCR). It changes the expression of major histocompatibility complex I molecules, known as MHC I, a condition of compatibility between tissues of foreign objects and the t ... or simian. The interference is characterized as AIDS.To study the function of Nef, he uses genetic molecules to identify the cells involved in affecting the T lymphocyte. He also studies SIV-infected ...

(1 pages) 39 0 4.1 Mar/2002

Subjects: Humanities Essays > Health & Medicine

The Immune System

The immune system is a group of cells, molecules, and tissues that help defend thebody against diseases and other harmful invaders. The imm ...

(3 pages) 157 1 3.4 Oct/1996

Subjects: Humanities Essays > Health & Medicine

research paper on marijuana

Doctors are not sure of how the hippocampus uses the endocannabinoids, but they suspect that these molecules strengthen the connections between nerve cells, thus, strengthening memory abilities.5)Whe ... nnabinol. Because the body does not always produce endogenous cannabinoids and the feeling of these molecules are pleasing, some people look to get the same feeling through marijuana.Although addictio ...

(5 pages) 306 1 3.1 May/2002

Subjects: Humanities Essays > Health & Medicine > Drugs

VR, What it is and How it Works

Imagine being able to point into the sky and fly. Orperhaps walk through space and connect molecules together.These are some of the dreams that have come with theinvention of virtual reality. ...

(1 pages) 52 0 4.0 Oct/1996

Subjects: Science Essays > Computer Science

DOPAMINE NB:sorry for the previous esssay it was sent by mistake i didn't mean to send two same essays

just concentrate on the chemistry of them. The moment you take one of them, trillions of poisonous molecules enter to your brain, once there they let loose of a kind of 'neurological chain reaction r ... igh whose intensity was directly related to how only cocaine tied up available binding sites on the molecules that transport dopamine around the brain. She and her colleagues found, that to producers ...

(13 pages) 178 1 4.9 Jun/2002

Subjects: Social Science Essays


tube, a wave compression passes along the tube.When it reaches the closed end, it is reflected. The molecules of reflected airmeet the molecules of oncoming air forming a node at the closed end. Whent ... tube, a wave compression passes along the tube.When it reaches the closed end, it is reflected. The molecules of reflected airmeet the molecules of oncoming air forming a node at the closed end. Whent ...

(4 pages) 40 0 2.3 Jan/1996

Subjects: Science Essays > Physics


A simple essay on computer viruses Could have added more examplesViruses: Complex Molecules or Simple Life Forms?Viruses have been defined as 'entities whose genomes are elementsof n ... unableto grow. Because of all these factors, it is debatable whether virusesare the most complex of molecules or the simplest life forms. While thedefinition of living organisms must be adapted, the m ...

(3 pages) 85 0 4.6 Apr/1996

Subjects: Science Essays > Biology

"Gas Law Variables" It describes volume, pressure, and amount of gas.

hin the limits of any experiment, the walls remain fixed and the volume stays constant.Pressure:The molecules of gas hitting the walls of the container create gas pressure. This concept is very import ...

(1 pages) 44 0 3.5 Dec/2002

Subjects: Science Essays > Physics


rase chain reaction (PCR), can be used to amplify rare specific DNA sequences into many billions of molecules when the ends of the sequence are known. The method of amplifying rare sequences from a mi ... ents. The other type, called DNA ligases, can insert DNA restriction fragments into replicating DNA molecules producing recombinant DNA. The recombinant DNA molecules then can be introduced into appro ...

(22 pages) 278 2 3.0 Dec/2002

Subjects: Science Essays > Biotechnology

"Experiment to investigate the effect of osmosis in potatoes" A GCSE experiment looking at the effects of the concentration of sucrose solution on osmosis in potato tubers.

ome things to pass through, but prevent others. A cell membrane is semi permeable. They allow small molecules like oxygen, water, amino acids etc. to pass through but will not allow larger molecules l ... rgone plasmolysis. This very rarely, if ever happens in nature.As osmosis is the diffusion of water molecules and as diffusion is the random movement of particles from areas of high concentration to l ...

(11 pages) 191 1 4.7 Jan/2003

Subjects: Science Essays > Biology

Catalase investigation

shape. They are therefore specific in the reactions that they catalyse. One enzyme will react with molecules of one substrate. The site of the reaction occurs in an area on the surface of the protein ... curs in an area on the surface of the protein called the active site. Since the active site for all molecules of one enzyme will be made up of the same arrangement of amino acids, it has a highly spec ...

(6 pages) 119 0 4.3 Mar/2003

Subjects: Science Essays > Biology

The bio-psychological approaches to understanding mental events and behaviour result in more conclusive findings than using a social approach and/or examining environmental factors. Discuss.

haracteristics can be attributed to the make up of the individuals nerve cells and their associated molecules. Crick therefore believes that all mental events and behaviour can be explained as simply ...

(9 pages) 221 2 3.9 Apr/2003

Subjects: Social Science Essays > Psychology

quick assignment on the digestive system and how the different types of foods eg protein,carbohydrates ect are broken down in the body.

igestive System AssignmentIntroduction: Digestion is the process of breaking down food into smaller molecules that can be absorbed into the bloodstream.The digestive systems most important function is ... epair·Nerve transmission·Maintain body temperaturePhysical digestion is when the food molecules are broken down into smaller pieces by the digestive systems organs to enable it to be pro ...

(4 pages) 97 0 4.8 Apr/2003

Subjects: Humanities Essays > Health & Medicine > Health & Fitness

Enzyme-controlled reaction, factors that affect the chemical structure and properties of the enzyme.

ture :As the temperature is increased the kinetic theory is applied. More energy is present and the molecules move fast. This increases the chance of collision between the enzymes and substrate and so ... s totally specific and only catalases a single reaction.iii)In the prosthetic group are non-protein molecules. They are covalently (strongly) bonded to the enzyme and must be there for the enzyme to f ...

(3 pages) 95 0 3.0 Apr/2003

Subjects: Science Essays > Biology

Red Blood Cells.

and carbon dioxide around. While I am floating around the blood, the iron magnetically attracts the molecules, the molecules attach to me, and then I transport them all around the body. On average, me ... yellow-colored. Once I pass through the body tissue, the hemoglobin releases all of the oxygen and molecules out to all of the cells. The hemoglobin that is left over then bonds with carbon dioxide, ...

(2 pages) 44 1 4.0 Jun/2003

Subjects: Science Essays > Biology > Human Biology

The effect that temperature has on enzyme activity.

ogical catalyst to break down starch, which cannot pass through the gut wall due to the size of the molecules, into smaller ones. Amylase is a carbohydrase, which converts starch to simple sugars in t ... ace in our body, inside and outside cells. This is the right temperature for the random movement of molecules, so that they collide as often as possible, without being destroyed. Without enzymes the r ...

(6 pages) 189 0 1.5 Jul/2003

Subjects: Science Essays > Biology

Ozone Layer Depletion.

r occurred over a billion years ago, when blue-green algae began using energy from the Sun to split molecules of H2O and CO2 combined them into organic compounds and molecular oxygen (O2). Everyone kn ... Some of the photo synthetically created oxygen is combined with the organic carbon to recreate CO2 molecules. This remaining oxygen, which has accumulated in the atmosphere, produces a massive ecolog ...

(7 pages) 115 0 3.4 Oct/2003

Subjects: Science Essays

Sickle cell anemia.

d can bind oxygen just as well as the normal hemoglobin, but when the oxygen level is low, the Hb S molecules join to form stiff fibers. These fibers distort the shape of the red blood cells making th ...

(4 pages) 94 1 4.8 Nov/2003

Subjects: Science Essays > Genetics & Genome Projects