• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Adenosine triphosphate (ATP) is a reservoir of potential chemical energy and an energy currency, mediating most energy coupling in cells.

Extracts from this document...

Introduction

Write an essay about ATP. Adenosine triphosphate (ATP) is a reservoir of potential chemical energy and an energy currency, mediating most energy coupling in cells. ATP and its derivatives are involved heavily in metabolism, however they have other functions such as being allosteric inhibitors and effectors, as well in hormonal response( cyclic AMP). ATP was first isolated from mammalian muscle; it has since been shown to occur in all types of cell, at concentrations varying between 0.5 and 2.5 mg/cm3 . ATP plays such an important role in an organism that without its existence, systems would probably fail. Thus its continuous production is necessary in order to main survival. The structure of ATP is linked very closely to its function, specifically its triphosphate tail, which is the chemical equivalent of a loaded spring. Adenosine triphosphate is a nucleotide consisting of an organic base (adenine), a five carbon sugar (ribose) and a chain sequence of three phosphate groups linked together. The adenosine part of the molecule acts like a 'handle"-it has a shape which can be recognized by highly specific enzymes. When only one phosphoryl group is added to the ribose sugar and base adenine, the nucleotide adenosine monophosphate (AMP) is formed; adding a second phosphoyrl group makes adenosine diphosphate (ADP); and adding a third makes ATP. ...read more.

Middle

ATP hydrolysis is favoured i.e. it has a strong tendency to transfer its terminal phosphoryl group in the presence of an appropriate catalyst(ATPase), a reaction associated with the release of 30.5 kj mol-1 of ATP. There are many reasons for this tendency: firstly, the repulsion between the four negative charges in ATP4- is reduced because two negative charges are removed with phosphate; secondly, the H+ ion which is released when ATP is hydrolysed reacts with the OH- ions to form water- this is a highly favoured reaction. Also the charge distribution on ADP +Pi is more stable than that on ATP. ATP is the central molecule in metabolism. ATP is important not just for driving biosynthetic reactions such as nitrogen fixation and bioluminescence; it is also used as a source of energy for virtually all kinds of movements, including small motions of cellular structures, locomotion of single cells and muscle contraction, where ATP hydrolysis changes the position of the myosin 'head" relative to actin, It also supplies energy for the transport of ions and molecules across cell membranes and so it underlies the whole activity of the nervous system. Active transport systems are driven by the phosphorylation of membrane-bound proteins. In urea synthesis, ATP hydrolysis drives the ornithine cycle which removes toxic ammonia. ...read more.

Conclusion

The enzyme catalyzing the hydrolysis of ATP to ADP and Pi occurs in the membrane. The hydrogen ions are able to pass back across the membrane, through a channel in the ATPase. Flow of hydrogen ions through this channel causes reversal of ATP hydrolysis. Thus although an organism at work uses ATP continuously, ATP is a renewable resource that can be regenerated by the addition of phosphate to ADP. This ATP cycle moves at an astonishing pace. For example, a working muscle cell recycles its entire pool of ATP about once each minute. That turnover represents 10 million molecules of ATP consumed and regenerated per second per cell. In conclusion, the production of ATP can never cease, for energy is needed to drive cellular work, be it chemical, mechanical or transport since the immediate source of energy that powers cellular work is ATP. Cellular reactions, without the free energy to kick start, will take place too slowly to sustain life. It is such an important molecule that no other molecule can replace its functions in an organism. Done by : Stephanie Ow Class: 2S03A Group 1 Comments: this is a well written essay which covers the important details about ATP from its structure, function and its other non energy coupling roles. In the actual essay it would be good to include a diagram of ATP and the coupling to illustrate your point but you did give a good written description. Well done. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Energy, Respiration & the Environment section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Energy, Respiration & the Environment essays

  1. Marked by a teacher

    Describe the role of energy in the body and the physiology of three named ...

    3 star(s)

    Energy assists us in everyday life by helping us to exercise, cook and clean. How we get/ make the energy metabolism The human body consumes energy through food. The food is measured in units either kilojoules or calories. Energy is used in the body in three different ways: * Basal

  2. Weed study. Dandelions - descrption and characteristics. Investigation to dandelion distribution.

    I feel that these results are reliable. Soil Depth - As you can see from my results, the soil depth was quite inconsistent. The soil depth was deeper in some areas than in others. This could be due to the effects of trampling. As this lawn is used for recreational activities, it could be that the soil is more compact.

  1. the Effect of Copper Ions on a

    On graph 3b, for the remaining concentrations i.e. 0.015M, 0.020M, 0.025M and 0.030M, there are error bars present, however the difference between the maximum and minimum values are very small i.e. the readings vary smoothly. This thus shows that even for these concentrations of CuSO4 my average graph plotted for the rate of reaction for amylase hydrolysing starch is very reliable.

  2. To investigate how much energy (Kj) is stored in different types of peanuts and ...

    both of them, the results will turn out different because one base would receive heat faster than the other. 7) I must record the temperature every 10 seconds for 90 seconds. 8) The way the temperature is recorded (horizontally, diagonally).

  1. Investigate the effect of bile salt concentration on the digestion of milk by the ...

    The precision is due completely to the skill of the experimenter in being able to repeat all the same steps and is a measure of the consistency of the results. The need for accurate and precise data is in order to draw valid and consistent conclusions form the results.

  2. Testing the Physical and Chemical properties of soils .

    This clay is highly fertile and has a slightly alkaline pH. The upper catchment tributaries and levee banks of the Lockyer creek are well drained and of a loamy texture however other alluvial soils in the region are not as well drained making them heavier.

  1. Why the Body Needs Energy? Every living cell within the ...

    The action of the skeleton muscle pushes the blood through the vessels, therefore the valve within the endothelial layer of the vain to prevent a back flow of blood this is because the blood pressure is very low so the valves are essential (important)

  2. An investigation into the distribution of adult and juvenile limpets on a rocky shoreline.

    I am going to use a calliper to measure the base diameter of the limpet. Any limpets' base diameter is < 20mm will be considered as a juvenile whereas >20mm would be considered as an adult limpet. Method 1. Once I get to the shore at about 11:30 am, it will be a period of low tide.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work