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

fluid balance

Extracts from this document...


P4- Describe the processes by which materials move into and out of cells The first process I am going to write about is diffusion. The physics definition of this is intermingling of substances: the random movement of atoms, molecules, or ions from one site in a medium to another, resulting in complete mixing (http://uk.encarta.msn.com/dictionary). To explain this is in more detail it is when Materials move into and out of cells, it is also the movement of molecules from a region of high concentration to a region of low concentration. Molecules, atoms and ions are in a random constant motion and that this is most marked in gases but also in liquids, this is because they are further apart. ...read more.


For this to happen the concentration must be different; this is known as concentration gradient. Concentration gradient is the difference between opposing concentrations. The greater the concentration gradient, the rate of diffusion will be faster, however it will not happen instantly. This is because the numbers of molecules become more evenly distributed, but the net movement of molecules will slow down and eventually come to a stop. The cell membrane is a very selective "molecular gatekeeper". It contains a continuous layer of lipid and protein molecules that act as a selective barrier to regulate the cell's chemical composition. The passage of most dissolved substances is regulated via special protein molecules, called transport or carrier proteins, which are embedded within the thickness of the layer. ...read more.


Meanwhile, the carrier protein uses the energy to change its shape, or configuration, flipping the substance through the membrane and releasing it on the other side. Some substances, such as sodium and potassium ions, have their own dedicated carrier proteins and pumping mechanisms. (http://uk.encarta.msn.com/encyclopedia). Material will also move through the body because of osmosis. The physics definition of osmosis is slow change in concentration: the diffusion of a solvent through a semi permeable membrane from a dilute to a more concentrated solution (http://uk.encarta.msn.com/dictionary) so in a simpler term it is a net movement of water molecules through the cell membrane and then moves down the concentration gradient like diffusion. ?? ?? ?? ?? Carla Cooper Unit 13: Fluid Balance for Health and Social Care Task1 9th November 2007 6 ...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

    Effect of nitrate concentration on the growth of Duckweeds

    5 star(s)

    To increase the reliability of the results 30 replicates were pooled together to allow me to carry out a statistical test, these 30 replicates all started and ended the investigation. The major factors for survival of the plant were controlled as best as possible.

  2. the effect of bile concentration on the activity of the enzyme lipase during the ...

    milk has gone bad as it will turn very creamy and go rancid. This just means that we will have to repeat the experiment which will cause us inconvenience but has a very low possibility of altering our results Heat the milk in a thermostatically controlled water bath as the

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

    gives the position of the value Median = (n+1/2) gives the position of the value Upper Quartile = (n/4)*3) gives the position of the value Inter-Quartile Range = Upper Quartile - Lower Quartile Range = Highest value - Lowest Value Outliers = 1.5 (Inter-Quartile Range)

  2. the Effect of Copper Ions on a

    This is since there will be a greater number of active sites available for the starch molecules. Therefore there will a greater number of successful collisions per second and the rate of reaction will increase. 5. Iodine concentration and volume- 2 drops of 0.1M of iodine will placed in each

  1. Investigating the effects of different lead chloride concentrations on the growth of cress seedlings

    It disrupts mitosis, inhibits plant growth, inhibits enzymes, ATP synthesis and protein formation, chlorophyll synthesis, photosynthesis, water absorption, transpiration rate, and decreases pollen germination. Prediction I predict that the effect of lead chloride will hinder or completely stop the growth of the cress seedlings.

  2. Investigating the effects of Sodium Hydroxide concentration on Catalase

    gas syringe and starting the stop watch at the same time, and taking a reading every 5 seconds. The gas that will be produced and collected will be oxygen. I will also repeat each experiment for each concentration at least three so that I get an average and so that it will make my results more relievable.

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