General Structure And Functions Of The Plasma Membrane

Decent Essays
General structure and functions of the plasma membrane

The plasma membrane acts as the partition between the cell and its exterior environment. It is made out of a bilayer of phospholipids with proteins and cholesterol embedded. The phosphatidylcholine is the most common phospholipid in cell membranes and is made out of a glycerol backbone to which a choline-phosphate group is attached to and two fatty acid tails (Alberts, 2009). The bilayer also contains cholesterol to maintain the fluidity of the membrane, which can also be enhanced or reduced depending on the amount of unsaturated fatty acid chains. The double carbon bond causes a kink in the chain which increases the fluidity of the membrane (Brooker, 2013). The proteins embedded to the
…show more content…
These proteins regulate most of the membrane’s functions including the main,which is the control of entry and exit of different molecules, ions and water, however the plasma membrane has several other roles contributing to the coordination of an organism. For example, transmembrane proteins have a few functions, which include the attachment to the cytoskeletal filaments of the cell, which restricts movement of those proteins. This is particularly important for the maintenance of the protein structure of an erythrocyte. The cytoskeleton of the red blood cell is formed from a hexagonal lattice of spectrin protein which has 4 subunits, with actin filaments at the connections. This cytoskeleton is linked to macro-complexes, which are made out of the interactions of transmembrane proteins and cytoskeletal proteins. The disruption of this can cause changes in the structure of the erythrocyte and …show more content…
This allows maximisation of efficiency of those reactions by concentrating metabolites and enzymes in a small, well defined space of the cell. These are tightly managed by lipid membranes, which are different to the phospholipid bilayers. (Finean, Coleman and Michell, 1984) An example of compartmentalisation or so called spatio-temporal regulation can be the way in which second messengers are aligned in the cell to allow efficient reactions. The 4 most studied second messengers are cAMP, cGMP, NO and Ca2+ .(McCormick and Baillie,

Related Documents

  • Great Essays

    Texas Red Lab Report

    • 1049 Words
    • 5 Pages

    Abstract This experiment was a study of the different properties of a lipid bilayer. We used fluorescent microscopy to study the lateral diffusion of lipids and binding properties biotin and anti-biotin. The effect cholesterol has on the fluidity of the membrane was tested using Fluorescent Recovery After Photobleaching (FRAP). We used a Nikon Eclipse 50i upright fluorescent microscope with a Digital Sight DM-2MBW CCD camera to take images of the bilayer after photobleaching.…

    • 1049 Words
    • 5 Pages
    Great Essays
  • Improved Essays

    Unit 11 Physiology

    • 1454 Words
    • 6 Pages

    Level 3 Applied Science Unit 11 physiology of Human Body Systems Task 1: ORGANELLE DIAGRAM FORM FUNCTION Nucleolus • The nucleolus is a darker staining region of the nucleus. It is non-membrane bound structure composed of ribonucleic acids (RNA) and proteins. It makes ribosomes inside the nucleus and contains all the DNA of the cell.…

    • 1454 Words
    • 6 Pages
    Improved Essays
  • Superior Essays

    The outer membrane is surrounded by special phospholipids composed of fatty acids called lipopolysaccharides that are attached to a glucosamine…

    • 1154 Words
    • 5 Pages
    Superior Essays
  • Improved Essays

    Physiology Lab Summary

    • 1753 Words
    • 8 Pages

    The quantity of this is known as the end- diastolic volume. 4. In S2 is the occurrence of ventricular filling, when the semilunar vale closes and the AV valve opens. 5. Red Blood Cells have a protein, which is hemoglobin, oxygen binds to the hemoglobin and is transported from the lungs to the cells throughout the body.…

    • 1753 Words
    • 8 Pages
    Improved Essays
  • Improved Essays

    This means the concentration gradient allows carbon dioxide to diffuse out of the blood and into alveolar air. The importance of this movement is to supply the cells of the body with a continuous supply of oxygen for respiration to occur and to remove carbon dioxide generated by respiration. Diagram B is a active transportation through the Plasma Membrane: Diffusion is the process that allows dissolved substances to pass through the cell membrane. Diffusion occurs when molecules spread, it moves from a region of high concentration to a region of low concentration. The importance of diffusion through the plasma membrane is to help with the release of ATP(Adenosine Triphosphate) during the release of energy.…

    • 750 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    Cell Membrane Case Study

    • 1161 Words
    • 5 Pages

    1) Richard is remodeling his room. He wants to know which tile is the strongest and that will last the longest. To test the experiment, Richard will drop a 1lb rock, 2lb rock and a 6lb bowling ball. Whichever tile that breaks he will not use, and the most durable one, he will use. The independent variable is the durability and the dependent variable is the weight Richard will be putting one, since its changing.…

    • 1161 Words
    • 5 Pages
    Improved Essays
  • Decent Essays

    Cholesterol has a unique structure that includes four linked hydrocarbon rings forming the steroid structure. The hydrocarbon tail links to one end of the steroid and a hydroxyl group linked to other end. While the hydroxyl group is able to form hydrogen bonds with nearby carbonyl oxygen of phospholipid. Additionally, cholesterol is an amphipathic macromolecule because it has a water-soluble polar region that dissolves in water, but almost the entire is non-polar which does not dissolves in water. It is also embedded in bilayer and serves a variety of functions in the human body which includes such as regulating membrane fluidity in animals.…

    • 338 Words
    • 2 Pages
    Decent Essays
  • Improved Essays

    Organelle Failure Nucleus: The nucleus of a cell is, without doubt, one of the most important parts of the cell. The nucleus instructs every single part of the cell what to do, and what the different organelles need to do. The nucleus includes chromatin (protein and DNA). It also contains Nucleolus (nucleoli is plural).…

    • 284 Words
    • 2 Pages
    Improved Essays
  • Great Essays

    This is an extension of the plasma membrane that will surround a particle outside the cell forming a vesicle. t. Pseudopod 19. The function of the cytosol is. u. Location of chemical…

    • 2321 Words
    • 10 Pages
    Great Essays
  • Improved Essays

    City brings her 6-year-old child to see her primary care physician, complaining that her child has seemed “off” for the past month. The child has been extremely fatigued and taking multiple naps during the day that do not seem to refresh her. She is normally a good sleeper at night and recently has begun to have trouble with multiple awakenings. The child has also complained multiple times of frequent headaches throughout the week. She has also been seen to exhibit some confusion while playing in the woods in their backyard with her friends.…

    • 942 Words
    • 4 Pages
    Improved Essays
  • Great Essays

    Osmosis Theory

    • 1862 Words
    • 8 Pages

    The actual membrane is created up of phospholipids which naturally form a bilayer, these phospholipids have a head that are hydrophilic and two fatty acid tails that are hydrophobic, and this allows water molecules to pass between the phospholipid molecules by osmosis and allowed self-orientating properties. It’s more than just a passive envelope; it is a dynamic structure that is actively involved in cellular activities such as cell signalling, cell-cell recognition and of course hydration. Another process important in cells is active and passive transport, which is the biological process that moves oxygen, water and nutrients into cells and remove its waste products. The difference between them is that active transport requires chemical energy as it is the movement of those chemicals from areas of lower concentration to areas of higher concentration while on the other hand passive transport requires no energy as it is the transportation of biochemical from areas of high concentration to low concentrations. In the report, active transport is the one which will be demonstrated as it is the transportation of low-to-high concentration.…

    • 1862 Words
    • 8 Pages
    Great Essays
  • Superior Essays

    They are known as the outer and inner membranes. The inner membrane surrounds the stroma and grana other words known as stacks of thylakoids (NCBI, 2016). Endoplasmic reticulum: Its main function is translation and folding of new proteins across the ER membrane. Its structure is made up of a single membrane system (BSCB, 2016).…

    • 1388 Words
    • 6 Pages
    Superior Essays
  • Improved Essays

    Draw and label a simple diagram of a phospholipid molecule (2) Why are the phospholipid molecules arranged in a bilayer? (2) So the hydrophilic phosphate groups are both orientated towards the water present on the outside and on the inside of the cell What is the role of the phospholipid bilayer? (1) To act as a barrier to the entry of water soluble molecules such as glucose which can only cross membranes through protein channels Why is the term “fluid-mosaic” used to describe cell membrane structure? (2)…

    • 568 Words
    • 3 Pages
    Improved Essays
  • Great Essays

    Membrane Self-Assembly Processes: Steps Toward the First Cellular Life by Pierre-Alain Monnard & David W. Deamer Summary: To summarize, early cells must have had a membrane to encapsulate its components and keep them within the cell. This membrane was made up of amphiphiles. This membrane was very permeable and as a result, passive diffusion occurred. Later on this membrane evolved to be a little impermeable as to keep the metabolic reactions and catalysts that drive these reactions within the cell. The membranes were also heterozygous in that it was made of more than one amphiphile.…

    • 1459 Words
    • 6 Pages
    Great Essays
  • Improved Essays

    Henceforth, fat, or lipids, is basic since it encompasses the greater part of the cell membranes. Lipids take into consideration the trading of supplements. It is important for these membranes to stay healthy and fit, all together for the cerebrum to be at its most extreme working potential. The core is contained by two membranes (an inward and an external).…

    • 1691 Words
    • 7 Pages
    Improved Essays