Structure and Function of Cell Membrane: A Comprehensive Overview

Running head: ADVANCED CELL BIOLOGY
ADVANCED CELL BIOLOGY
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ADVANCED CELL BIOLOGY1
Introduction:
The cell membrane is said to have a main role in working for the cell as guarding
system between the single-celled organism and the ecosphere (Kosmalska et al. 2015). It is
believed that it has an important role for the cells to have different type of appearance which
gives permission to the cells to conduct communication with the cell membrane and the area
outside. The membrane of the cell is basically seen to be having a duple layer structure of
phospholipids which are fat-like substances having phosphorus in it (Sezgin, Levental, Mayor
and Eggeling 2017). Every layer of the membrane is made up of phospholipid particles which
has a hydrophilic head and a hydrophobic end tail (Ruan et al. 2016). The proposal of fluid
mosaic model was given just to describe the structure of the cell’s plasma membrane
structures as mosaic of different components (Zalba and ten Hagen 2017). The mosaic is
build-up of the phospholipids, proteins, cholesterol, and carbohydrates which all together
gives the plasma membrane a fluid nature. The assignment will focus on the fluid mosaic
model and interesting facts of the structure of the cell membrane (Shan and Wang 2015).
Figu
re1: Cell Membrane

ADVANCED CELL BIOLOGY2
(Source: Shi et al. 2018)
Structure of the cell membrane:
The cell membrane is seen to be a bunch of various types of proteins and lipids (Loew
2018). The lipids have an ability to make up wherever it is necessary from 20 percent to 80
percent of the cell membrane focusing on the location of the membrane and its role in the
cell, and also keeps the proteins as remainder (Harrison 2015). The lipids play a major role in
making the membranes flexible, whereas the proteins assess and regulates the chemical
climate of the cell and assist them in the moving out of the molecules through the membrane
(Xuan et al. 2016).
Phospholipids
Phospholipids builds the main structure of the cell membrane. Every single molecule
of a phospholipid consists of two different ends which is a head and a tail end (Fang, Kroll,
Gao and Zhang 2018). The head has the composition of a phosphate group which is in love
with the water which means that the molecule has a tendency to get attracted towards water
molecules and is called hydrophilic (Chen et al. 2016). Whereas the tail end is made up of
two threads of hydrogen atoms and carbon atoms which all together is called fatty acid chains
(Deisseroth et al. 2016). These fatty acid chains are scared of water or hypdrophobic which
states that they have a tendency to run away or avoid water molecules (Abedini, Schmidt and
Raleigh 2016). The concept of hydrophobicity is similar to the condition which happens
when oil droplets fall in to water. It is observed that the oil never mixes with water (Tan, Wu,
Zhang and Zhang 2015).

ADVANCED CELL BIOLOGY3
Figure 2: what are phospholipid also known as
(Source: Sezgin, Levental, Mayor and Eggeling 2017).
The cell membrane is seen to have a composition of the sterols and glycolipids. One
of the most important sterol is the cholesterol, which has a major role of regulating the
flexibility of the cell membrane present in the animal cells (Zhou et al. 2015). It has been
found that decreased composition of cholesterol present in the cell membranes makes it more
fluid in nature, but it also increases its permeability to other molecules (Abedini, Schmidt and
Raleigh 2016). It can be said that the total amount of cholesterol composition in the
membrane is functions to maintain the cell’s permeability thus making it capable to permit
the entry of the exact amount of molecules (Vance 2015).