The structure and function of cell membrane







A cell can be explained as the basic unit, which supports the life. Organisms are made by one or more than one cell. In all cells, the cell membrane is standard, which is a thin structure, usually made among 5 to 10 nm wide, and it helps in separating the cell from the nearby environment. There are two essential functions of the plasma membrane (Yawata, 2006). The first function includes separation of cell contents through the surrounding by analysing what comes and go out of the cell. It plays a significant role in protecting the integrity of cell contents with the help of selective permeability (Hölzl & Fischer, 2012). The model of fluid mosaic shows the structure of cell membrane as flexible and includes the vegetable oil consistency like molecules float in the fluid medium in the way that allows the movement of sideways in the cell membrane. The question is how substances pass by using both passive and active transport in the cell membrane (Yawata, 2006). While cell membrane act as the hindrance, it often does it selectively (Murphy, Peer & Schulz, 2010). The cell membrane development permits few molecules to take the material, simultaneously, it also constrains the molecules movement. Therefore, cell membrane act as a barrier, which separates bot inner and the outer cellular environment. These substances move the membranes by both active as well as passive transport (Yawata, 2006).

Active transport relies on ATP, where else passive transport make use of particles kinetic energy for moving the plasma membrane (Murphy, Peer & Schulz, 2010). In passive transport, the cell fails to offer the energy input due to the molecules in the plasma membrane, which are used by kinetic energy. Passive transport is undertaken through the osmosis, diffusion and filtration (Bell & Grant, 1963).

Significance of membrane in the production of cell energy

The membrane is involved in the transduction of energy that’s also explained as the conversion process of energy from one place to the other place during the time of photosynthesis. In the photosynthesis process, the pigment of membrane absorbs the sun energy and then convert the same into chemical energy, which is later on stored in carbohydrates (Karp, 2009). The mechanism of such energy is included in the chloroplast and mitochondria membrane within eukaryotes. As membrane are not permeable for most of the solutes. In that case, gradients might be set up between the intracellular and extracellular sections (Karp, 2009). These gradient acts like an energy depositories, which is used in the work of thermodynamics.

How Nucleic acids are applied in cells

Nucleic acids that cover up ribonucleic acid (RNA) as well as deoxyribonucleic acid, which holds different roles within the cell (Murphy, Peer & Schulz, 2010). During the process of cell division, DNA is passed to the generation of a new cell by duplication, which exists between the cell nucleuses and is organised in the chromosomes (Buehler, 2015). It includes programmatic command and the same is needed for the activities of cellular. All these commands passed through the DNA. RNA is significant in the process of protein synthesis and is considered as the crucial element in cell ribosomes (Buehler, 2015). It is quite imperative to know that nucleic acids are formed by the nucleotide monomers, which cover up three parts, such as little carbon, a phosphate group, along with nitrogenous base (Murphy, Peer & Schulz, 2010). In the process of nucleic acid dehydration synthesis, the base of nitrogenous are connected, and then there is a loss of water molecule (Buehler, 2015).

Cell division process

The cell division term is mainly used while referring the mitosis. It’s the process by which new cells in the body are formed (Murphy, Peer & Schulz, 2010). However, meiosis is considered as another type of cell, which tries to produce their replica, during the process of mitosis, and it involves chromosomes. In this complete process, it seeks to produce two identical cells (Murphy, Peer & Schulz, 2010). As this entire process is critical, various genes mediate the involved steps (Murphy, Peer & Schulz, 2010). In case, when the cell division is not regulated in right way, cancer might occur. The most remarkable thing related with mitosis is the conformity as well as fidelity, by which DNA is transferred from single generation to the other generation, without the help of any dilution (Murphy, Peer & Schulz, 2010). The occurrence of cell division includes series of accurate time and is regulated through the growth stages, like replication of DNA and generation of two similar cells. DNA duplication along with cell growth mainly happen during the process of interphase and is closely followed by the mitotic phase (Murphy, Peer & Schulz, 2010). The chromosomes duplication includes segregation and then it’s categorised in nuclei at the time of the mitotic phase. Along with that, cytoplasm is categorised, and it produces two similar cells (Murphy, Peer & Schulz, 2010).

Cell division process


Gap 1: phase cell starts increasing in size and then nuclear starts breaking down. DNA of synthesis phase cell gets replicated, but if there is no copy of the genome, then cell don’t get divided (Alberts, 1989).

Gap2: Mitotic spindle, which is made through the cytokinesis are formed. Cell ensure that there is a right number of chromosomes as well as organelles (Alberts, 1989). In this stage, interphase gets end and division of cell are continued (Murphy, Peer & Schulz, 2010).

Cancer cells are the one that gets divided and then gets multiple. There are several differences between cancer and normal cells. Normal steps usually stop growing when the threshold is achieved. But cancer cells continuously produce, even in the presence of enough cells, which leads to a tumour. Normal cells usually look quite different from the cancer cells. Different from normal cells, cancer cells are uneven in both shape and size. The chemicals, which is used for killing cancer, even kills all the required cells. Cancer can even spread in the brain and lead to seizures and haemorrhage. As tumour also needs more blood; therefore, it can reduce haemoglobin in a drastic way.




Alberts, B. (1989). Molecular Biology of the Cell, Volume 1. Courier Corporation

Bell, D. J., & Grant, J. K. (1963). The Structure and Function of the Membranes and Surfaces of Cells: Biochemical Society Symposium No. 22 Held at the Middlesex Hospital Medical School, London, on 9 March 1962, Issue 22. CUP Archive

Buehler, L. (2015). Cell Membranes. Garland Science

Hölzl, D. F., & Fischer, W. H. (2012). The Dynamic Structure of Cell Membranes. Springer Science & Business Media

Karp, G. (2009). Cell and Molecular Biology: Concepts and Experiments. John Wiley & Sons

Murphy, A. S., Peer, W., & Schulz, B. (2010). The Plant Plasma Membrane. Springer Science & Business Media


Yawata, Y. (2006). Cell Membrane: The Red Blood Cell as a Model. John Wiley & Sons

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