Structure and function of prokaryotic and Eukaryotic cells
A cell is a basic building block of all the living beings. (Encyclopaedia, The Dorling
Kindersley).
Every cell is a microscopic factory, carrying out loads of chemical reactions in a fully
supervised manner to perform all the functions of the living body.(nature) it has four
main common components, called plasma membrane(an outer covering which
separates the interior of the cell from its surrounding environment),cytoplasm(gel like
region where all the other organelles are present),DNA(genetic material) and
Ribosomes(responsible for protein synthesis).structure of cell membrane is related to
its amazing function in terms of transportation in way that it is valuable in fluidity(fluid
mosaic model where protein is suspended in double layer of phospholipids).proteins,
also known as enzymes here in cell membrane are responsible for selectively
exchanging substances(nutrients uptake and removal of toxic waste)communicating
with the environment, controlling biochemical reactions(signal transduction, energy
production) and bonding a connection between cells. Whereas the phospholipid part
of the structure of cell membrane isolates cell contents.
Figure1: Structure of the cell (MSD manual)
A cell can be grouped into two vast categories known as prokaryotic and eukaryotic
cells.
Prokaryotes derived from Greek word(pro) stands for before and karyon means
nucleus. Life of prokaryotes started over 4 billion years ago, feeding on carbon dioxide
CO2, carbon mono oxide CO, steam, nitrogen, atmospheric ammonia, and hydrogen.
These are smaller and simpler in structure and contains 2 of 3 domains of life, bacteria,
and Archaea (single celled organisms that congregate their double stranded DNA
genome in a nucleoid area). these species live freely or found in pathogens(diseases)
or mutual combination with hosts either intra or extracellular.it reproduces by binary
fission, but in few cases budding also occurs. Prokaryotes like cyanobacteria may form
large colonies while myxobacteria goes through multistep life cycles.
(science direct.com)
Genetic material floats freely in prokaryotes while other cell organelles are not bound
by membranes. Its genomics has a potential application in medicine and industry.
Aerobic respiration which is an amazing flexible respiratory system makes prokaryotes
to adjust with different harsh environments. Mode of metabolism (aerobic and non-
aerobic with and without oxygen) gains its energy from chemical sources that are fatal
to living things. Also, they shape biotic and abiotic feature of the planet.
