This article needs additional citations for verification. Please help improve this basic cell biology pdf by adding citations to reliable sources.
Unsourced material may be challenged and removed. Cell biology explains the structure, organization of the organelles they contain, their physiological properties, metabolic processes, Signaling pathways, life cycle, and interactions with their environment. This is done both on a microscopic and molecular level as it encompasses prokaryotic cells and eukaryotic cells. Research in cell biology is closely related to genetics, biochemistry, molecular biology, immunology, and developmental biology.
These molecules within the cell, which operate as substrates, provide a suitable environment for the cell to carry out metabolic reactions and signalling. The cell shape varies among the different types of organisms, and are thus then classified into two categories: eukaryotes and prokaryotes. Cell biology focuses more on the study of eukaryotic cells, and their signalling pathways, rather than on prokaryotes which is covered under microbiology. The main constituents of the general molecular composition of the cell includes: proteins and lipids which are either free-flowing or membrane-bound, along with different internal compartments known as organelles.
This environment of the cell is made up of hydrophilic and hydrophobic regions which allows for the exchange of the above-mentioned molecules and ions. The hydrophilic regions of the cell are mainly on the inside and outside of the cell, while the hydrophobic regions are within the phospholipid bilayer of the cell membrane. The cell membrane consists of lipids and proteins, which accounts for its hydrophobicity as a result of being non-polar substances.
Therefore, in order for these molecules to participate in reactions, within the cell, they need to be able to cross this membrane layer to get into the cell. They accomplish this process of gaining access to the cell via: osmotic pressure, diffusion, concentration gradients, and membrane channels. Inside of the cell are extensive internal sub-cellular membrane-bounded compartments called organelles.
DNA, the building block of life. Nuclear Architecture is important for dictating nuclear function.
The growth process of the cell does not refer to the size of the cell, but instead the density of the number of cells present in the organism at a given time. Cells are the foundation of all organisms, they are the fundamental unit of life. The growth and development of the cell are essential for the maintenance of the host, and survival of the organisms. For this process the cell goes through the steps of the cell cycle and development which involves cell growth, DNA replication, cell division, regeneration, specialization, and cell death.