Biology: Nucleus, Rough Endoplasmic Reticulum, Cell Membrane, Glycolipids, Cholesterol, Membrane Proteins, Transport Proteins, Carbohydrate Group, Bulk Transport

Running head: BIOLOGY
BIOLOGY
Name of the Student:
Name of the University:
Author note:

1BIOLOGY
Nucleus
The nucleus of the cell forms one of its most essential organelles, and is commonly
prevalent in the cells of eukaryotes. Due to its high level of specialization, the nucleus functions
as one of the key functional centers within the cell, exhibiting functions associated with the
processing of information and administration of essential activities of the cell (Caelro-Cuenca.
Janota and Gomes 2018). One of the major functions of the nucleus lies in it storage of the
genetic material of the cell, in the form of DNA molecules required for chromosomal formation,
known as histones. Additional functions of the nucleus include the ribosomal formation within
the nucleolus, participation in the transmission of hereditary data to the daughter cells from its
parent cells, maintenance of cellular metabolic activities through enzymatic regulation and
contribution to the growth and maturity of novel cells through chromosomal information
contained within itself (Hancock, 2018).
Rough Endoplasmic Reticulum
The rough endoplasmic reticulum is a organelle present in a cell’s endo-membrane
system. The organelle is a subtype of endoplasmic reticulum, and is emphasized by its studded or
rough features as compared to its smooth counterpart, due to the presence of ribosomes bound
within its membranes (Wang et al. 2015). The major functions of the rough endoplasmic
reticulum include the modification, synthesis and folding of essential proteins required for
deliverance across numerous other cellular organelles or for secretion from the cell. The rough
endoplasmic reticulum also works closely with the mitochondria and hence is also involved in

2BIOLOGY
the initiation of programmed cell death or ‘apoptosis, along with responding to the presence of
unfolded proteins (Phillips and Voeltz 2016).
Structure and Function of Cell Membrane: Fluid Mosaic Model
The cell membrane, otherwise also known as the plasma or cytoplasmsic membrane, is an
essential biological element of the cell concerned primarily with separating the internal cell
components from its external surroundings. In addition, the cell membrane is concerned with the
transportation of the cellular components, transmission of cellular signals, maintenance of the
potential of the cell as well as provision of specific shape to the cell by anchoring the
cytoskeleton (Raiborg and Stenmark 2016). In 1972, Garth L. Nicholson and S. J. Ginger stated
the fluid mosaic model in order to explain the structural components of the cell membrane. In
accordance to the model, the plasma membrane can be viewed as a mosaic of cholesterol,
carbohydrates, phospholipids and proteins, which imparts fluidity in the structure. The primary
structure of the cell membrane is comprised of molecules of phospholipids, which are
amphiphilic, possessing lipophilic and hydrophilic characteristics. The second components, is
composed of integral proteins, with complete embedding in the cell membrane followed by
interactions between hydrophobic areas of the phopholipid layer and the hydrophobic areas of
the proteins. The third section of the cell membrane consists of carbohydrates, present in the
exterior regions. These form either glycoproteins or glycolipids, through binding to proteins and
lipid components (Nicholson 2014).