Functions of Cell Parts, Multicellular Organisms, and Neuron Cell Structure and Function

This article discusses the functions of various parts of the cell, different levels in multicellular organisms, and neuron cell structure and function. It also covers the concept of water potential and different substances moving across the cell membrane. The subject covered is science and the course code is TT HCP1 HCP2 HCP3 HCP eve.

science TT HCP1 HCP2 HCP3 HCP eve

Table of Contents
MAIN BODY...................................................................................................................................2
LO2..................................................................................................................................................2
2.1Functions of various parts of the cell......................................................................................2
2.2Different level in multicellular organisms..............................................................................3
2.3Neuron cell: structure and function.........................................................................................4
LO3..................................................................................................................................................6
3.1Different substances moving across cell membrane...............................................................6
3.3Concept of water potential.....................................................................................................7
REFERENCES................................................................................................................................1
MAIN BODY
LO2
2.1 Functions of different parts of the cell
A Eukaryote cell is defined as an organism that has more than one nucleus in its lifetime.
It possesses various structures such as the nucleus, chloroplast, golgi, mitochondria, vacuole
(Jang and et.al., 2020) . These structures are covered by a cell membrane and further surrounded
by the cell wall. Each structure has its own function in the cell which are:
Nucleus- It is a specialized structure which is found in every cell. It has a membranous network
which has pores that permits entry of molecules. Its function is to control and regulate the
activities such as the metabolism and growth of the eukaryote cell. It also carries the hereditary
information and the genes(El-Aouar Filho and et.al., 2017). Its primary function is to store the
DNA of the cell and facilitates its replication and transmission by maintaining its integrity. Its
functions help its structure to regulate the growth activities of the cell.

Endoplasmic reticulum- It is a network in the cell membrane through which the molecules and
proteins move. The general function of reticulum is to produce enough proteins for the cell to
perform it functions effectively.
Ribosomes- When proteins are assembled at organelles it is known as ribosomes. When proteins
are being exported from the cell, the ribosomes attach it to the endoplasmic reticulum by
providing a rough surface. The function of ribosomes helps in providing its a rough base to the
reticulum.
Mitochondria- These are also known as the power house of the cell. Its primary function is to
perform cellular respiration and oxidizing the food that is being provided to the eukaryote cell.
With effective functioning, it helps the structure of cell membrane in getting energy through
oxidization of food. Mitochondria produces energy for cell where as lysosomes helps in
recycling waste material. It helps in breaking down fuel molecules and capturing energy in
cellular respiration. Chloroplast and lysosomes are having link as it helps in covert energy in
food to energy the cell can use. Three main functions of Mitochondria are: produce the energy
currency of the cell, ATP through respiration, and to regulate cellular metabolism. Development
of ATP is important as it is a energy currency ball of cell.
Chloroplast- These are only found in plant cells because these are the organelles that uses
photosynthesis process and converts the light energy into chemically stable energy which is
reliable. Its primary function is to conduct process of photosynthesis. In other words it can be
said that, The main function of chloroplasts is to convert light energy into relatively stable
chemical energy with the help of photosynthetic process. It is one of the main processs as it helps
in sustaining life on earth. And also functions as like amino and fatty acid in the synthesis. Once
the sugar is made through photosynthesis then it is broken down by the mitochondria to generate
energy. Because animals get sugar from the food they eat there is no need chloroplast to generate
sugar.
Lysosomes helps in breaking down food and other materials. All these are linked with each other
and work together. To generate cells in which they live they need help of each other and support.
with the help of lysosomes food and other material is break down. Lysosomes main function is in
digestive system of the cell and helps in serving to both degrade materials that are being taken up
from outside of the cell and digestion obsolete components of cell itself.

2.2 Different level in multicellular organisms
For the need of survival there are various parts in which a multicellular organisms are
divided (Nelson, P. and Masel, J., 2017). There are four level of organisation in which it is being
divided which are cells, organs, tissues, and organ system.
1. Cell: The first level of organisation in the multicellular organism is the cell and it the
most basic level. Cell is one of the most smallest unit that is capable of reproduction.
Based on the organism, cell vary in its function and structure. Cells may be of two kinds
that is prokaryotic and eukaryotic.
2. Tissues: The second level is the tissues. These are a set of same cells with same origin
which carries out specific functions collectively. Tissues of a human body consists of
four types that are muscle tissue, connective tissue, nervous tissue and epithelial tissue.
3. Organ: The third level in the organisation are the organs. These are structures which are
made up of various different tissue that works together to perform different functions of
the body. Many organs consist of tissues like stroma, epithelial and parenchyma. Organs
vary in size, shape and complexity for example heart, lungs, brain etc.
4. Organ system: The fourth level is the organ system which means a set collection of
various organ that work together to perform similar functions. In human body there are
total 11 organ systems that has their own specific functions.

2.3 Neuron cell: structure and function
These are the nerve cells that receives and send signals to the brain. While these cells
have a lot of similarity with other type of cells but it is functionally and structurally unique.
Depending on their location and role they differ in shape, structure and size (Fagan, M.B., 2017).
However, every neuron has a three basic parts that is a cell body, dendrites and axon. The cell
body is the core of a nerve cell that is also known as soma. It carries genetic information and
provides energy to the cell to drive its activities. An axon is a structure that is shaped like a long
tail that joins the cell body at a specific junction which is called as the axon hillock. Generally
neurons have one major axon. Dendrites are the fibrous roots that branches out from the cell
body. These act as antenna that receives and processes the signals that are received through the
axon.
The are various functions of the neuron cell that is:
 The primary function of the nerve cell is to transmit messaged from the brain and send it
to the receptor organs.
 Also, it helps in carrying stimulus to the spinal cord and the brain by the helps of sensory
nerve cells. Further, it helps in transferring these responses by motor neurons to the
specific organs.
There are various organelles that are present in the neuron cell one of the example of
which is the mitochondria. It is a part of cell that is responsible for sourcing energy. The brain is
one of the most active tissue in the body metabolically. Therefore, neurons need at most energy.
That is a normal brain uses around 40 ml of oxygen in a minute. Mitochondria uses this oxygen
and then produce energy for the cell.

SOURCE: Suzanne Wakim, 2020.
LO3
3.1 Different substances across cell membrane
Cell membrane allows various substances such as water, oxygen, carbon dioxide to pass
through the membrane. But it does not allow large molecules such as sucrose, starch, glucose to
directly enter into the membrane (Zhou and et.al., 2018). There are two ways in which the
transport of these substances can be done that is through passive and active transport which
includes diffusion, osmosis, facilitated diffusion and active transport.
 Diffusion- It is defined as movement of particles from grater concentration area to the the
less concentrated areas. The molecules in the solid, liquid and in gas are always in
constant motion because of their kinetic energy. The constant movement cause collision
and many things diffuse. For example; nutrients diffuses through blood tissues to blood.

SOURCE: Mandeep Grewal,2020
 Osmosis- It is a type of diffusion that is used for water transportation from high
concentrated water area to the low concentrated water area.
 Facilitated diffusion- Large molecules such as hydrophilic molecules and charged ions
substance cannot be simply diffused across a cell membrane. Special proteins in the cell
membrane are used to diffuse these molecules known as the transport proteins. And this
process of diffusion is known as the facilitated diffusion.
SOURCE: Mandeep Grewal,2020
Phagocytosis refers to the process for ingesting and eliminating particles. These includes,
microorganisms, foreign substances, apoptotic cells. This is the part of immune system and there
are several types of cells of immune system performs. This allows cells of immune system to

know what they are fighting against. Active transport refers to the process of moving molecules
across a cellular membrane with the use of cellular energy. There are two types of active
transport such as primary and secondary active transport.
3.3 Concept of water potential
Water potential measures the concentration of water molecules. It is a measure of
tendency that transfer free molecules of water to another area (Wang and et.al., 2017). This
transfer takes place through osmosis that is it diffuses water from the high concentrated area to
the less concentrated area. This helps in stabilising the internal movement of water ans also help
in stabilising the intracellular fluid level within the cell membrane. Thus, it helps in maintaining
and balancing the mechanical structure of the cell.

REFERENCES
Books and journals
Jang and et.al., 2020. Access to faster eukaryotic cell labeling with encoded tetrazine amino
acids. Journal of the American Chemical Society. 142(16). pp.7245-7249.
El-Aouar Filho and et.al., 2017. Heterogeneous family of cyclomodulins: smart weapons that
allow bacteria to hijack the eukaryotic cell cycle and promote infections. Frontiers in
cellular and infection microbiology. 7. p.208.
Nelson, P. and Masel, J., 2017. Intercellular competition and the inevitability of multicellular
aging. Proceedings of the National Academy of Sciences, 114(49), pp.12982-12987.
Fagan, M.B., 2017. Stem cell lineages: between cell and organism. Philosophy, Theory, and
Practice in Biology. 9(6).
Zhou and et.al., 2018. Effective nerve cell modulation by electrical stimulation of carbon
nanotube embedded conductive polymeric scaffolds. Biomaterials science. 6(9).
pp.2375-2385.
Wang and et.al., 2017. The effect of plasma treated PLGA/MWCNTs-COOH composite
nanofibers on nerve cell behavior. Polymers. 9(12). p.713.
Online references
A, B., 2018. [Online]. Available through <>
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