Essay On Cells

About Cells Essay
About Cells Cell, smallest unit of an organism that can function independently. All living
organisms are made of cells, and it is generally held that nothing less than a cell can truly be said to
be alive. Some microscopic organisms, such as bacteria and protozoa, are single cells whereas
animals and plants are composed of many millions of cells assembled into tissues and organs.
Although viruses and cell–free extracts are able to perform many individual functions of a living
cell, they lack the capacity shown by cells of independent survival, growth, and replication and are
therefore not considered...show more content...
All cells host a variety of chemical reactions that enable them to grow, produce energy, and eliminate
waste. Together these reactions are termed metabolism (from a Greek word meaning "change"). All
cells contain hereditary information, encoded in molecules of deoxyribonucleic acid (DNA), that
directs the cell's activities and enables it to reproduce, passing on its characteristics to its offspring.
These and other numerous similarities (including many identical or nearly identical molecules)
demonstrate that there is an unbroken continuity between modern cells and the first primitive cells
that appeared on Earth.
Chemical Composition
There is nothing in living organisms that contravenes chemical and physical laws. The chemistry of
life, the subject of biochemistry, is based overwhelmingly on carbon compounds and almost
exclusively on chemical reactions that take place in aqueous solution in a narrow range of
temperatures–those experienced on Earth. The chemistry of living organisms is much more
complicated than any other chemical system known. It is dominated and coordinated by enormous
polymers–molecules made from chains of linked chemical subunits–the unique properties of which
enable cells and organisms to grow, reproduce, and so on. These large polymeric molecules, or
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Plant Cell Structures
Name: Ezeugo Okechukwu David
Date: 5/16/17
Instructors name: Mathew Routh
Assignment: SCIE207 Phase 2 Lab Report
Title: Animal and Plant Cell Structures
Animal cell
NumberCell structureDescription and Function
1Nuclear pore This is a protein lined channel or Microscopic channel which allows ions and small
molecules in and out of nucleus
2Chromatin (DNA)It consists of DNA and histones, it helps to put the DNA into a small Volume
and serves as a body that helps to control DNA and expression.
3NucleolusIt is located inside the nucleus of eukaryotic cell and sits in the nucleus and assembles the
ribosomes
4Nuclear envelopIt separates the nucleus from cytoplasm in the eukaryotic cells and It encloses the
nucleus and allows content to move...show more content...
16Peroxisomes Organelle present in the cytoplasm of many cells, bound by a single membrane and
roughly spherical.
17Plasma membrane Every living cells possess a plasma membrane which encloses their content.
18CentriolesAn organelle which is made up of protein strands called microtubules. that makes
copies of themselves and helps divide cells
19Golgi bodyA layered organelle located near the nucleus which is present in most eukaryotic cells.
It processes a bundle lipids and protein as they are synthesized within the cell
20Centrosome An organelle located inside the nucleus of a cell which are made from two centrioles.
They help to organize microtubules which are utilized during cell

Essay On Hair Cells
Hair cells are alive and must have an appropriate nutrition. Human beings have 100 to 150
thousand strands of hair; each one grows almost 13 cm (5 inches) in 5 to 6 years. When each
strand dies, the period for regrowth lasts almost 4 months. Keratine is the main fibrous proteine of
the hair made of amino acids such as sulfur containing cysteine and methionine. The disulfide bonds
are abundantly present in curly hair as disulfide bonds. Perms and relaxing treatments take
advantage of these disulfide bonds to change the structure of the hair. Who has curly hair and wants
it straight, with the use of chemical solutions that can break up or "relax" these bonds it is possible
reaching the goal. The shape of our follicles is also...show more content...
Hair loss that runs in the family can be treated with medicines or hair transplant surgery. When
hair loss is inherited, the hair won't grow back naturally, treatment can help some hair grow back,
but not all of it. If diseases, medicines, stress, or hair damage causes the hair loss, it often will
grow back after the cause is taken away. * Trichotillomania (TTM), the hair pulling disorder, is
characterised by the urge in the pulling out of one's own hair, this could run in family or be caused
and triggered by trauma and stress. This occurs to such a degree that leads to the hair loss. The hair
on the head and the hair around the eyes (eyebrow and eyelid) are most commonly being attacked. In
this case the medications clomipramin and N–acetylcysteine which is a glutamate modulator could
be helpful along with psychotherapy. *Acne is a very common and disturbing condition that
involves a big portion of the people especially in puberty. The treatmaent, diagnosis and cure of it is
quite difficult and a dermatologist must consider numerous factors such as age, gender, hormonal
function, wealth, nutrition, stress, cosmetics and soaps that are being used, blood values, and a few
more details. When it comes to the cure there are different medications; tetracycline, corticosteroids,
retinoids, azelaic acid, azitromycine, rifampin, and chloramphenicol are part of the medications

Biology Cell Parts Essay
Nucleus– "the brain" or control center of the cell. The Nucleus, a membrane–bound structure of a
cell, plays two crucial roles in controlling the cell. The nucleus carries the cell's genetic information
that determines if the organism will develop, for instance, into a tree or a human; and it directs most
cell activities including growth, metabolism, and reproduction by controlling protein synthesis. The
presence of a nucleus distinguishes the more complex eukaryotic cells of plants and animals from
the simpler prokaryotic cells of bacteria and cyanobacteria that lack a nucleus. The nucleus is the
most predominate structure in the cell. It is typically round and occupies 10% of the cells total
volume. The nucleus is wrapped in a...show more content...
Chromatin– a collection of separate structures called Chromosomes. Within the nucleus the DNA is
organized along with proteins into Chromatin. During Mitosis, the chromosomes condense into what
is known as Chromosomes, which allows the genetic information of the previous cell to be passed on.
Chromosome– Chromosomes are the microscopic structure within cells that carries the molecule
deoxyribonucleic acid. DNA is the hereditary material that influences the development and
characteristics of each organism. In bacteria and bacteria–like organisms called archaebacteria,
chromosomes are simple circles of DNA that float around in the cell. In more complex cells, or
Eukaryotes, chromosomes are stored within a well developed and defined nucleus. In eukaryotic
cells, chromosomes are highly complex structures in which the shape of the DNA molecules is
linear, rather than circular. Chromosomes consist chiefly of proteins and DNA. Tiny chemical
subunits called nucleotide bases form the structure of DNA. A sequence of these bases that are
along a DNA strand will create a code for the production of a special protein also known as a gene.
Genes occupy precise locations on the chromosome. Each cell contains enough DNA to form a
thread extending about 2 m (about 7 ft). Proteins called histones play a key role in packaging DNA
within chromosomes. Sections of

Prokaryotic Cells Essay
Prokaryotic Cells
All living things are made of cells, and cells are the smallest units that can be alive. Life on Earth is
classified into five kingdoms, and they each have their own characteristic kind of cell. However the
biggest division is between the cells of the prokaryote kingdom (monera, the bacteria) and those of
the other four kingdoms (animals, plants, fungi and protoctista), which are all eukaryotic cells.
Prokaryotic cells are smaller and simpler than eukaryotic cells, and do not have a nucleus.
Prokaryotic means 'pre–nucleus' and eukaryotic means 'true nucleus'. The nucleus in eukaryotic cells
contains the DNA in linear chromosomes and is bounded by a nuclear membrane, but since...show
more content...
The cell membrane is made of phospholipids and proteins, like eukaryotic membranes, and controls
the entry and exit of substances into and out of the cell. The mesosome is a tightly folded region of
the cell membrane containing all the membrane–bound proteins required for respiration and
photosynthesis. The flagellum is a rigid rotating helical–shaped tail used for propulsion. The motor
is embedded in the cell membrane and is driven by a H+ gradient across the membrane. A
clockwise rotation drives the cell forwards, while an anticlockwise rotation causes a chaotic spin.
This is an example of a rotating motor in nature. The prokaryotic flagellum does not have the
same the same structure as eukaryotic flagellum. The cytoplasm contains all the enzymes needed
for all metabolic reactions, since there are no organelles. Nutrients and reserves may be stored in
the cytoplasm in the form of granules of glycogen, lipids, polyphosphate, or in some cases,
sulphur or nitrogen. The ribosomes are for protein synthesis just like eukaryotic ribosomes but
they are smaller than eukaryotic ribosomes. Plasmids are small circles of DNA, which carry
additional genes and are used to exchange DNA between bacterial cells. DNA is always circular,
and not associated with any proteins to form chromatin, it carries the genes for the proteins the cell
needs. Prokaryotic cells do not have membrane bound organelles, like

Essay about The Cell
The cell is the fundamental structural unit of all living organisms. Some cells are complete
organisms, such as the unicellular bacteria and protozoa; others, such as nerve, liver, and muscle
cells, are specialized components of multi–cellular organisms. Cells range in size from the smallest
bacteria–like mycoplasmas, which are 0.1 micrometer in diameter, to the egg yolks of ostriches,
which are about 8 cm (about 3 in) in diameter. Although they may differ widely in appearance and
function, all cells have a surrounding membrane and an internal, water–rich substance called the
cytoplasm, the composition of which differs significantly from the external environment of the cell.
Within the cell is genetic material, deoxyribonucleic acid...show more content...
All cells are dynamic at some stage of their life cycle, in the sense that they use energy to perform a
variety of cell functions: movement, growth, maintenance and repair of cell structure, reproduction
of the cell, and manufacture of specialized cell products such as enzymes and hormones. These
functions are also the result of interactions of organic molecules.
Plasma Membrane
The plasma membrane, a continuous double layer of phospholipid molecules 75 to 100 angstroms
thick, constitutes the boundary between the cell and its external environment. In addition to lipids,
the plasma membrane has protein components (polypeptides) that are associated with either the
outer or inner surfaces of its layers or are buried within them. The structure as a whole is selectively
permeable, or semipermeable; that is, it permits the exchange of water and selected atoms and
molecules between the cell exterior and interior. This is vital to the cell because while the plasma
membrane helps maintain high local concentrations of organic molecules within the cell, it also
allows interaction between the cell and its external environment.
The plasma membrane mediates such interactions in various ways. The exchange of mineral ions
and small nutrient molecules is controlled by plasma membrane proteins that act as pumps, carriers,
and channels. The plasma membrane also participates in the exchange of larger molecules through
phagocytosis, the

Eukaryotic Cells Essay
Eukaryotic Cells The cell may be regarded as the basic unit of an organism, it carries out the
essential processes that make the organism a living entity. All cells share certain structural and
functional features and they are of almost universal occurrence in living organisms. Biologists have
devoted a great deal of attention to its structure and the processes that go on inside it. They have
recognised a major distinction between two types of cells, Eukaryotic cells that have a nucleus and
Prokaryotic cells that do not have a nucleus. There are many other differences between these two
cells, in particular eukaryotic cells have a full complement of membrane...show more content...
The formation of the proteins and phospholipids is called the lipid bylayer. The proteins take the
form of globules dotted about in a mosaic pattern with some being attached to the urface of the
membrane while others penetrate into it to varying extents. Some of these proteins act as enzyme
catalysing chemical reactions within the membrane and also as pumps and channels transporting
molecules into and out of the cell. The plasma membrane is perforated by pores and allows
substances to pass in and out of the cell by Diffusion Active Transport, osmosis, Endocytosis and
Exocytosis. The external cell membrane contains lipids and proteins combined with sugar
molecules called Glycolipids and Glycoproteins. The sugar molecules only attach to the outside of
the cell membrane and form what is known as the Glycocalyx or cell coat. The Glycocalyx is
sticky and enables animal cells to adhere to each other. In the development of organisms cells must
migrate from one region to another and recognise what kind of cells are their proper neighbours and
what kinds are not. This recognition ability appears to lie within the Glycocalyx.
The endoplasmic reticulum is found in the cytoplasm of the cell and like the plasma membrane is
composed of phospholipids and protein. ER is an intracellular transport system moving materials
from one

Cell Theory
1.Cell Theory is an explanation that says everything is made of cells. It continues on to say that
those cells came from preexisting cells. Cell Theory is a theory because it is a frame–worked
explanation of an observation made by many biologists like Anar Van Leeuwenhoek. Van
Leeuwenoek studied plant stems, pond water, and gathered a conclusion that generally, all of those
things are made of cells. Other biologists like Louis Pasteur added onto this idea that all organisms
are composed of cells. Atheory is also composed of two components; a sequence of patterns in the
world and the thing or catalyst that is responsible for the pattern. The sequence of the pattern in Cell
theory is that every organism in the world are made up of cells....show more content...
The fatal flaw in my experiment of cloning a single plant, creating a population of 100 plants that are
genetically identical, and raising these plants in identical environments with no variation in traits is
that there is no variation to show any difference(s) in the experiment.
3.A salt crystal dropped into a beaker of water becomes smaller and eventually seems to disappear.
However, the same salt crystal remains intact at the bottom of a beaker of octane because Sodium
Chloride is ionic and would get attracted to the water. The octane is hydrophobic and has nothing
for the salt crystal to bond with. The water is polar and hydrophobic, which gives the salt the ability
for the oxygen atoms in the water to be attracted to the Sodium ion, and the hydrogen atoms to the
chloride ion.
4.Molecules with carbon–carbon bonds have more potential energy and lower entropy than carbon
dioxide because the carbon to carbon bonds are held together loosely. Because the carbon to carbon
bonds are held loosely together, the bond has low entropy, high potential energy, and more usable
energy. The Carbon dioxide is held tightly together, has high entropy, and will have low potential
energy because the charges will be attracted to the oxygen. This results in the carbon dioxide to have
less usable

Essay on Cells and their parts
Cells are some of the smallest organisms around. All living things consist of cells, and yet they are
invisible to the naked eye. Cells are the basic structural and functional units of life. Cells are made
up of many different parts which allow them to function properly.
All cells are separated from their surrounding by a cell membrane. The cell membrane regulates what
enters and leaves the cell and also aids in the protection and support of the cell. A cell membrane is
similar to the walls surrounding your house.
In plants the cell membrane is surrounded by a cell wall. The cell wall is outside the cell
membrane, and its purpose is to help the membrane protect and support the cell. Since the cell wall
is very porous, water, oxygen,...show more content...
Chromosomes contain the genetic information that must be passed to each new generation of cells.
Chromosomes are what you pass on to your children to make them who they are, it's the DNA of a
cell.
The cytoplasm is the area between the nucleus and the cell membrane. The cytoplasm contains many
important structures. This area is basically the main place where you will find structures that help
the cells stay alive.
Mitochondrion is an importance structure that lies in the cytoplasm area. Mitochondrion is the
plural word for mitochondria, which is the key organelle that converts energy from one form to
another. Mitochondria changes the chemical energy stored in food into compounds that are more
convenient for the cell to use. The mitochondrion contains two special membranes. The outer
membrane surrounds the organelle, and the inner membrane has many folds that increase the surface
area of the mitochondrion.
Ribosomes are the structures in which proteins are made. Cells that are active in protein synthesis
are often crowded with ribosomes. Ribosomes are composed of RNA and protein. Some ribosomes
are attached to the membranes, and some are free in the cytoplasm. Ribosomes are among the
smallest of organelles. They are no larger than 25 nanometers in diameter. A nanometer is equal to
one billionth of a meter.
Many cells are filled with a complex network of tube like things known as the endoplasmic
reticulum. The endoplasmic

Essay On Cells

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