Notesale: Turn your study into money

Document Preview

Extracts from the notes are below, to see the PDF you'll receive please use the links above

---

Cells and Tissues
Alana Monet-Telfer

Types of Cells
Cell Groups
What are the Types of Cell Groups?
There are two types of cell groups, therefore, these cell groups are:
Eukaryote Cells: Eukaryote cells contain a nucleus as well as membrane bound organelles
...
Examples of Eukaryote cells are Animal Cells, Plant Cells, Fungi Cells and Protists
Cells
...

Also, this means that the DNA located in these cells are not bound by anything and are known to be less
structured
...

Eukaryote Animal Cell
Organelles and its Functions:
1
...
The nucleus
is seen as a rounded structure; which is encased in membrane and embedded in cytoplasm
...
Chromosomes are located in the nucleus and carry the
gene which makes our DNA
...
The
structures of the chromosomes are elongated and are made from DNA and protein
...
They carry
the genes whose role is to act as an instruction plan for the cell
...

In a protein-coding gene for the first sequence is the promoter
...
On the first
sequence there are coding regions which have the information that is needed to define a sequence of
amino acids that are in the protein
...
The exons
are sections of DNA that are found in the mature transcript
...
This is what the second sequence is like after
it has undergone transcription
...
Introns are the nucleotides in a
gene which are removed by a process called splicing to cause the final sequence product of the gene
...
It is a eukaryote RNA transcript that
has the introns and exons sliced (spliced) and processed for translation in the process of protein
synthesis
...
The bases
are Adenine, Thymine, Cytosine and Guanine
...
In order for a sequence of a base or DNA code to be made purine bases will
always be joined to prymidine bases therefore its sequence goes Adenine-Thymine and CytosineGuanine
...
This is for the DNA to be protected
against viruses and bacteria and also maintains the fertility of the DNA replication
...

1
...
The nucleolus is made from nucleic acids and proteins; therefore, its role is to control the
transcription and congregation of rRNA (ribosomes) which create proteins in protein synthesis
...
Endoplasmic Reticulum: There are two different types of this Reticulum; they are called
smooth and rough
...
The role of the reticulum is to assemble proteins
...

Rough Reticulum
Rough reticulum are covered with millions of ribosomes, therefore, the role of this reticulum is to
assemble lipids and steroids
...

3
...
In this substance
are many different structures
...
Other roles of cytoplasm are to, maintain the
cells shape and store chemicals
...
Centrosome: The Centrosome is also known as Microtubule Organizing Centre (MTOC)
...
The location of this organelle is beside the nucleus
where both organelles are attached together
...


5
...
Each Centriole has
nine clusters of microtubules which control the movement and transport of the cell
...

6
...
The role of the
Golgi is to distribute and store enzymes or hormonal contents of Lysosomes, Peroxisomes and
Secretory vesicles
...


7
...
The role of Lysosomes is to release Hydrolytic enzymes
which are needed for intracellular digestion
...
Another function is autophagy; therefore, this happens when a
catabolic process causes the cell to deteriate its own components; which can be described as
programmed cell death or cell suicide
...

8
...

Its location in the human body is around the Liver and Kidneys
...
Hydrogen Peroxide
is a chemical created by cells, in which the cell will oxidize a chemical toxin, and therefore create
the by-product called Hydrogen Peroxide
...
Therefore, the Peroxisomes will go and break down the Hydrogen
Peroxide to turn it into water and oxygen; which is needed by the body
...
Secretary Vesicles: The secretary vesicles are fused with the Golgi, therefore, its role is to
release or secrete their stored molecules into the organelles
...


10
...
Its role is
to form a shield; however, the cell membrane cannot protect the cell from everything from the
outside
...
Other responsibilities of the cell are to give shape to the entire
cell, connect one cell to another and can serve as an organ for locomotion
...
Mitochondria: The role of mitochondria is to take part in the process of cell respiration
...
Therefore, this helps the cells to carry on doing their bodily functions;
such as creating new tissue, keeping the cells moving, carrying oxygen to the muscles of the body, and
they also remove carbon dioxide and other wastes out from the body
...
In this
type of respiration, three processes take place; Glycolsis, Kerbs cycle and Electron Transport
Phosphorylation
...
The cells located in the organs, tissue, and muscles will respire themselves in order to
create energy to carry out their bodily functions
...

How does Cell Respiration Work?

The chemical energy our cells need comes from the food we eat
...
When an individual eats a piece of food, it goes down the
oesophagus, stomach and the other digestive organs of the body
...
In the process of food oxidisation, most of the food is broken down into
glucose; therefore, this is where the chemical energy needed for the cells, is stored
...
Therefore, once the glucose
has been converted to ATP it’s absorbed by the cells, which gives it energy to carry on its bodily
functions
...


Process in Anaerobic Respiration
Because anaerobic respiration means no oxygen is needed to do it, the only process that takes place is
the Glycolsis Process
...

12
...
ATP is energy which is given to cells so they can do their
functions
...

13
...
The size of the vacuole in an animal cell is small; since it’s not needed that much,
however, in a plant cell the quantity of vacuole is very large and takes up most of the space inside
of a plant cell
...
Pinocytotic Vesicle: The role of this organelle is to store water inside of the cell from the
outside
...
Ribosomes: Ribosome’s are packets of RNA that take part in protein synthesis
...

Protein Synthesis
In the transcription process, the rRNA is synthesized by existing sequences found in DNA
...
After this process, this is where the nucleolus will start its role; therefore, it will surround the rRNA
with protein molecules, hence, two units will form; which are large and small
...
The ribosome will remain in the
cytoplasm where it will become a functioning ribosome
...
Finally, tRNA molecules combine the
specific amino acids together to create a protein
...
Cytoskeleton: The role of cytoskeleton is to hold the structure of the cell as well as help with the
cells movement
...
The nucleus is seen
as a rounded structure; which is encased in membrane and embedded in cytoplasm
...


Nucleolus: Also known as the nucleoli; is a cellular structure which is found in the nucleus of a cell
...

Golgi/Golgi Apparatus/Golgi body: Found on both animal and plant cells; its structure is composed of
five-eight cup shaped membrane sacs which are known as catenae
...
Its other
role is to modify fats and proteins, before sending them out to other locations in the cell
...
The role of the reticulum is to assemble proteins
...

Cell Wall: A cell wall is made from a layer of non living polysaccharide material; which are made from
carbohydrates called cellulose
...

Mitochondria: The role of mitochondria is to take part in the process of cell respiration
...
Turgor pressure is what the vacuole regulated in plant cells to keep the
rigid and straight, however, if for some reason the vacuole can’t support the pressure, it will cause the
plant to wilt and die
...
In this substance are many
different structures
...
Other roles of cytoplasm are to maintain the cells shape and
store chemicals
...

Nucleolus: Also known as the nucleoli; is a cellular structure which is found in the nucleus of a cell
...

Peroxisomes: In a planet cell it takes part in photosynthesis
...
The role of Lysosomes is to release Hydrolytic enzymes which are needed for
intracellular digestion
...

Another function is autophagy; therefore, this happens when a catabolic process causes the cell to
deteriate its own components; which can be described as programmed cell death or cell suicide
...

Cell Membrane: This membrane is a thin layer which is the surface of the actual cell
...
Therefore,
the cell membrane is known as selectively permeable; since it allows certain chemicals to pass in and out

of it
...

Chloroplast: The chloroplast contains chlorophyll which causes all plant cells to have green in their
colour
...
Rough Reticulum: Its role in this cell is to create insulin
...
Ribosomes: Ribosome’s are normally smaller in prokaryote cells
...
Protein synthesis is the transcriptions and translation of
different types of DNA to form proteins
...
Cell Wall: The cell wall is usually chemically complex in prokaryote cells
...

3
...
Other
roles of the capsule are to retain moisture, and help the cell remain to surfaces and nutrients
...
Plasmids: These are genes carrying circular DNA structures that exchange DNA between
bacterial cells
...

5
...

6
...
It’s composed of a double layer of fats
...
Necleoid: The role of the Necleoid is to determine which proteins and enzymes can be
synthesized; hence, it determines what chemical reactions will be played out
...
Pilus: The role of the Pilus is to connect itself to other bacteria
...

9
...

10
...

11
...
Its roles are to protect the cell from the environment
...
Cytosol/ Cytoplasm: Cytoplasm, or Cytosol, has a texture which is similar to sloppy jelly; as well
as being considered a complex substance between a solid and a liquid
...
In this cytoplasm, many chemical reactions take place, therefore, this
is what keeps the cell alive and gives it energy
...

Cells, Tissues and Organs
How do cells create Tissues and Organs?
Cells create tissues and organs through the process called Mitosis
...
These types of cells take place and replicate only in animals and plants for growth and
replacement
...

What is Mitosis?
Mitosis is a cell division process where chromosomes will combine and separate, in this process of
replication, in order to create more cells
...
This separation
creates two daughter cells; with a diploid number of chromosomes
...
This separation will continue with each cell having the diploid
number of chromosomes
...
Prophase1: The homologous chromosomes, centrioles, and organelles are visible in the cell
...

2
...

3
...
In this process,
the chromosomes will move to opposite end of the cells and create two cells; with the haploid
number of chromosomes
...
Telophase1: Cells with haploid number of chromosomes
...

5
...

If this was the reproductive system, the final stage would that four gametes are formed, hence, meaning
these gametes will rather become four separate sperms; or one mature egg
...

What is the Extracellular Matrix?
The Extracellular matrix is a mixture of proteins and polysaccharides which have been made by
endoplasmic reticula and Golgi apparatus
...
This matrix is like glue; which makes the cell bond together
...

Cell Differentiation Process
The process all begins from the fertilisation of an egg to from a Zygote
...
It usually takes four days before the
totipotent cells start to become pluripotent
...
This means that
the cell is created for a certain organ to do one function
...
There are many signals which can cause a cell to go through cell differentiation, for
example, it can be internal signals such as the cell itself causing cell differentiation, or it can be external
signals such as environmental signals or the presence of chemicals in the body; which alters the choice
of which of the cells genes will be turned on or off
...
Once the cell has been altered to do once specific function it is known as a Multipotent cell,
therefore, this means that it will go through cell division and create more cells which are only meant to do
the function for the organ it’s been created for
...


Adult Stem Cells
Adult stem cells can be found in mature adult tissues, for example, muscles, skeletal muscles, bone
marrow brain, liver and the skin
...
For example, if an individual scratches themselves, the stems cells will transform
into platelets and skin tissue in order to repair the cut
...

Adult Stem Cell Types
∑ Totipotent Type: Such Totipotent cells can form from zygote eggs as well as from the division of
the zygote egg
...
These types of stem cells are created from
proliferated cull cultures, which have been left for a long time without differentiating
...
For example, red blood, white blood and platelet cells
...

∑ Unipotent Type: These stem cells normally create muscle; differentiate into all cell types as well
as having the ability to self-renew each other
...

ÿ Epithelial Tissue: This type of tissue is many layers and is located near the intestine, epidermis,
surface of the skin, around the digestive system, and any other type of organ system
...
The properties of
this skin are that they have a minuscule amount of intercellular
substance, and no intercellular spaces
...

The role of this basement membrane is to provide support to the
structure of the skin, absorb food in the small intestine, protect the
under layer tissue from injury, be a sensor for the sensory
systems, secrete hormones, lubricating fluids, and enzymes,
excrete waste products, diffuse gasses, lipids and nutrients,
cleaning the body from dust particles and foreign bodies in the
nose, reduce friction between the blood and the blood walls in the
circulatory system; as well as bind neighbouring structures
together
...
The role and functions of this tissue are to protect
under layer tissue from the environment, be the sensory receptor for the sensory parts of the
body, secrete specific substances, hormones, enzymes, and lubricating fluids in the glands,
absorb nutrients in the intestines, excrete waste products in the kidneys, reabsorb nutrients from
the urea in the kidney tubules, excrete sweat, diffuse gases, liquids and nutrients, cleaning the

nose, throat, and air passages of dust, bacteria, and pathogens, and finally it stops friction in the
circulatory system

Epithelial Skin Types
Simple Epithelial: It’s known as simple because it can be subdivided according to the figure
and function of its cells
...
Therefore, the role of this skin is to determine and name the type of epithelial
skins in the human body
...

The location of this skin is normally around the outer layers of the mouth, heart, blood vessels
and lungs
...
The nucleuses of these types of cells are also cuboids in shape, also
their location in the body is usually in the glands, lining of the kidney tubules, and ducts of the
glands
...

Simple Columnar Epithelium: Cells of this type of tissue occur in many layers
...
The location of this tissue is in the lining of the stomach and
intestines
...
In-between the cells form Goblet
cells, therefore, these cells are located in the epithelial cells of the duodenum
...

Ciliated Columnar Epithelium: These are similar to the simple columnar epithelium;
however, the difference between the two is that this tissue has fine hair products called cilia
...
The area of this tissue is usually in
the nose, uterus, and fallopian tubes
...
The combination
of Columnar cells and cuboidal spherical cells creates specialized gland cells, therefore, the
role of these cells is to secrete and synthesize certain substances, enzymes, hormones, milk
mucus in the mammary glands, sweat, wax, and saliva in the mouth
...
Multicelluar glands can form
from epithelial tissue becoming invaginated; therefore, these glands contain clusters of cells
...
The top cells of this tissue are flat and flaking which are similar to a fish’s scales,
also the cells of some of these tissues do not contain the rough resistant protein called
keratin
...


ÿ

Connective Tissue:
The role of connective tissue in the human body is to support it by
combining all types of tissue together
...
Therefore, by doing this it is also able to create a mechanical framework called the
skeleton, hence it plays an important role in locomotion
...
These cells roles are to secrete enormous amounts of intercellular
ground substance
...
The location of nervous tissue will be of
course in the nervous system, for example, brain, peripheral nerves and spinal cord
...
The
nerves of the body are made from nerve cells which are connected by connective tissue; also, the
nerve is covered by a dense connective tissue called the epineurium
...
There is a lose film of
connective tissue called the endoneurium; therefore, it also encases the nerve fibres
...
With muscular tissue, there are two types of activities
...

∑

Voluntary Movement: Voluntary movements are muscles which can be moved by our
conscious, therefore, meaning that we are in control of our voluntary muscles
...


∑

Involuntary Movement: Involuntary movement is when muscles in the body, such as the heart
and pupils of the eyes, work without out having to control them consciously, therefore, this means
that involuntary muscles are muscles which work by themselves and are out of our control
...
Examples of
organs that move involuntary are is the heart beat, blinking, and the movement of the alimentary
canal
...

Smooth Muscle Tissue: These muscles are elongated thin cell fibres; therefore, the fibres at
the end are pointed with their nucleus being a huge oval shape
...
The cells also have myofibrils which lie corresponding to one another in the long axis
of the cell
...
Also, the location of this type of muscle would be at the walls of hollow organs,
digestive tract, walls of the bladder, uterus, ducts of glands, and blood vessels
...
Skeletal tissue is enclosed by a sheath of connective
called the epimysium; as well as small bundles of elongated, cylinder muscle cells called fibres
...
The role of
this tissue is to create co-ordinate movements of the limbs, jaw, eyeballs, arms, legs, lips, etc
...
The fibres of the cardiac muscle tissue are similar to skeletal muscle tissue, since it has
cross-striations and numerous nuclei
...
Other differences between both cardiac
muscle tissue, and skeletal muscle tissue, is that cardiac muscle tissue are shorter,
the striations are not so visible, the sacrolemma is thinner, there are adjacent fibres,
and the cardiac fibre only has one nucleus
...
The role of cardiac muscle tissue is to control the rhythmic beating of the
heart and pump blood around the body
...

They all are tissues of the human body
...

Skeletal Muscle Tissue and Cardiac Muscle Tissue
In the body some cardiac muscle tissue and skeletal muscle tissue can be found
...

Both Striations are made from the proteins Actins and Myosin
...

Endocrine and Exocrine Gland tissue
Both these glands are made from epithelial tissue
...
However,
connective tissue is used to connect different parts of the body to each other
...
As with connective tissue; they are not tightly packed
together; since they have intercellular substance in between them
...
As for connective tissue, its
role is to structure and support the bones of the body
...

Nervous and Connective Tissue
Nervous tissues have Schwann cells as well as Schwann cell cytoplasm; while connective tissue
does not
...


Muscle Tissue and Nervous Tissue
Nervous tissue has nerves which contain neurons; while music tissue contains myocytes which
are completely different from neurons
...

Nervous tissue can transmit electrical impulses all round the body; while muscles depend on the
contraction muscles, such as the heart to pump oxygen and nutrients around the body
...

Muscle tissue cells usually have oval shaped nucleuses; however, in nerve cells they have one
central nucleus
...

The two different types of tissue are located in different areas of the body
...

Glandular Epithelium and Simple Columnar Epithelium
Glandular Epithelium tissue contains Goblet cells; while the simple columnar tissue does not
...

Skeletal Muscle Tissue and Cardiac Muscle Tissue
Skeletal tissues are attached to the skeletal bones of the body; however, cardiac muscle tissue is
located in the walls of the heart
...

Cardiac muscle tissue striations are not so visible, the sacrolemma is thinner, there are adjacent
fibres, and the cardiac muscle fibres of the tissue only have one nucleus
...

Smooth and Cardiac Muscle Tissue
Smooth tissue has no striations; while cardiac tissue does
...

Cardiac and Skeletal Tissue
Skeletal tissue is voluntary; while cardiac tissue is involuntary
...

Skeletal and Smooth Tissue
Skeletal Tissue is voluntary; while smooth muscle tissue is involuntary
...

Smooth and Skeletal Muscle Tissue
Skeletal muscles are under voluntary control; while smooth muscle is under involuntary control
...

References



---