Transcript Specialized cells

YOU START LIFE AS A SINGLE
CELL FORMED FROM
THE SPERM AND THE EGG.
From one cell to millions
• The
sperm and egg form your first cell
•This cell will then divide to form two cells
and the two cells divide to become 4
cells, then 8 cells, then 16 cells etc
•This division goes on from the beginning
of your life until the end of your life.
What does a cell look like?
Cell structure
•Cells look different ( there are
approximately 210 different types of cells
found in the human body)
•Each type of cell has a specific job that
they do in the human body
•However, no matter what the type of job
that the cell does in the human body there
will be certain features that all cells will
have.
Cell nucleus
Cell membrane
Cytoplasm
Membrane pores
With a normal light microscope you will probably only be able to see the nucleus,
cell membrane and cytoplasm but there are a lot more really small organelles
In a cell.
Golgi complex
Cytoplasm
What do all these organelles do in a cell?
NUCLEUS: The nucleus contains the D.N.A in the cell and is sometimes called
the control centre of the cell
CELL MEMBRANE: The cell membrane is the outer boundary of the cell which
has small holes or pores in its surface to allow substances to move in and out
the cell.
CYTOPLASM: The cytoplasm is a watery substance which everything in the cell
floats in. As the cytoplasm is mainly water there are a lot of substances
dissolved in the cytoplasm which the cell is able to use.
MITACHONDRIA: The Mitochondria is the powerhouse of the cell. Respiration
occurs in the Mitochondria and releases energy for the cell
RIBOSOMES: Use the information from the D.N.A to make proteins. Ribosomes
can be free or attached to the Endoplasmic Reticulum.
ENDOPLASMIC RETICULUM AND GOLGI COMPLEX: These two organelles
process and package the proteins made by the ribosomes.
DEOXYRIBONUCLEIC ACID
•When the sperm and egg fuse to form the zygote all the
information that makes you unique is contained in this new
cell
•This information is contained in your D.N.A
(deoxyribonucleic acid) and your D.N.A is found in every
one of your cells in your body in the nucleus
•Your D.N.A has the code that tells your body what proteins
to make.
•As everyone's D.N.A is unique you will end up with a
unique combination of proteins which in turn makes you
unique.
Cell nucleus
Chromosome: made up of D.N.A
cell
Double helix
Why do cells look different?
• Cells all have the same basic blueprint but
will have specialised structures that will
allow the cell to carry out different tasks in
the human body.
• All the cells in your body started out from
the original cell created from the sperm and
egg which was not specialised.
•As the number of cells increases they
undergo cell differentiation to become
specialised so that they are able to carry
out a specific job.
SPECIALISED CELLS
RED BLOOD CELLS
OSTEOCYTE
(Erythrocytes)
(bone cells)
SKIN CELLS
HORMONE PRODUCING
CELLS
(E.g.: Pancreatic cells that secrete
(Epithelial cells)
Insulin)
MUSCLE CELLS
(E.g.: smooth , cardiac, striated etc)
LIVER CELLS
(Hepatocyte)
NERVE CELLS
(e.g. Olfactory receptor cell, cold and heat sensitive
Neurons, taste buds, pain sensitive neurons)
PIGMENT CELLS
(E.g. melanocytes produce skin pigment
Retinal pigmented epithelial cells produce eye colour)
WHITE BLOOD CELLS
E.g.: neutrophil, Eosinophil, Helper T cell
Suppressor T cell, Cytotoxic T cell etc
FAT CELLS
(White fat cells, Brown
Cells, Liver Lipocyte)
SECRETORY CELLS
(E.g.: salivary gland cells, mammary gland cell
Sweat gland cells stomach lining cells that secrete
Mucus, ceruminous gland cell in ear)
PHOTORECEPTOR CELLS
(cells in the retina of the eye)
RED BLOOD CELLS
(Erythrocytes)
• Red
blood cells have a biconcave
shape which increases the surface
area of the cell and makes it easier
for the cell to move through narrow
blood vessels
• Red blood cells contain the
pigment Haemoglobin which
carries oxygen
• Mature red blood cells don’t have
a nucleus but they only have a life
span of 28 days.
HUMAN CHEEK CELLS
These cells form the
lining of the cheek
• Cheek cells are a type
of epithelial cell
• Epithelial cells provide
a barrier like the skin.
•
Cell membrane
Nucleus
Cytoplasm
Bone cells (osteocytes)
Fat cells
Cardiac muscle
Nerve cell (neuron)
Striated muscle cells
White blood cells
Image of human skin cell:
. Tissue consists of cells of
similar structure.
Example Muscle tissue
Organs are made up of tissues
of different types
Example: Heart
Organ systems serve the needs
of cells for food, air, and waste
removal
Examples:
Respiratory system
and Digestive
system.