Download Tour Of the cell

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All cells have
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Plasma membrane – an
outer boundary
 Covers the cell’s surface
 Acts as a barrier
between the inside and
the outside
 All materials enter
through the plasma
membrane
 Made of phospholipids,
proteins and cholesterol.
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All cells have
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Cytoplasm
 Within the plasma
membrane
 Includes fluid, cytoskeleton,
and organelles
 Cytosol is the liquid
 Made up of water and
proteins
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All Cells Have
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DNA
 Controls what goes on in
the cell
 Tells the cell what
proteins to make
 Copies itself for
reproduction
 Made of Nucleotides
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There are two basic types of cells
Prokaryotes
Organisms that are unicellular
 Do not have a membrane bound nucleus
 Do not have membrane bound organelles
 Even though they do not have a nucleus they still
have DNA in the center region called the nucleoid.
 Bacteria and Archaea
 May be the first life forms
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Eukaryotes
Organisms made up of one or more cells that have a
nucleus.
 Have many membrane bound organelles
 Organelles carry out different functions
 Much larger than prokaryotes
 Include Animal Cells, Plant Cells, Fungi, Protists
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Phospholipid Bilayer
Two layers of phospholipids
 Phospholipids have a hydrophilic head and a
hydrophobic tail
 Makes the membrane fluid
 Makes the membrane semi permeable
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Cholesterol
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a lipid that makes the membrane firm
Prevents the membrane from freezing at low
temperatures
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Membrane Proteins
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Glycoproteins – identifies other cells receives signals
Integral Proteins – span from one side of he
membrane to the other, transport materials into and
out of the cell.
Peripheral proteins – enzymes that speed up
(catalyze) reactions in the cell
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Most functions are
controlled by the
nucleus
Filled with nucleoplasm
Contains genetic
information which
codes the structure and
function of the organ
Made of DNA &
proteins
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The nucleus is the site
where DNA is
transcribed into RNA
which moves through
nuclear pores to the
cytoplasm
The nuclear envelope
surrounds the nucleus.
Made of phospholipids
and proteins
Nuclear Pore
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Most nuclei contain one
or more denser/darker
areas
Is the site where
ribosomes are made
Ribosomes make
proteins in the cell
Made of dense DNA
Nucleolus
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Tiny organelles that
transfer energy from
organic molecules (like
sugar) to ATP
ATP is the energy that the
cell uses to function.
Has its own DNA
Can reproduce by fission
like bacteria.
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Cells that are very active like muscle cells
have a lot of mitochondria
Cells that are not active like fat storage cells
do not have a lot of mitochondria.
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Outer membrane –
smooth and completely
permeable to nutrient
molecules, ions, ATP
and ADP molecules.
Inner membrane – has
many folds and
proteins that aid in the
production of ATP, the
energy rich molecules.
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Cristae – the infolds of
the inner membrane
Matrix – the space in
between the folds. Has
a mixture of enzymes
that are important for
the synthesis of ATP
molecules, special
mitochondrial
ribosomes, and DNA
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Due to their independence from the nuclear
DNA and similarities with bacteria, it is
believed that mitochondria have originated
from bacteria by endosymbiosis.
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Ribosomes are the sites
of protein synthesis.
Occur in both
prokaryotes and
eukaryotes.
Are found floating
around the cytoplasm
or attached to the
endoplasmic reticulum
and in the
mitochondria.
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Tiny organelles composed of both proteins and
RNA
Each subunit consists of one or two very large
RNA molecules (known as ribosomal RNA)
and several smaller protein molecules.
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Abbreviated ER is the system of membranous
tubes that run throughout the cell from the
nucleus to the cell membrane
Functions as an intercellular highway, a path
through which molecules move from one part
of the cell to another.
Two types
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Rough ER
Smooth ER
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Covered with ribosomes
Produces phospholipids and
proteins
Proteins are made on the
surface by the ribosomes and
then imported into the cell or
the cell membrane by the rough
ER.
There is a lot of rough ER in
cells that produce lots of
proteins like the pancreas and
white blood cells.
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Does not have ribosomes on the surface
Most cells have a small amount of smooth ER
Builds lipids like cholesterol, testosterone,
estrogen,
Releases calcium
Abundant in liver cells and the kidney cells
The more alcohol & drug abuse, the more
smooth ER.
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Also called Golgi Body or just Golgi
Flattened membranous sacs
Found in all eukaryotic cells
Functions as a packaging and distribution
center
The sacs nearest the nucleus receive vesicles
from the ER containing newly made proteins
and lipids.
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As the vesicles move
along inside of the
Golgi, the contents are
modified, they get
address label to be sent
somewhere in the cell.
The modified proteins
and lipids leave out of
the other side of the
golgi.
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Small sacs that move
substances through the cell
and to the membrane to be
released from the cell.
Lysosomes – contain digestive
enzymes that digest bacteria
and dead cell parts.
Peroxisomes – neutralize free
radicals like hydrogen
peroxide.
Glyoxysomes – break down
stored fats in seeds
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Endosomes – engulf materials to take to the
lysosomes to digest
Food Vacuoles – store nutrients for the cell
Contractile vacuoles – expel excess water from
the cell.
Contractile Vacuoles
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Hairlike organelles that extend from the
surface of cells.
Found on many eukaryotic cells.
Cilia are mostly found on animal cells
They assist in movement .
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Short and hairlike
Found in thousands on the surface of cells.
Help unicellular organisms move through
water to find food.
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Also found on cells lining the respiratory tract.
Trap particles and debris from the air we
inhale.
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Longer and less numerous than cilia
A cell could have one flagella (sperm) or many.
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Structure are the same for cilia and flagella.
They are composed of 9 pairs of microtubules
arranged around a central pair.
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Only found in plant
cells and fungi.
Rigid and made of
cellulose in plants
and chitin in fungi
Helps to support and
protect the cell
membrane.
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Only found in plant cells
Trap sunlight to create sugar/ food for the
plant cell.
Flattened membranes called thylakoids
enclosed in a membrane
Contain a green pigment called chlorophyll.
Give plants their color
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Are like mitochondria in that they contain their
own DNA and ribosomes.
They are surrounded by a double membrane.
They can reproduce themselves inside of the
plant cell.
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The shapes of cells vary.
Some, such as nerve cells are being longer than
they are wide.
Parenchyma (a common type of plant cell) and
Red blood cells being equal on all sides.
Some cells are encased in a rigid wall, which
confines their shape.
Some have a flexible cell membrane (and no
rigid cell wall).
Amoeba
Red Blood Cells
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The size of cells is also related to their
functions.
Eggs are very large, often being the largest cells
an organism produces.
Cells range in size from small bacteria to large,
unfertilized eggs laid by birds and dinosaurs.