Transcript Red Blood Cells/ Erythrocyte

Red Blood Cells/ Erythrocyte
• This red blood cell carries oxygen from the
lungs to tissues and exchanges it for carbon
dioxide to carry back to the lungs for exhalation.
Unlike most cells, red blood cells have a nucleus
only when they are first formed and lose it as
they mature and pack themselves with red,
oxygen- rich hemoglobin molecules. They must
be pliable and fold so they can enter the tiny
capillaries that extend to the far reaches of the
body. Unsaturated fatty acids in the diet are
important for this pliablity. [Red blood cells are
red, platlets are green]
Amoeba
• The amoeba proteus, a single-celled
organism named for the Greek god
Proteus, has extensions to the cell, known
as pesudopodia, which allow it to move
and capture prey.
Adreanal cell
• In this portaion of an adreanal cell, the
dark oval shapes are lysosomes. A
lysosome is a relatively large vesicle which
contains enzymes involved in breaking
down proteins, polysaccharids, and lipids.
They may contain forty or more different
hydrolytic enzymes.
Green-algae
• The Pandorina, a green-algae protist, is
made up of 32 cells, held together by a
jullylike substance, whose outlines you
can see. Each of these cells can survive
independently of the others. To reproduce,
each cell divides, producing a new cell
inside, and then the parent colony breaks
apart.
Starch molecules
• These starch molecules are important
carbohydrates used in cells for mainly
storage. Chemically, starch is a
polysaccharide, formed by combining
many units of glucose.
Poplar Tree Cell
• A single living cell from the leaf of a
poplar tree.
Escherichia coli
• Shown are cells of Escherichia coli, the
heterotrophic prokaryote that is most
thoroughly studied of all living organisms.
The DNA of the E. coli is the lighter
appearing area in the center of each cell;
this region, which is not enclosed by a
membrane, in known as the nucloid. The
two main cells in the center of the picture
have just finished dividing and have not
yet separated completely.
Chlamydomonas
• An electron micrograph of
Chlamydomonas, a photosynthetic
eukaryotic cell. Some of the organelles
which can be seen from the micrograph
are the nucleus (center), mitochondrion,
and chloroplasts (dark, irregularly shaped).
The large circle near the bottom of the cell
is the organism's food reserve, in the form
of starch granules.
Chlamydomonas
• More cells of the green algae
Chlamydomonas. Note the pair of flagella
with which each cell propels itself through
the water.
Corn plant
• This is an electron micrograph of cells
from the leaf of a corn plant. The nucleus
is the large circle on the right side of the
central cell. Diagonal to the nucleus is a
vacuole, quite characteristic of plant cells.
There are also many mitochondria and
chloroplasts (the dark, membraneenclosed objects).
Embryo of a sea urchin
• Shown is the embryo of a sea urchin at
the two-celled stage of deveopment.
Within each cell is a nucleus that carries
all the genetic information needed for
every cell in the mature sea urchin.
Peroxisome
• Shown here is a peroxisome. The
crystalline material in the center is a
peroxide-producing enzume involved in
the break down of purines.
Cells from the cerebral cortex
• These cells from the cerebral cortex are
the most highly organized structures on
earth. The actions of these cells and the
interconnections among them are
respondible for consciousness,
intellignece, dreams, and memory.
Mitochondria
• Shown here is an electron micrograph of a
mitochondrion. Mitochondria are
surrounded by two membranes; the inner
membrane folds inward to make a series
of shelves called cristae. These cristae
play important roles in the energyreleasing chemical reactions of cellular
respiration that occur in the mitochondria.
Chloroplast
• Shown here is a mature chloroplast. Like
a mitochondrion, it is surrounded by two
membranes. Additionally, it contains an
elaborate internal membrane system
where the light-capturing reactions of
photosynthesis occur.
White blood cell
• In this electron micrograph, a human
white blood cell is trapping bacterial
cells. This type of cell defends the body
against pathogens and other harmful
particles by engulfing foreign objects and
destroying them with the help of enzymes
from the cell's lysosomes.
Pancreas cell
• Shown here is an electron micrograph of a
portion of a cell from the pancreas. The cell has
a large, central nucleus with scattered
chromatin, many mitochondria, large quantities
of rough ER, and many small vesicles. Not only
is the cell itself enclosed by a membrane, but the
nucleus is surrounded by a double membrane
system called the nuclear envelope, and certain
organelles are also membrane-enclosed.