Transcript Document

Chapter
7
• Robert Hooke - First
person to see cells, he was
looking at cork and noted
that he saw "a great many
boxes”. (1665)
• Anton van Leeuwenhoek Observed living cells in
pond water, which he
called "animalcules"
(1673)
• Theodore Schwann – zoologist
• observed tissues of animals
• contained cells (1839)
• Mattias Schleiden – botanist
• observed tissues of plants
• contained cells ( 1845)
• Rudolf Virchow
• reported that every living
thing is made of vital units,
known as cells
• predicted that cells come
from other cells. (1850 )
• 1. Every living organism
is made of one or more
cells.
• 2. The cell is the basic
unit of structure and
function. It is the
smallest unit that can
perform life functions.
• 3. All cells arise from
pre-existing cells.
*Why is the Cell Theory
called a Theory and not a
Fact?
ALL cells have these parts
• Ribosomes – make protein for use by
the organism
• Cytoplasm – fluid material
within cell
• DNA – genetic material
• Cytoskeleton – internal framework
of cell
• Cell Membrane – outer boundary,
selectively permeable
• Structure
• Core of DNA/RNA surrounded
by a protein coat
• Reproduction
• Lysogenic or lytic cycle
NOT ALIVE!!
• Disease Causing
• HIV and influenza
• Mimics living cells, but do
not have organelles or selfreplication
True or false:
1. Robert Hooke was the first person to see
cells.__
2. Bacteria cells have a cell membrane.__
3. The Cell Theory was developed by a single
scientist.__
4. Plant cells have cytoplasm.__
5. Cells taken from fungi do not have DNA.__
6. Cells can only come from pre-existing cells.
__
7. It only took five years to develop the Cell
Theory.__
• Cells are classified based on the
presence of a membrane bound nucleus
“-karyote”
• What’s inside the nucleus?
• “pro-”=before
• “eu-”=true
• Prokaryote
• Eukaryote
•
•
•
•
The first cells to inhabit the earth
Simple cells
Bacteria
These cells do NOT have a nucleus, their DNA is circular
and floats in the cytoplasm
Some bacteria have
a tail-like structure
called a flagella, that
helps it to move.
A capsule surrounds
some bacteria and helps
them avoid the body’s
immune system
Bacteria that causes Anthrax.
We talked about Anthrax
before…remember?
• Usually found at center of EUKARYOTIC cell
• Has a nuclear membrane & nuclear pores
• Contains cell’s DNA in one of 2 forms
o chromatin - DNA bound to protein (non-dividing
cell)
o chromosomes - condensed structures seen in dividing
cell
• Also contains an organelle called nucleolus - which
makes the cell’s ribosomes
Mitochondria – this is the cell’s energy center. It
turns food into a chemical energy called ATP
The mitochondria is sometimes called the
“powerhouse” of the cell
Golgi Apparatus – processes, packages and
secretes proteins. It is comparable to a factory
or a post office.
*A vesicle forms with
Golgi to transport
substances outside cell.
Lysosome – Contains digestive enzymes, breaks
things down, "suicide sac”
Endoplasmic Reticulum –
Transport, "intracellular
highway".
-Rough ER contains many
ribosomes & is involved in
protein synthesis
-Smooth ER ribosomes not
found on surface
Cytoskeleton – Helps cell maintain
support & shape and helps with
movement
a. microtubules-hollow structures;
also
Vacuole – storage area for
help build cilia and flagella
water and other substances
b. microfilaments-threadlike
-Paramecium have a
c. centrioles-only in animal cells;
contractile vacuole to get rid
used during cell division (paired)
of extra water
The cell is like a factory. Its
product is protein which goes
to body to serve different
functions.
1. DNA has instructions to
build protein
2. These instructions are sent to
ribosomes
3. The ribosomes build protein
and send it through ER
4. The proteins are delivered
to golgi where they are
completed and “tagged” for
export outside cell
Can you identify
the parts?
• Have additional structures
• CELL WALL – surrounds membrane & provides
additional support
• CHLOROPLASTS – contain green pigment, function
in photosynthesis
• CENTRAL VACUOLE – large water container in center
of cell
Can you identify
the parts?
• Mitochondria and chloroplasts have their own DNA
(separate from the nucleus)
• This supports the ENDOSYMBIOSIS THEORY which states
that eukaryotic cells evolved when prokaryote cells engulfed
or absorbed other cells.
What does
“selectively
permeable
mean?
• Selectively permeable; it regulates what comes
into the cell and what leaves the cell
• It is composed of a double layer of phospholipids
with proteins embedded throughout
• Cilia assemble and disassemble for cytoplasmic movements
that allow cells, such as amoebas, to crawl along surfaces
• Intestines have these as well (called villi)
• Flagella
• Whip-like tails for movement
• Bacteria
• sperm