Download Intro to Prokaryotic and Eukaryotic Cells

Cell Structure and Function
All living organisms are made up of:
cells.
Cells are:
• The basic unit of structure and function of
a living organism.
• Organisms can be either:
– unicellular
• Made up of only one cell
– multicellular
• Made up of many cells working together
History of the cell.
• 1665 Anton van Leevwenhoek:
constructed first simple microscope.
• Viewed pond water and saw tiny
moving structures
• he called “wee little beasties”
• .
• 1670 Robert Hooke
– English scientist and inventor of first
compound light microscope.
– Viewed cork
– Named tiny, hollow units and called them
“cells”.
Approximately 200 years later…
• 1833 Robert Brown
– First to view a nucleus within a cell.
– Scientist now knew that there were structures
within the cell and that cells were not hollow
like the cork.
• 1835 Two German scientist, Theodor
Schwann (Zoologist) and Matthias
Schleiden (Botanist) collectively came to
the conclusion that all plants and all
animals are made up of cells.
• 1855 Rudolf Virchow recorded that “all
cells come from other like and pre-existing
cells.
Cell dividing hyperlink
The Cell Theory
(based on the collective work of these 6 scientist)
• 1. Every living organism is made up of
one or more cells.
• 2. Cells are the basic unit of structure and
function of all living organisms.
• 3. All cells arise from like and pre-existing
cells.
• Skin cells divide to create new cells for the healing process
Two types of cells exist:
Prokaryotic and
Eukaryotic Cells
Prokaryotic Cells
• Word means “before nucleus”
• Includes only and all bacteria
• Believed to be the first cells on Earth
Basic traits:
• Lack a nucleus
• Lacks all membrane bound organelles.
• Genetic material just floats around the
cytoplasm of the cell.
Eukaryotic Cells
• Word means “contains a true nucleus”
• Includes all animals, plants, fungi, and
protist.
Basic traits:
1.Evolved from prokaryotic cells.
2. Contains a nucleus
3. Contains membrane bound organelles.
• Organelles are “tiny organs” within a cell,
each having their own function.
• Because prokaryotic cells do not contain
organelles they are generally much
smaller than eukaryotic cells.
• Since prokaryotic cells do not have
organelles their size must be much smaller
so materials, especially waste, can quickly
exit the cell before it can poison the cell.
• Eukaryotic cells have organelles to contain
the waste until it can exit the cell therefore
the waste is not in danger of poisoning the
cell.
Two types of eukaryotic cells:
Animal like:
Plant-like
Structures common to both
Prokaryotic and
Eukaryotic Cells
(or in other words ALL cells)
Cell Membrane
Cell Membrane: (sometimes referred to as
plasma membrane)
Function:
1. Outer boundary of the cell
-separates one cell from another
2. Acts as a “gatekeeper”
-regulates what is allowed to enter
or leave the cell.
Oxygen, amino
acids, Water
Carbon dioxide
Cellular Waste
Excess water
3. Aids in protection and support.
-keeps out bad things
-provides some shape
Cytoplasm:
1. -liquid part of the cell
2. –fills the internal volume of the cell
3.-made mostly of
water with salts,
amino acids,
glucose, nucleotides,
O2 etc… dissolved in
it.
Function:
-to suspend and
allow items and
structures to move
about in the cell.
Cytoplasm
hyperlink
What type
of cell is
this?
Plant cell
Eukaryotic
or
Prokaryotic?
Eukaryotic
Bacteria Cell
Prokaryotic or Eukaryotic?
Prokaryotic
Cell Wall:
1.-surrounds the cell membrane
-found in plants, fungi,
bacteria and some protist.
2.-located outside the cell membrane
3.-provides shape and support
Cell membrane
Cell wall
4. -has openings so items can pass
through.
5. -made up of cellulose/a polysaccharide
humans can not digest.
Cell wall of a bacteria cell
Genetic Material:
1.-made up of DNA
2.-has instructions for making all cellular proteins
these proteins go on to determine our traits.
In Eukaryotic Cells:
-DNA contained in a nucleus
-each linear pieces of DNA known as
chromosomes.
-Humans have 46 chromosomes/cells
-23 from your mom
-23 from your dad
Nucleus:
1.-Known as the brain of cell
2.-It is the cells control center
3.-Contains the DNA
4.-Outside of nucleus is surrounded by another
membrane
5.-contains pores for items to move in and out.
Nuclear Envelope or membrane:
-outside of nucleus, contains with pores
Nucleolus:
-circular structure within nucleus
-makes the ribosomes
Nucleoplasm:
-cytoplasm inside
the nucleus
Genetic Material in Bacteria
Bacteria are classified as being………
Prokaryotes
Which means ……………
They do not have a nucleus
The genetic material/DNA of a
bacteria cell is just free floating
around in the cytoplasm of the
cell.
Genetic
material/DNA
Ribosomes
The cells “workbench”
Job: Makes proteins, in their linear form, by
assembling amino acids in the correct order based
on DNA’s code.
-Ribosomes are made up of RNA and proteins.
-Two types:
1. -Found attached to the endoplasmic reticulum
Prokaryotic
Eukaryotic
or
-Free floating in the cytoplasm