Transcript Eukaryotic Cells - Greensburg

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 unicellullar
– Organsims can be multicellular
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” or
“animalcules
• .
• 1670 Robert Hooke
– English scientist
– invented 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 “cells” and they were not hollow like
the cork.
The Cell Theory
• 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 come from like, pre-existing
cells.
Two types of cells exist:
Prokaryotic and
Eukaryotic Cells
Prokaryotic Cells
• Word means “before nucleus”
• Includes all bacteria
– Believed to be the first cells on Earth
Traits:
• Do not have a nucleus
• Do not have membrane bound organelles.
• Genetic material just floats around the
center of the cell.
Eukaryotic Cells
• Word means “contains a true nucleus”
• Examples includes all animals, plants,
fungi, and protist.
• Eukaryotic cells contain a nucleus and
membrane bound organelles.
• Organelles are “tiny organs” within a cell,
each having their own function.
Two types of eukaryotic cells:
Plant-like
Animal-like
Traits common to both
prokaryotic and eukaryotic
cells
-Plasma / cell membranes
-Cytoplasm
-Cell wall
-Genetic material
-Ribosomes
Cell Membrane
The Fluid Mosaic Model is the
model of the structure of the
cell membrane.
Plasma or Cell 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
Food Molecules
Water
Carbon dioxide
Cellular Waste
Excess water
Cytoplasm:
1. -liquid part of the cell
2. -found in all areas between the
nucleus and the cell membrane
3.-made mostly of
water with salts,
amino acids,
nucleotides, etc…
dissolved in it.
Function:
-to suspend and
allow structures
to move about.
Cell Wall:
1.-surrounds cell membrane
-found in plants, fungi, some
bacteria and some protist.
2.-located outside the cell membrane
3.-provides shape and support
4. -has openings so items can pass
through.
5. -made up of cellulose
Genetic Material:
1.-made up of DNA
2.-has instructions for making all cellular proteins.
Prokaryotic Cells:
-Have no nucleus
-DNA is free floating
-DNA is in 1 circular
loop
Eukaryotic Cells:
-DNA contained in a nucleus
-many linear pieces of DNA known as
chromosomes.
Ribosomes:
The cells “workbench”
Job: Makes proteins,
in their linear form, by
assembling amino acids
in the correct order
based on DNA’s code.
Continue on to Bacteria lecture
Continue on to Viruses