Download Introduction to the cell

Title: A tour of the cell
Intro: Cells are as basic to biology as atoms are to chemistry. ALL organisms are
comprised of one or more cells. Most cells cannot be seen without magnification,
therefore most peoples understanding of cells and their importance is relatively
new.

An Egg is the largest type of cell
1- The Cell Theory a- The microscope –
1- 1665 Robert Hooke – 1st person to look at cells (cork) – monk. Looked
at non-living things under the microscope.
2- 1700 Anton Van Leeuwenhoek – built his own microscopes – a
merchant (not a scientist). Worked with fabrics and used the
microscopes he made to determine the “thread count.” 1st person to
observe living things under the microscope (took scrapings off his
teeth + saw bacteria under the microscope).
3- Cell theory refers to the idea that cells are the basic unit of structure
in every living thing. Development of this theory during the mid 17th
century was made possible by advances in microscopy. This theory is
one of the foundations of biology. The theory says that new cells are
formed from other existing cells, and that the cell is a fundamental
unit of structure, function and organization in all living organisms.

Cells define our shape and how we work - function (all liver cells look
alike, Kidney cells look alike no matter what animal they are from)
Germans came up with cell theory:
a- Matthias Schleiden – all plants are made of cells
b- Theodore Schwann – all animals are made of cells
c- Rudolf Virchow – all cells come pre-existing cells
4- Cell Theory – Modern interpretation
 Cells contain heredity info in the nucleus
 Proteins for all of life’s functions are produced in the cell
 Genetic material is past from 1 person to the next
5- Overview of animal and plant cells – differences:
a- There are both similarities and differences in plant and animal
cells. Animal cells contain centrioles important for cell division
and small vacuoles to store food and water. Whereas, plant cells
have cells walls (made of cellulose), chloroplasts (photosynthesis)
and one large vacuole to store water. However, in general most of
the organelles found in both plants and animals have the same
function. They are much more alike than different.
6- Two major classes of cells
a- Prokaryotic –
1- lack a nucleus and all other membrane bound organelles
2- much more simple in structure w/DNA concentrated in 1 area
of the cell
3- appear much earlier in the fossil record – arrived earlier in
evolution
TWO GROUPS:
a- The monera are the most common forms of bacteria and
the ones we encounter all the time (causes strep throat)
b- The archaea – ancient bacteria – more simple than the
monera – arrived before the monera
THREE TYPES:
1- halophiles – found in high salt concentrations
( especially in the Dead Sea + Great Salt Lake in Utah)
2- thermophiles – like to live in extreme heat such as in
steam vents from volcanoes and geysers. Different
bacteria thrive in different temperatures.
3 – Methanogens – bacteria that live in the absence of
oxygen ( in methane). Swamp gas reflects this type of
bacteria. They live in our digestive system – large intestine –
they thrive on the methane produced in our digestive system.
They produce vitamin E in our digestive system – goes into our
blood and helps w/clotting.
b- Eukaryotic
1- Eukaryotic cells have a nucleus, which is the largest organelle
in the cells. These types of cells have membrane bound
organelles
2- larger than prokaryotic cells
3- came after prokaryotic cells in evolution
4- Kingdoms that contain eukaryotic cells are Animals, Plants,
Fungus and Protists (1 cell organisms).