cell theory and prokaryotic cells

a cell is a highly organized compartment

• Bounded by a plasma membrane
• Containing concentrated chemicals in an aqueous solution

The cell theroy states that

• All organisms are made of cells
• All cells come from preexisting cells
• All cells are essentially the same in chemical composition

Implications of the Cell Theory

Because all cells come from preexisting cells
• All individuals in a population of single-celled organisms
are related by common ancestry

All of the cells present in a multicellular organism
• Have descended from preexisting cells
• And are connected by common ancestry

Modern Cell Theory contains 4 statements, in
addition to the original Cell Theory:

◼The cell contains hereditary information(DNA) which is
passed on from cell to cell during cell division.
◼All cells are basically the same in chemical composition
and metabolic activities.
◼All basic chemical & physiological functions are carried out
inside the cells (movement, digestion, etc).
◼Cell activity depends on the activities of sub-cellular
structures within the cell (organelles, nucleus, cell
membrane).

Most cells are small because

larger cells do not function as efficiently

larger cells are

more difficult to control

organisms that are comprised of many small cells are
at

an efficiency advantage over organisms comprised
of few larger cells

what are the two major type of cells ?

Prokaryotic and Eukaryotic

Prokaryotic cells are?

Bacteria and Archaea

Eukaryotic cells are?

Protista, Plants, fungi, aninals

the prokaryotic genome

Sometimes called a nucleoid

• Single, long, very condensed DNA molecule in the form of a
ring

• Attached at one point to the plasma membrane

The Internal Organization of Prokaryotic
Cells/Bacteria

Cell wall (peptidoglycan & lipids)
• Cell membrane (phospholipids & proteins)
• Nucleoid (nucleic acid: DNA)
• Ribosomes (proteins and nucleic acid: RNA)

Domain/ Kingdom: Bacteria

Largest domain of life by sheer number (5 nonillion
[5x1030] bacteria in the world)

All members of this domain are?

single-cell and prokaryotic

Have cell walls that contain?

peptidoglycan

Cell walls are one mechanism by which?

antibiotics work to kill bacteria (penicillin)

Archaea and Eukarya

evolved from bacteria

Domain Archaea

Extreme Environments
1. Sea Ice
2. Deep Sea Vent
3. Sulfuric Spring
4. Salt Lake
5. Soda Lake

Reproduction in Prokaryotic Cells

Asexual

Reproduction by fission

one cell becomes two cells

Archaea were originally found in?

extreme environments

Methanogens

produce methane in anaerobic (no oxygen)
conditions usually at extremely cold temps

Halophiles

live in extreme salt environments

Thermophiles

live in extreme heat >90°C or extreme cold

Acidophiles

Withstand pH 2.0 and lower