Download Prokaryotes

2.2 Prokaryotes
IB Biology HL 1
Mrs. Peters
Fall 2013
2.2.1 Prokaryote Drawing
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Must be able to
draw and label
all the parts of
an E. coli cell.
2.2 Prokaryotes
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All Bacteria are prokaryotes
– Types: Spirals, rods, and spheres
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Specific Characteristics:
– Single cells (unicellular)
– Nucleoid region with naked DNA (no nucleus)
– No membrane bound organelles
– 70S ribosomes
– Perform all functions of life
– Range in size from .5µm to 1µm
2.2.2 Common Prokaryote Structures
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Cell Wall: rigid structure for
protection, outside cell
membrane
Cell Membrane: controls
transfer of substances in
and out, membrane
enclosing cytoplasm
Cytoplasm: site of
metabolic activity; semifluid that fills interior
70s Ribosomes: site of
protein synthesis
Nucleoid: contains naked
DNA which stores genetic
information (no membrane)
2.2.2 Common Prokaryote Structures
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Pili: attachment structures
on the surface, involved in
reproduction
Flagella: used for
movement, require energy
(tail like threads)
DNA: considered naked (no
proteins associated with it),
located in nucleoid region
Plasmid: small circular
pieces of DNA, separate
from nucleoid DNA
**Capsule: jelly-like outer
coating for protection (not
on all prokaryotes)
(**= not necessary to remember this)
2.2.4 Prokaryote Division
Prokaryotes divide by
binary fission:
1. The single chromosome
replicates
2. The two copies move
apart
3. The cell grows in size
4. The cell membrane
grows inward to divide
the cell into two as new
cell wall is deposited
5. Two daughter cells
result (identical)
Microscope Practice 2:
Prokaryotes
Follow the rules of using microscopes
 Draw bacteria at all three magnifications.
 Remember to fill and label each square
with magnification and what you are
drawing.
 Can draw a mixture of different types of
bacteria or just one type.
 Can use colored pencils or regular pencil
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