Transcript Cell Theory - Downtown Magnets High School

Cells: Prokaryotes
Biology Standard 1 a and c
HIStory
• Anton Van Leeuwenhoek: Dutch
inventor of microscope; 17th cent.
HIS…tory
• Robert Hooke: Englishman termed the
name “cell” after looking at dead cork
under a microscope
Cell Theory
1. All living things are
composed of cells.
2. Cells are basic units of
structure and function in
living things.
3. All cells come from
preexisting cells.
3 Types of Cells
•
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•
•
Prokaryotes, eukaryotes, or viruses
Prokaryotes: Bacteria
Eukaryotes: Plants and Animals
Viruses: Non Living, need a host
Viruses
• Considered
not Living 
needs a host
cell to survive.
• Ex:
bacteriophage
virus
Prokaryotes
• Earliest cells
• Small!
• No nucleus (home for DNA)
•Discuss a sickness
you have had (that
has been caused by
a bacteria).
•What are the
symptoms and how
was it cured?
Have Cell Walls
Cell Wall
• Surrounds plasma membrane
• Serves as protection, made of
peptidoglycan
Have Plasma Membranes
• Surrounds cell; regulates
materials in and out of cell
DNA
• Is housed in a region called the nucleoid
DNA
• Is usually
small and
circular
• Has
plasmids:
extra DNA, No
chromosomes
Have Ribosomes
• Sites where
proteins are made
• Float in cytosol
(fluid in cell)
Can Have
Flagellum for
Movement
Types of Bacteria
Case Study: Salmonella
Poisoning
• Milk, eggs, water, meat, veggies and
fruits exposed to human feces, farm
animals
• Symptoms: fever, nausea, dehydration,
diarrhea
• Last 4-7 days, treated with antibiotics
and rehydration
Case Study: Salmonella
Poisoning
• Prevention: Cook your Meat!
• Wash hands after touching farm
animals/reptiles
• Wash fruits and veggies
• Don’t eat raw eggs