Chapter 10.2 - Bacteria Flashcards
What are the traits for a prokaryote
No nucleus
Unicellular
No organelles
Dramatically more complicated than a virus but way less complicated than an animal or plant cell
1-20 micro meters
When were bacteria discovered
In the 17th century
Why were microscopes important
Advances in microscopes revealed the world of prokaryotes
What does the structure of a bacteria have
Cell membrane
Cell wall
Cytoplasm(cytosol)
Nucleoid
Ribosome
What is a cell membrane
The barrier between the organism and their environment
Phospholipid bilayer and proteins
Semipermeable(allows food in and waste out)
What is the cell wall
rigid structure that creates mesh-like layer around the cell
Made of peptidoglycan
What is peptidoglycan
A polymer chain of sugars and amino acids
What is the cytoplasm
A jelly-like substance where cell parts float around
What is the nucleoid
Region where the genetic info for bacteria can be found
What is a ribosome
Protein factories
How do scientists identify cell wall structure
They stain the bacteria cells with various dyes and rinse them with alcohol. The remaining color tells us about the bacteria’s cell wall structure.
What does gram-positive mean
Cell with peptidoglycan
Shows up purple because they retain more of the stain
What does gram-negative mean
Cell wall with little peptidoglycan
Shows up pink because the exterior layer is made up of lipoproteins which doesn’t retain much of the stain
How do antibiotics work
They work by inhibiting the growth of or destroy the bacteria
What are the ways antibiotics target bacteria
Inhibit the cell wall synthesis
Inhibit protein synthesis
Inhibit DNA synthesis
Disrupt the cell membrane functionl
Inhibit metabolism
Why is inhibiting the cell wall synthesis the best choice
Human cells do not have cell walls
What is inhibiting the cell wall synthesis called
Beta-lactans
Bacteria structures parts
Fimbriae
Pilus(plural; pili)
Flagella
Plasmids
What is the fimbriae
Large sticky hairs that help bacteria fasten onto certain substances
What is a pilus
Help facilitate the transfer of DNA from one bacterium to another
What is a flagellum
Tails that spin around to help the cell move
What is the movement called
Taxis
What is chemotaxis
When the movement is in response to a chemical signal
What is a plasmid
Carry just a few genes and are replicated independantly of the chromosomes
What is the definition of horizontal gene transfer
Exchanging genetic materials
What are the three types of gene transfer
Transformation
Transduction
Conjugation
What is transformation
Cell can take in a bit of dna from surrounding area which could become incorperated
Transduction
Genes can be carried by a virus to another cell and incorperated into genome
What is conjugation
Plasmid can be transmitted through pili directly from one bacterum to another
What is binary fission
Similar to mitosis but much simpler
Produces two identical daughter cells
Begin at the origin of replication
- Cell elongates
- DNA replicates
- DNA separates
- Cell pinches in middle and separates
How much does cell division happen
Occurs exponentially and takes less than a couple hours
What limits cell division
Envirmental factors(think about population dynamics)
