Chapter 20.1 Flashcards
What are prokaryotes?
Single-celled organisms that do not have a nucleus, or membrane bound organelles
What are the three shapes of bacteria?
Rod-bacillus, Sphere-coccus, and Spiral-spirillum
What are the two types of prokaryotes?
Archaea and Bacteria
Where are archaea found and what are three types?
Extreme environments, thermoacidophiles, methanogens and halophiles
Are archaea similar to bacteria?
No, some are more similar to eukaryotes
What is the domain of most known prokaryotes?
Bacteria
What are two examples of bacteria?
E. Coli and Clostridium Botulinum
What is the single chromosome of bacterial DNA?
A nucleoid
What is a small, extra loop of bacterial DNA?
Plasmid
What two things make up bacteria other than DNA?
Ribosomes and enzymes
What are the pockets of stored nutrients bacteria form?
Granules
What are the cell membranes of bacteria called?
Lipid bilayers
Do bacteria have cell walls, and if so how many layers are they?
Yes, one to two
What is the cell wall of bacteria made of?
Peptidogylcan
What technique allows biologists to group bacteria into two groups?
Gram staining
What are the factors that determine gram-positive bacteria?
A large amount of peptidoglycan due to their thick cell walls and no outer membrane. They show up as purple in the gram stain which covers up the pink. Their outer layer is arranged as inner cell membrane->thick cell wall.
What are the factors that determine gram-negative bacteria?
A small amount of peptidoglycan due to their thin cell walls and outer membrane layer. They show up as pink in the gram stain. Their outer layer is arranged as inner cell membrane->thin cell wall->outer cell membrane. They are also more resistant to antibiotics.
What are the three types of bacteria based on how they get food and nutrients?
Photoautotrophs, chemoautotrophs, and heterotrophs
What defines a photoautotroph and what are three examples?
They get their energy from sunlight through photosynthesis. Purple sulfur, green sulfur and cyanobacteria.
What do cyanobacteria produce as a byproduct?
Oxygen
What defines a chemoautotroph?
They use molecules that contain sulfur or nitrogen and simple organic molecules to obtain energy.
What is the name for how most bacteria get their food?
Heterotrophs -get their energy from other organisms.
What is the name for a bacteria that gets its food from dead organisms?
Saprobe
What is binary fission, how common is it, and are there mutations?
Mitosis-2 identical new cells, most common, yes
What are the three ways bacteria can form new genetic combinations?
Conjugation, transformation, and transduction
What is conjugation?
When two bacteria share genetic material by sharing a plasmid
What is transformation?
When bacteria take up DNA fragments from their environment
What is transduction?
When genetic material (like a plasmid) is transferred by a virus into a bacteria. They often convey antibiotics resistance.
What are thick-walled structures that help bacteria survive harsh conditions, where are they and how tough are they?
Endospores, surround the DNA and a small bit of cytoplasm, they can survive boiling, radiation, and acid and can be revived after hundreds of years.
