Chapter 3: Cell Structure: Internal Structures Flashcards
What is the cytoplasm?
The substance inside the plasma membrane
What is the cytoplasm composed of? (5)
- About 80% water
- contains most of the “stuff” needed for life
- sugars, AA, nucleotides, etc.
- enzymes
- some functional structures
What does the nucleoid contain? (3)
- bacterial chromosome (DNA)
- may also contain plasmids
- not surrounded by a nuclear membrane
What is a bacterial Chromosome (DNA)?
- all the genetic information required for cell’s structure and functions
What are plasmids?
- smaller, double stranded DNA molecules
- contain non-essential genes
Ex. Genes for antibiotic resistance
How do bacteria replicate?
Binary fission
How will coiled DNA migrate in gel electrophoresis?
Will not migrate, only linear will migrate
What are ribosomes?
- site of protein synthesis
What are ribosomes made of?
Protein and rRNA
What are the two subunits of bacterial ribosomes, and what do they form? (3)
- 30S subunit
- 50S subunit
- they form the complete 70S ribosome
How do ribosomes of bacteria differ from eukaryotic robosomes?
- Eukaryotes have 80S ribosomes
What targets bacterial ribosomes? (3)
- several antibiotics
- streptomycin, erythromycin
- prevent the bacteria from making new proteins
What are storage granules (inclusion bodies) ?
- usually deposits or granules of nutrients, stored for later use
What are some examples of storage granules (inclusion bodies)? (5)
- sulfur granules
- polysaccharides (glycogen)
- lipid inclusions
- enzymes
- magnetite
What is the function of storage granules?
- a variety of inclusion bodies occur in different bacterial species
- can serve as a basis for identification
What type of bacteria form endospores?
- some Gram positive bacteria
What is the function of endospores? (3)
- special resting structure that allows bacteria to enter dormant state
- remains dormant until good growth conditions occur
- thus can form a new population
How are endospores extremely durable?
- resists heat, desiccation, chemicals, radiation, etc.
- some endospores can survive in boiling water for hours
Give 2 examples of endospores
- bacillus anthracis - causes anthrax
- clostridium botulinum - causes the food borne illness botulism (done by dented cans too)
