2.2 What's inside bacteria? Flashcards
Name the organelles/molecules within the bacterial cytoplasm
DNA nucleoid Chromosome-packaging proteins Enzymes involved in synthesis of DNA, RNA Regulatory factors Ribosomes Plasmid(s) Enzymes involved in breaking down substrates Inclusion bodies Gas vesicles Magnetosomes Cytoskeletal structures
The nucleoid is composed of _______________ and its function is ___________ within the bacterial cytoplasm.
- DNA, RNA, Protein
- Genetic information storage and gene expression
Choromosome packaging is composed of _______________ and its function is ___________ within the bacterial cytoplasm.
- Protein
- Protection and compaction of genomic DNA
Enzymes involved in synthesis of DNA, RNA are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Protein
- Replication of the genome, transcription
Regulatory factors are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Protein, RNA
- Control of replication, transcription, and translation
Ribosomes are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- RNA, Protein
- Translation (protein synthesis)
Plasmids are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- DNA
- Variable, encode non-chromosomal genes for a variety of functions
Enzymes involved in breaking down substrates are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Proteins
- Energy production, providing anabolic precursors
Inclusion bodies are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Various polymers
- Storage of carbon, phosphate, nitrogen, sulfur
Gas vesicles are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Protein
- Buoyancy
Magnetosomes are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Protein, Lipid, Iron
- Orienting cell during movement
Cytoskeleatal structures are composed of _______________ and their function is ___________ within the bacterial cytoplasm.
- Protein
- Guiding cell wall synthesis, cell division, and possibly partitioning of chromosomes during replication
What are the 3 mechanisms that allow DNA to be compressed in bacteria?
- Use of cations (Mg2+, K+, Na+) to shield negative charges on sugar-phosphate (PO4–) backbone
- Small, positively charged proteins bind to the chromosome to maintain condensed structure
- Topoisomerases modify structure of DNA to enable “supercoiling”
The nucleoid is the ________ (smallest/largest) region in the bacterial cel. ____ (A/No) membrane surrounds the nucleoid
- Largest
- No
What are inclusion bodies?
accumulations of carbon, nitrogen, sulfur, or phosphorous storage compounds
What are sulfur globules?
- inclusion bodies for storing sulfur for energy
elemental sulfur can be used as source of electrons
What is polyhydroxybutyrate (PHB) and what do bacteria use it for?
- inclusion body
- carbon storage compund
- bacteria form them when there’s more carbon around than they can immediately use.
What are gas vesicles?
- microcompartment
- used for buoyanccy control in aquatic environments
Gas vesicles are impermeable to the ________ within the cytoplasm, but not to the ________ that accumulate within them.
- impermeable to the aqueous solution
- permeable to the gases accumulating in cytoplasm
What are carboxysomes?
location of carbon fixation reactions (using RuBisCO enzyme)
The RuBisCO enzyme takes ________ and turns it into _________ during the dark reactions of ___________
The RuBisCO enzyme takes carbon dioxide and turns it into organic carbon during the dark reactions of photosynthesis.
What are magnetosomes?
- Associated w direction finding
- Chains of magnetite found within certain bacteria
Where might magnetosomes be useful for bacteria?
- in an aquatic environment
- can allow bacteria to orient itself downwards and find sediment. can be ideal for bacteria desiring low oxygen conditions
True or false: ribosomes are associated with the DNA.
True: Transcription and translation are co-localized in bacteria
True: Ribosomes and DNA can always be found together in any cell
False: Ribosomes and DNA are never found together in bacterial cells
False: Ribosomes are always localized to the membrane and not to DNA
True: Transcription and translation are co-localized in bacteria
Ribosomes and DNA are found together in bacterial cells!
Specific region in bacterial and archaeal cells that contains the chromosomal DNA:
Nucleoid
What is the intracellular compartment that contains key enzymes involved in the conversion of inorganic carbon into organic matter during photosynthesis?
Carboxysome
What are the 3 microcompartments found in bacteria?
- gas vesicles
- carboxysomes
- magnetosomes
Why is the MreB protein important?
- Determines shape of bacterial cell.
Without MreB, bacteria could only be _______
spherical/ coccoid
What is the purpose if the FtsZ protein?
forms a ring for cell division in bacteria
If a cell does not have the FtsZ protein, the cell becomes _________ and does not form a ___________
- elongated
- division plane
Which of the following is NOT a function associated with the cytoskeleton of bacteria?
Plays a role in cell division
Plays a role in maintaining cell shape
Plays a role in segregating bacterial chromosomes during cell division
Plays a role in the division of the cytoplasm into distinct compartments
Plays a role in the division of the cytoplasm into distinct compartments
What is the role of ParM?
ParM helps separate newly replicated chromosomes.
