p.5
Molecular Basis of Heredity and DNA
What are the two types of regions found in rRNA?
Conserved and variable regions.
p.3
Molecular Basis of Heredity and DNA
What was the key experiment that initiated the hunt for the molecular basis of heredity?
The experiment by British bacteriologist Frederick Griffith.
p.5
Bacterial Cell Structure and Function
What does the cell envelope consist of?
A series of layered structures that surround the cytoplasm.
p.8
Transporting Nutrients into the Cell
What is the function of lac permease?
It is a symporter that cotransports solute and a proton in the same direction.
p.6
Bacterial Cell Structure and Function
What does the cytoplasmic membrane surround?
The cytoplasm, which is a mixture of macromolecules and small molecules inside the cell.
p.6
Bacterial Cell Structure and Function
What are integral proteins?
Proteins that are embedded within the membrane.
p.6
Bacterial Cell Structure and Function
How does the cytoplasmic membrane protect the cell?
It protects the cell from mechanical stress and can help the cell attach to surfaces.
p.6
Bacterial Cell Structure and Function
Do all cells have a cell wall?
No, not all cells have a cell wall, but all have a cell membrane.
p.3
Evolutionary Relationships and rRNA
Who proposed that molecular sequences could be used to reconstruct evolutionary relationships?
Emile Zuckerkandl and Linus Pauling.
p.8
Transporting Nutrients into the Cell
What are the three components of an ABC transporter?
1. Binding protein 2. Transmembrane protein channel 3. ATP hydrolyzing protein.
p.10
Bacterial Cell Structure and Function
How thick can the peptidoglycan layer be in gram-positive bacteria?
15 or more layers thick (20-35 nm).
p.8
Transporting Nutrients into the Cell
What is the role of the sodium-proton antiporter?
It transports solute and a proton in opposite directions.
p.5
Germ Theory of Disease
What was the conclusion of John Needham's experiment?
It seemed to support the idea of spontaneous generation because microorganisms appeared after boiling.
What did Ferdinand Cohn discover?
The existence of heat-resistant bacterial endospores.
p.11
Differences Between Bacterial and Archaeal Cell Walls
What is the structural difference between peptidoglycan and pseudomurein?
Pseudomurein contains NAT instead of NAM.
p.9
Bacterial Cell Structure and Function
How do bacterial cell walls protect against osmotic lysis?
By maintaining cell shape and rigidity.
p.1
Pasteur's Swan-Neck Flasks Experiment
What was the significance of Pasteur's swan-neck flasks experiment?
It provided the final blow to the theory of spontaneous generation.
p.3
Evolutionary Relationships and rRNA
What is the significance of ribosomal RNA (rRNA) genes in understanding evolution?
They revolutionized the understanding of microbial evolution and allowed for the construction of the first universal tree of life.
p.10
Bacterial Cell Structure and Function
What is the structure of peptidoglycan in bacterial cell walls?
Strands run parallel around the circumference of the cell.
p.3
Molecular Basis of Heredity and DNA
What does the statement by Kluyver and Monod imply about the study of bacteria?
It emphasizes the importance of working with bacteria to understand fundamental biological principles.
p.8
Transporting Nutrients into the Cell
Why is phosphoenolpyruvate (PEP) not the main energy currency of the cell?
PEP has an additional phosphate group and is converted to pyruvate.
p.4
Evolutionary Relationships and rRNA
What significant realization did Carl Woese have in the 1970s?
The sequence of ribosomal RNA (rRNA) could be used to infer evolutionary relationships.
p.1
Vaccine Development and Attenuation
What is attenuation in the context of vaccines?
Incubation of cultures for long intervals causes pathogens to lose their ability to cause disease.
p.10
Bacterial Cell Structure and Function
What is the significance of targeting the bacterial cell wall with antibiotics?
Antibiotics target the cell wall and peptidoglycan layer of bacteria cells, not human cells.
p.7
Bacterial Cell Structure and Function
What is the difference between low-affinity and high-affinity transporters?
Low-affinity transporters function when nutrients are abundant, while high-affinity transporters are reliable in nutrient-poor environments.
p.6
Bacterial Cell Structure and Function
What are transmembrane proteins?
A type of integral membrane protein that extends completely across the membrane.
p.5
Microbial Diversity and Enrichment Culture Techniques
What is the significance of analyzing the sequence of target genes?
It reveals the extent of microbial diversity.
p.9
Bacterial Cell Structure and Function
What happens to Gram-negative bacteria during the decolorization step of Gram staining?
Ethanol creates temporary holes in the outer membrane, allowing the crystal violet-iodine complex to escape.
p.6
Bacterial Cell Structure and Function
What is the significance of the cytoplasmic membrane's physical weakness?
It is an ideal structure for its major cellular function of selective permeability.
p.3
Bacterial Cell Structure and Function
What is the role of ribosomal RNAs in cells?
They are components of the ribosome, which is used by all cells to make proteins.
p.4
Evolutionary Relationships and rRNA
What does the universal tree of life based on rRNA gene sequences depict?
The evolutionary history of all cells and reveals the three domains.
p.2
Antimicrobial Compound Discovery
What did Alexander Fleming discover?
Penicillin, the 'miracle drug' from Penicillium.
p.11
Bacterial Cell Structure and Function
How does lysozyme affect peptidoglycan?
It cleaves the glycosidic bond between N-acetylglucosamine and N-acetylmuramic acid.
p.11
Bacterial Cell Structure and Function
What role do bacterial cell walls play in microbial physiology?
They contribute to structural integrity, regulation of cell growth, cation binding, virulence, antimicrobial resistance, and biofilm formation.
p.9
Bacterial Cell Structure and Function
What is the difference in cell wall thickness between Gram-positive and Gram-negative bacteria?
Gram-positive cell walls are thicker than those of Gram-negative bacteria.
p.8
Transporting Nutrients into the Cell
What is group translocation?
Chemical modification of a transported substance driven by phosphoenolpyruvate.
p.3
Molecular Basis of Heredity and DNA
What did the Avery-MacLeod-McCarty experiment demonstrate?
That the 'transforming principle' was DNA.
What did Koch infer about microbial colonies?
Each colony arose from a single bacterial cell.
p.1
Germ Theory of Disease
What did Girolamo Fracastoro theorize about diseases?
Diseases were caused by invisible living creatures.
p.7
Bacterial Cell Structure and Function
What is the role of transport proteins in the cytoplasmic membrane?
They accumulate solutes against the concentration gradient and display high sensitivity and specificity.
p.2
Microbial Diversity and Enrichment Culture Techniques
What is the significance of the enrichment culture technique?
It selectively encourages the growth of specific microorganisms.
p.5
Evolutionary Relationships and rRNA
What does the root of the universal tree represent?
A point in time when all extant life on Earth shared a common ancestor, the last universal common ancestor (LUCA).
p.8
Transporting Nutrients into the Cell
What is the first step in glycolysis?
Phosphorylation of glucose.
p.10
Bacterial Cell Structure and Function
What unique component is present only in NAM?
Diaminopimelic acid (DAP).
p.9
Bacterial Cell Structure and Function
What is unique about peptidoglycan?
It is unique to Bacteria and not found in Archaea or Eukarya.
p.4
Evolutionary Relationships and rRNA
Why are genes encoding rRNAs considered excellent candidates for phylogenetic analysis?
They are present in all cells, functionally constant, highly conserved, and of adequate length.
p.3
Molecular Basis of Heredity and DNA
What did Jacques Monod reformulate from Kluyver's statement?
“What is true for E. coli is also true for the elephant.”
p.10
Bacterial Cell Structure and Function
How many layers of peptidoglycan are typically found in gram-negative bacteria?
2-3 layers (2-7 nm thick).
p.7
Bacterial Cell Structure and Function
What is the role of the cytoplasmic membrane in energy conservation?
It is the site of generation and dissipation of the proton motive force.
p.2
Microbial Diversity and Enrichment Culture Techniques
What is chemolithotrophy?
A metabolic process where energy for growth is produced using only inorganic chemical compounds.
p.8
Transporting Nutrients into the Cell
What is active transport in cells?
The process where cells accumulate solutes against the concentration gradient.
p.1
Vaccine Development and Attenuation
What diseases did Pasteur develop vaccines for?
Anthrax, fowl cholera, and rabies.
Who developed the Petri dish and when?
Richard Petri developed the Petri dish in 1887.
p.4
Evolutionary Relationships and rRNA
What is the significance of the 16s rRNA gene?
It is of adequate length to provide a deep view of evolutionary relationships.
p.2
Vaccine Development and Attenuation
What vaccination procedure did Edward Jenner use?
He used pus from cowpox blisters to inoculate individuals against smallpox.
p.7
Bacterial Cell Structure and Function
What are the polar head groups in archaeal lipids made of?
They can be sugars, ethanolamine, or a variety of other molecules.
p.6
Bacterial Cell Structure and Function
What are peripheral proteins?
Proteins that are attached to the membrane but not embedded.
p.5
Molecular Basis of Heredity and DNA
What is the function of conserved regions in rRNA?
They are used for protein synthesis.
p.9
Bacterial Cell Structure and Function
What role does iodine play in the Gram staining process?
Iodine acts as a mordant, forming a complex with crystal violet.
p.8
Transporting Nutrients into the Cell
What happens to ATP when it is hydrolyzed?
It breaks down into ADP and inorganic phosphate, releasing energy.
p.7
Bacterial Cell Structure and Function
What is the significance of the cytoplasmic membrane in Archaea?
It provides strength and acts as a permeability barrier, preventing leakage and facilitating nutrient transport.
p.1
Antiseptic Techniques and Asepsis
What was the impact of Ignaz Semmelweis's handwashing policy?
Mortality rate in obstetrical wards dropped from 18% to 2.4%.
p.7
Bacterial Cell Structure and Function
What is crenarchaeol?
A type of monolayer lipid found in some Archaea, which is stronger compared to diglycerol.
p.6
Bacterial Cell Structure and Function
What is the fluid mosaic model?
A model describing the structure of the cytoplasmic membrane, highlighting its fluidity and the presence of proteins.
p.3
Molecular Basis of Heredity and DNA
What did Albert Jan Kluyver promote in the study of biochemistry?
The study of comparative biochemistry to identify the unifying features of all cells.
What is the first postulate of Koch's postulates?
The suspected pathogen must be grown in pure culture.
p.5
Bacterial Cell Structure and Function
What are the functions of the cell envelope?
It governs transport of nutrients and wastes, is the site of energy conservation, and governs cell shape.
What significant award did Koch receive in 1905?
The Nobel Prize for Physiology or Medicine.
p.2
Vaccine Development and Attenuation
What is the purpose of attenuation in vaccine development?
To weaken the causative agent using a natural host.
What is Koch's postulate?
Causative agents must be present in individuals with the disease and absent in healthy individuals.
p.11
Differences Between Bacterial and Archaeal Cell Walls
Why is the Gram stain reaction not useful for Archaea?
Because most Archaea lack a polysaccharide-containing cell wall.
p.1
Germ Theory of Disease
What did John Tyndall demonstrate about dust?
Dust carries microorganisms.
p.4
Evolutionary Relationships and rRNA
What classification scheme did Robert Whittaker propose in 1969?
A five-kingdom classification scheme.
p.1
Vaccine Development and Attenuation
Who was the first human to receive the rabies vaccine?
Joseph Meister, a young French boy.
p.10
Bacterial Cell Structure and Function
What is the role of teichoic acids in gram-positive bacteria?
They are composed of glycerol phosphate or ribitol phosphate and are covalently linked to the peptidoglycan layer.
p.2
Antimicrobial Compound Discovery
What compound did Paul Ehrlich develop to treat syphilis?
Salvarsan, the 606th compound.
p.11
Bacterial Cell Structure and Function
How do antibiotics like penicillin affect bacterial cell walls?
They interfere with cell wall synthesis and prevent the formation of peptide cross-links.
p.7
Bacterial Cell Structure and Function
What is the primary structural difference between eukaryotic and prokaryotic membranes?
Eukaryotic membranes typically have a bilayer structure, while some prokaryotic membranes, particularly in Archaea, can have a monolayer structure.
p.5
Microbial Diversity and Enrichment Culture Techniques
How many domains may organisms be classified into?
They may be classified into three domains: Eukarya, Archaea, and Bacteria.
p.1
Antiseptic Techniques and Asepsis
What did Joseph Lister contribute to surgery?
He used phenol in surgical dressings and heat-sterilized instruments, providing evidence that microorganisms cause disease.
p.11
Bacterial Cell Structure and Function
What type of bond does lysozyme target in peptidoglycan?
Beta 1,4 glycosidic bond.
p.1
Germ Theory of Disease
What did Agostino Bassi show regarding silkworms?
A disease of silkworms was caused by a fungus.
p.11
Differences Between Bacterial and Archaeal Cell Walls
What is the function of the S-layer in Archaea?
It acts as a rigid protein shell to prevent osmotic lysis.
