intro Flashcards
Who is considered the father of bacteriology and why?
Louis Pasteur, for disproving spontaneous generation and developing aseptic techniques.
What was Antonie van Leeuwenhoek’s contribution to microbiology?
He was the first to accurately observe and describe microorganisms using a microscope.
What was the significance of Koch’s postulates?
They established a systematic method to prove that a specific microbe causes a disease.
What did John Needham’s experiment suggest about spontaneous generation?
He believed microorganisms could arise spontaneously from nutrient broth.
How did Lazzaro Spallanzani challenge spontaneous generation?
He showed that boiling and sealing broth prevented microbial growth, refuting spontaneous generation.
What discovery did Robert Koch make regarding tuberculosis?
He identified Mycobacterium tuberculosis as the causative agent of tuberculosis.
What is the function of the bacterial cell wall?
It provides structural support and protects the bacterium from osmotic pressure.
What is the role of the bacterial capsule?
It prevents desiccation and helps evade the immune response by resisting phagocytosis.
What are pili and their function in bacteria?
Pili are hair-like structures that assist in adhesion to surfaces and DNA exchange in conjugation.
What is the significance of bacterial flagella?
They enable bacterial motility and chemotaxis.
What is the nucleoid in bacteria?
The region where the bacterial chromosome (DNA) is located.
What are plasmids and why are they important?
Small circular DNA molecules that can carry antibiotic resistance genes and be transferred between bacteria.
What is the major structural difference between Gram-positive and Gram-negative bacteria?
Gram-positive bacteria have a thick peptidoglycan layer, while Gram-negative bacteria have a thin layer and an outer membrane.
Which type of bacteria contains teichoic acids in their cell wall?
Gram-positive bacteria.
Which type of bacteria contains lipopolysaccharides (LPS) in their outer membrane?
Gram-negative bacteria.
What is the color of Gram-positive bacteria after Gram staining?
Purple.
What is the color of Gram-negative bacteria after Gram staining?
Pink or red.
Why are Gram-negative bacteria more resistant to antibiotics?
Their outer membrane acts as a barrier to many antibiotics.
What are obligate aerobes?
Bacteria that require oxygen for growth.
What are obligate anaerobes?
Bacteria that cannot survive in the presence of oxygen.
What are facultative anaerobes?
Bacteria that can grow with or without oxygen but prefer oxygen.
What are microaerophiles?
Bacteria that require oxygen but at lower concentrations than in the atmosphere.
What are psychrophiles?
Bacteria that thrive in cold temperatures (below 15°C).
What are thermophiles?
Bacteria that thrive in high temperatures (above 45°C).
