Microbiology Exam 1 pt.1

Where is most ATP made in a Gram-negative bacterium?

Plasma membrane (via oxidative phosphorylation)

Do Gram-negative bacteria have mitochondria?

No — they use the plasma membrane for ATP production.

What is the clinical relevance of the human microbiome?

Helps prevent disease, competes with pathogens, and supports immune system.

Why can antibiotics cause side effects?

They kill good bacteria in the microbiome along with pathogens.

Do antifungals kill bacteria?

No — they target fungi, not bacteria

What happens if pH suddenly drops in exponential phase?

Growth slows → exponential phase becomes shorter.

What happens to glucose in glycolysis?

It is oxidized to pyruvate → pyruvate can go to fermentation or Krebs cycle.

Do prokaryotes have nuclei?

No — they have a nucleoid (free-floating DNA).

Where is most ATP made in eukaryotes?

In the mitochondria (ETC/oxidative phosphorylation)

What is disinfection?

Killing/removing some microorganisms (not all).

Are most human pathogens mesophiles?

Yes — they grow best at body temperature (37°C).

Are all cocci Gram-positive?

No — some are Gram-negative.

When do humans get their microbiome?

At birth and during life through environmental exposure.

What do eukaryotes use for asexual reproduction?

Mitosis (not binary fission).

Where is ATP produced in Gram-positive bacteria?

Plasma membrane (not outer membrane — they have no outer membrane)

Q: What protects endospores from disinfectants?

Multiple protective layers (resistant structure).

What is a bacterial capsule?

Organized glycocalyx made of polysaccharides that helps attach and evade immune system.

What is a biofilm?

Community of bacteria attached to a surface, protected by matrix → harder to kill.

What do all living microorganisms have?

Plasma membrane + ribosomes.

What does binary fission produce?

2 genetically identical prokaryotic cells.

What makes more ATP — fermentation or aerobic respiration?

Aerobic respiration (much more ATP).

Where is pyruvate converted to acetyl-CoA?

Pyruvate oxidation step (before Krebs).

What do all catabolic reactions create?

ATP (used by anabolism).

Which prokaryote classification does Methanobrevibacter smithii belong to?

Archaea (prokaryote, no membrane-bound organelles, unicellular).

What does VBNC mean?

Viable but non-culturable (alive but won’t grow on lab media).

Is the inner mitochondrial membrane a good antibiotic target?

No — humans need it for ATP production.

Does peptidoglycan synthesis use ATP?

Yes — it’s an anabolic process.

Which microorganisms have peptidoglycan?

Only bacteria (not fungi or protozoa).

Where is ATP highest in a fungal cell?

In the mitochondria.

What does anabolic mean?

Building big molecules from small ones (uses ATP)

Is anabolism energy-using or energy-making?

Energy-using (uses ATP)

Give an example of an anabolic process.

Protein synthesis (making proteins from amino acids)

What does aerobic mean?

Requires oxygen to make energy (ATP)

Where does aerobic respiration happen in bacteria?

Plasma membrane (ETC)

Where does aerobic respiration happen in eukaryotes?

Mitochondria (ETC)

Which one makes ATP — anabolic or aerobic respiration?

Aerobic respiration (makes a lot of ATP)

Which one uses ATP — anabolic or aerobic respiration?

Anabolic (needs ATP to build molecules)