MIMG 101 Midterm 1 (Lec 6-8) Test
Questions All Answered Correctly
2026 Updated.
Know the types of equal and unequal cell division - Answer Equal: binary fission
Unequal: budding
Budding division - Answer - a new cell emerges and buds off from a mother cell (daughter cell
is genetically identical but different in size/function from mother cell)
- some budding bacteria have cytoplasmic extensions
- in multiple fission, one hyphae has multiple locations of new cell growth along its length
Describe the steps of binary fission (bacterial DNA replication, molecular mechanism of septum
formation, steps of new peptidoglycan synthesis) - Answer - most bacteria grow asexually --
binary fission
- copies its chromosomes
- elongates
- splits into 2 daughter bacteria w/ identical genetic make up
Bacterial DNA Replication - Answer - semiconservative: every new DNA strand has one new
and one old strand
- bi-directional: circular DNA has two replication forks (creates a "theta" structure)
- bacteria initiate 2nd replication fork before 1st one is completed --> bacteria can replicate very
fast!
(when first replication is completes and new cells are made, DNA is already being replicated in
the daughter cells for the next cell divison)
FtsZ - Answer - FtsZ is a tubulin-like protein
- Division starts with FtsZ assembling to form a ring around the center of the cell
- FtsZ then interacts with ZipA to anchor the ring to the cytoplasmic membrane
- FtsA (actin-like protein, membrane anchor) and other proteins are recruited to the complex
- FtsI: peptidoglycan transpeptidase
- FtsK: chromosomal separation
FtsZ Complex - Answer - elongation occurs alongside septum formation
- GTP hydrolysis causes FtsZ ring to contract, forming the septum (splits bacteria in two)
, - after elongation is finished and the septum is formed, the FtsZ ring disassembles
- new cell envelope material is made at the septum to seal off the daughter cells from one
another
New Peptidoglycan (new cell wall) - Answer - during cell division, preexisting peptidoglycan
needs to be severed and newly synthesized peptidoglycan needs to be inserted
- bactoprenol is a hydrophobic C55 alcohol that is bonded to the peptidoglycan precursor
(NAG/NAM/pentapeptide) (this is called Lipid II complex)
- bactoprenol ensures peptidoglycan precursor can get through the cytoplasmic membrane to
the cell wall
- Lipid II goes through a transmembrane transporter called flippase (to the outside of the cell
where the peptidoglycan is)
Insertion of New Peptidoglycan - Answer - autolysins cleaves old peptidoglycan at the
NAG/NAM glycosidic bond (to create a space for the new peptidoglycan)
- transglycosylases are peptidoglycan polyymerases that interact with Lipid II by:
- inserting new peptidoglycan precursor into small gaps in the existing peptidoglycan made by
autolysins
- the new peptidoglycan is inserted at growing points of the cell wall
(cell wall is replaced little bits at a time as the cell divides and grows into a new cell)
Crosslinking of New Peptidoglycan - Answer - transpeptidation then occurs -- forms peptide
crosslink between NAM of adjacent NAG/NAM chains
- transpeptidation is a target of penicillin
Understand the unique characteristics of biofilms - Answer Biofilms: attached polysaccharide
matrices containing embedded bacterial cells
- high-density cell communities that embed themselves in a self-made matrix
- matrix made of sticky extracellular polymeric substances (EPS)
- very resistant to destruction
4 stages of Biofilm formation - Answer 1. Attachment - adhesion of a few motile
2. Colonization - intercellular communication, growth, and polysaccharide formation
3. Development - more growth and polysaccharide
4. Active Dispersal - triggered by environmental actors such as nutrient ability
Know the importance of endospores - Answer - some gram+ bacteria form endospores
Questions All Answered Correctly
2026 Updated.
Know the types of equal and unequal cell division - Answer Equal: binary fission
Unequal: budding
Budding division - Answer - a new cell emerges and buds off from a mother cell (daughter cell
is genetically identical but different in size/function from mother cell)
- some budding bacteria have cytoplasmic extensions
- in multiple fission, one hyphae has multiple locations of new cell growth along its length
Describe the steps of binary fission (bacterial DNA replication, molecular mechanism of septum
formation, steps of new peptidoglycan synthesis) - Answer - most bacteria grow asexually --
binary fission
- copies its chromosomes
- elongates
- splits into 2 daughter bacteria w/ identical genetic make up
Bacterial DNA Replication - Answer - semiconservative: every new DNA strand has one new
and one old strand
- bi-directional: circular DNA has two replication forks (creates a "theta" structure)
- bacteria initiate 2nd replication fork before 1st one is completed --> bacteria can replicate very
fast!
(when first replication is completes and new cells are made, DNA is already being replicated in
the daughter cells for the next cell divison)
FtsZ - Answer - FtsZ is a tubulin-like protein
- Division starts with FtsZ assembling to form a ring around the center of the cell
- FtsZ then interacts with ZipA to anchor the ring to the cytoplasmic membrane
- FtsA (actin-like protein, membrane anchor) and other proteins are recruited to the complex
- FtsI: peptidoglycan transpeptidase
- FtsK: chromosomal separation
FtsZ Complex - Answer - elongation occurs alongside septum formation
- GTP hydrolysis causes FtsZ ring to contract, forming the septum (splits bacteria in two)
, - after elongation is finished and the septum is formed, the FtsZ ring disassembles
- new cell envelope material is made at the septum to seal off the daughter cells from one
another
New Peptidoglycan (new cell wall) - Answer - during cell division, preexisting peptidoglycan
needs to be severed and newly synthesized peptidoglycan needs to be inserted
- bactoprenol is a hydrophobic C55 alcohol that is bonded to the peptidoglycan precursor
(NAG/NAM/pentapeptide) (this is called Lipid II complex)
- bactoprenol ensures peptidoglycan precursor can get through the cytoplasmic membrane to
the cell wall
- Lipid II goes through a transmembrane transporter called flippase (to the outside of the cell
where the peptidoglycan is)
Insertion of New Peptidoglycan - Answer - autolysins cleaves old peptidoglycan at the
NAG/NAM glycosidic bond (to create a space for the new peptidoglycan)
- transglycosylases are peptidoglycan polyymerases that interact with Lipid II by:
- inserting new peptidoglycan precursor into small gaps in the existing peptidoglycan made by
autolysins
- the new peptidoglycan is inserted at growing points of the cell wall
(cell wall is replaced little bits at a time as the cell divides and grows into a new cell)
Crosslinking of New Peptidoglycan - Answer - transpeptidation then occurs -- forms peptide
crosslink between NAM of adjacent NAG/NAM chains
- transpeptidation is a target of penicillin
Understand the unique characteristics of biofilms - Answer Biofilms: attached polysaccharide
matrices containing embedded bacterial cells
- high-density cell communities that embed themselves in a self-made matrix
- matrix made of sticky extracellular polymeric substances (EPS)
- very resistant to destruction
4 stages of Biofilm formation - Answer 1. Attachment - adhesion of a few motile
2. Colonization - intercellular communication, growth, and polysaccharide formation
3. Development - more growth and polysaccharide
4. Active Dispersal - triggered by environmental actors such as nutrient ability
Know the importance of endospores - Answer - some gram+ bacteria form endospores
