Module 3: Section 1A

Question 1

Binary fission

Answer 1

• Process where a cell divides asexually to produce two daughter cells

Question 2

Binary fission process in bacterial cells

Answer 2

1. Begin with the replication of the bacterial chromosome as the individual cell grows
2. Further cell growth leads to an infolding of the cell wall
3. two separate daughter cells are pinched off

Question 3

Peptidoglycan

Answer 3

-Rigid cellular component
- Helps maintain bacterial cell shape and overall cellular integrity

Question 4

Old pole

Answer 4

The end of the cell that is inherited from the line of mother cells, as opposed to the newly synthesized pole

Question 5

4 causes of bacterial aging

Answer 5

1. Inheriting old cell wall material at the old pole
2. Inheriting damaged DNA
3. Inheriting damaged proteins
4. Activation of damage defence systems rather than growth systems

Question 6

Septal poles

Answer 6

Location of division of cell wall during binary fission

Question 7

Mother lineage

Answer 7

Cells with old poles that inherit damaged components; divide slowly and focus on survival

Question 8

Daughter lineage

Answer 8

Cells with new poles; divide faster and outcompete Mother cells

Question 9

Anabolism

Answer 9

• The building of components
• Consumes energy
• Like protein, DNA, etc

Question 10

Catabolism

Answer 10

• Breakdown of molecules to obtain energy

Question 11

5 factors that impact microbial metabolism

Answer 11

1. Temperature
2. pH
3. Water availability
4. Pressure
5. Oxygen levels

Question 12

When can denaturing occur?

Answer 12

If temperature, pH, pressure or water availability change away from their optimal levels

Question 13

Reactive Oxygen Species (ROS)

Answer 13

Toxic oxygen derivatives formed when O₂ gains electrons from cellular proteins

Question 14

Examples of ROS

Answer 14

• Superoxide radical
• hydrogen peroxide
• hydroxyl radical

Question 15

Damage from ROS

Answer 15

Damages proteins, lipids, and nucleic acids, contributing to cellular aging