Module 3: Basic Characteristics of Bacteria

Question 1

Bacteria (Prokaryote)

Answer 1

• most function as independent single-celled organisms
• fully capable of carrying out all necessary life activities

Question 2

Bacterial Shapes

Answer 2

• coccus
• bacillus
• spirillum
• spirochete

Question 3

Cocci

Answer 3

round

Question 4

Bacilli

Answer 4

pill shaped

Question 5

Spirillum

Answer 5

squiggly

Question 6

Spirochete

Answer 6

tight spiral

Question 7

Bacteria Structures - Cell Wall

Answer 7

composed of peptidoglycan (long sugar chains-cross-linked by short protein)

Question 8

Bacteria Structures - All Bacteria

Answer 8

• cell (cytoplasmic) membrane
• bacterial chromosome or nucleoid
• ribosomes
• cytoplasm

Question 9

Bacteria Structures - Some Bacteria

Answer 9

• fimbriae
• cell wall
• pilus
• glycocalyx
• flagellum

Question 10

Gram Stain

Answer 10

bacteria from fresh culture is fixed to the microscope slide

Question 11

Gram Positive

Answer 11

stained purple

Question 12

Gram Negative

Answer 12

stained pink; has a outer membrane layer

Question 13

Gram Stain Procedure

Answer 13

1. Crystal Violet
2. Gram’s iodine
3. Alcohol
4. Safranin (red dye)

Question 14

Endospores

Answer 14

• are dominate bodies produced by bacteria such as Bacillus, Clostridium, and Sporosarcinpa
• can withstand hostile conditions (heat, drying, freezing, radiation, and chemicals)

Question 15

Sporulation

Answer 15

depletion of nutrients and environmental conditions can induce the bacteria to undergo endospore formation

Question 16

Germination

Answer 16

• endospores can be revitalized when favourable conditions return
• reverts back to fully functional bacteria

Question 17

Binary Fission

Answer 17

• the reproductive process in which one bacterial cell becomes two
• parent cell and daughter cell

Question 18

Generation Time

Answer 18

• aka doubling time
• the time required to complete a fission cycle - from one parent cell to new daughter cells

Question 19

bacterial growth stages - 4

Answer 19

1. lag phase
2. exponential phase
3. stationary phase
4. death phase

Question 20

Lag Phase

Answer 20

• population appears not to be growing
• period of adjustment, enlargement, and synthesis
• cells are still metabolically active and are preparing to divide

Question 21

Exponential Growth Phase

Answer 21

• maximum rate of division
• will continue with adequate nutrients and the environment is favourable

Question 22

Stationary Phase

Answer 22

• rate of cell birth and cell death are more or less equal
• deplete of nutrients and oxygen

Question 23

Death Phase

Answer 23

• cells die and are unable to multiply
• nutrient supply continually decreases
• waste product continually increase