Practice 1

Question 1

1. Differentiate flagella, axis filaments, fimbriae, and pili

Answer 1

Flagella: Flagella are relatively long filamentous appendages consisting of a filament, hook, and basal body.

Axial filaments: Spiral cells that move by means of an axial filament (endoflagella) are called spirochetes.

Fimbriae: helps cells adhere to surfaces. short and skinny

Pili: involved in twitching motility and DNA transfer. longer than fimbirae

Question 2

Long filamentous appendages consisting of a filament, hook, and basal body

Answer 2

Flagella

Question 3

What is the use of flagella

Answer 3

Rotate to push cells

Motile bacteria exhibit taxis, positive (attractant), negative (repellent)

Question 4

What repeats with units of one protein

Answer 4

Flagellin

Question 5

Chains wind together to make hollow filaments

Answer 5

flagella

Question 6

Name parts of flagella and how they connect

Answer 6

filament, hook, basal body

flagellin (protein) repeat and makes a chain of hollow filaments. attaches to basal body via hook

Question 7

Wrap underneath the cell

Answer 7

Axial filament

Question 8

Wrapped under cellular sheath, moves like a corkscrew

Answer 8

Axial filaments/ spirochete

Question 9

Help cells adhere to surfaces

Answer 9

Fimbriae

Question 10

Short, skinny, few or many attachements

Answer 10

Fimbriae

Question 11

Involved in twitching motility and DNA transfer

Answer 11

Pili

Question 12

What is longer fimbirae or pili

Answer 12

Pili

Question 13

Motion or sex (DNA transfer)

Answer 13

Pili

Question 14

2. Compare and contrast the cell walls of gram-positive bacteria and gram-negative

Answer 14

Cell wall surrounds plasma membrane and protects the cell from changes in water pressure

Gram-positive:
-thick peptidoglycan layer
-stronger
-easy to stain (purple)
-teichoic acid

Gram-negative:
-thin peptidoglycan layer located in periplasm
-includes outer membrane
-barrier to many drugs and stains
-toxic lipid A

Question 15

bacterial cell walls consist of what

Answer 15

peptidogylcan

Question 16

a polymer consisting of NAM and NAG, and short chain amino acids

Answer 16

peptidoglycan

Question 17

Which cell wall (+/-) consists of many layers of peptidoglycan

Answer 17

positive

Question 18

Which cell wall (+/-) consists of teichoic acids

Answer 18

positive

Question 19

Which cell wall (+/-) have a lipopolysaccharide-lipoprotein-phospholipid

Answer 19

negative

Question 20

Which cell wall (+/-) has a outer membrane

Answer 20

negative

Question 21

Which cell wall has a thin layer of peptidoglycan

Answer 21

negative

Question 22

what protects a cell from phagocytosis

Answer 22

outer membrane

Question 23

Which cell is protected from phagocytosis, penicillin, lysozyme, and other chemicals

Answer 23

negative

Question 24

What makes the lipopolysaccharide component of the outer membrane toxic and the lipid A

Answer 24

The lipopolysaccharide component of the outer membrane consists of sugars (O polysaccharides), which function as antigens,

and lipid A, which is an endotoxin.

Question 25

Which gram cell wall stains purple and which stains pink

Answer 25

purple: Gram-Positive
pink: Gram-Negative

Question 26

Why does gram-positive stain purple

Answer 26

-the thick layer of peptidoglycan in cell walls
-retains the crystal violent

Question 27

Why does gram-negative stain pink

Answer 27

-structure of cell wall (peptodogylcan is thin)
-unable to retain color
-retains counterstain making it appear pink

Question 28

Why does penicillin not work on gram-negative

Answer 28

the outer membrane of gram-negative prevents the uptake of penicillin

Gram-negative bacteria have a lipopolysaccharide and protein layer that surrounds the peptidoglycan layer of the cell wall, preventing penicillin from attacking.

Question 29

3. The question under Figure 5.19 asks, “What is the difference between homolactic and heterolactic fermentation?”

Answer 29

Homolactic Fermentation: any organisms that produces only lactic acid from fermentation

Heterolactic: any organisms that produce lactic acids, other acids, or alcohols as the final products from fermentation. often use pentose phosphate pathway

Question 30

4. The question under Figure 5.17 asks, “How do aerobic and anaerobic respiration differ?”

Answer 30

-aerobic respiration: oxygen is used as the final electron acceptor in ETC (produce much for ATP) and glucose in broken into CO2 and H2O

-anaerobic: other inorganic molecule (not oxygen) is used for the final electron acceptor in ETC (less ATP) may include nitrate and sulfate acceptors

Question 31

Homlactic Fermenation

Answer 31

organisms that produce only lactic acid from fermentation

Question 32

Heterlocatic fermentation

Answer 32

organic produces lactic acid, other acids, or alcohols as the final product
- often use pentose phosphate pathway

Question 33

organism that produces only lactic acid from fermentation

Answer 33

homolactic fermentation

Question 34

organims that produces latic acids, other acids, or alcohols as final products of fermentation

Answer 34

heterlocatic fermentaiton

Question 35

Aerobic repiration

Answer 35

Oxygen is the final electron acceptor

Question 36

Anaerobic respiration

Answer 36

other inorganic molecules (not Oxygen) are the final electron acceptors in ETC