Chapter 3 : Bacterial cell structure

Question 1

Bacteria have different arrangements, what are the names of the different cocci arrangements?

Answer 1

Cocci- spheres that are single or associated in arrangements

Diplococci- in pairs
Streptococci- chains of cocci divided in 1 plane
Staphylococci- random clusters
tetrads- divided into 2 planes to form a square
Sarcina- divided in 3 planes looks like a cube

Question 2

Bacteria have different arrangements, what are the names of the different bacilli arrangements

Answer 2

Coccobacilli- short and wide
Vibrios- comma shape

Question 3

what do spirilla look like?

Answer 3

rigid spiral shaped bacteria

Question 4

What do spirochetes bacteria look like?

Answer 4

flexible spiral shaped

Question 5

Organisms that are variable shape are called ?

Answer 5

Pleomorphic

Question 6

The plasma membrane and all its surrounding layers external to it is called?

Answer 6

cell envelope

Question 7

What does the cell envelope include?

Answer 7

capsule or slime layer
cell wall
plasma membrane

Question 8

Function of the plasma membrane

Answer 8

Selective permeability for getting nutrients and getting rid of waste

Question 9

How is the plasma membrane structured and what is the dynamic of it ?

Answer 9

composed of two lipids sheets 7 to 8 micrometers
Hydrophilic- polar interaction with water
Hydrophobic - non-polar and interact with each other

Question 10

Microbes can only take in dissolved particles across permeable membrane via what mechanisms?

Answer 10

Passive diffusion
facilitated diffusion
primary and secondary active transport
group translocation

Question 11

In passive diffusion, molecules move from a lower concentration to a higher concentration T o F.

Answer 11

f- They move from high to lower concentration

Question 12

What molecules are able to move easily via passive diffusion?

Answer 12

water, O2 and CO2

Question 12

What is the movement across the plasma membrane with the help of transport proteins called?

Answer 12

Facilitated diffusion

Question 13

What is the difference between channels and carrier proteins

Answer 13

Channel is pore-like in the membrane that allows the substance to pass through\
Carriers are more substrate-specificity

Question 14

Transports molecules against the concentration gradient and is an energy-dependent process of Atp or proton motive force

Answer 14

Active transport

Question 15

What is primary active transport?

Answer 15

Uses energy from ATP hydrolysis to move substances against gradient with no modifications

Question 16

What transport mechanism would you use do ATP binding cassette transporters and what do they consist of?

Answer 16

Primary active transport
2 hydrophobic spanning domains
2 cytoplasmic associated ATP binding domains

Question 17

Transport mechanism that uses potential energy of ion gradients to co-transport substance without modifying is?

Answer 17

secondary active transport

Question 18

What does the substance move through in a secondary transport mechanism?

Answer 18

symport
antiport

Question 19

Energy-dependent transport that chemically modifies the molecule as it is brought into the cell is ?

Answer 19

Group translocation

Question 20

best known translocation system is PTS, what occurs in this process?

Answer 20

it imports sugars while phosphorylating them

Question 21

What is the purpose for siderophore to be secreted by bacteria

Answer 21

help aid them in iron uptake since it is essential in building molecules

Question 22

Bacterial cell wall function

Answer 22

maintain shape
helps protect cells from osmotic lysis
no tonic materials
contribute pathogenicity

Question 23

what are the two alternating sugar that forms the meshlike polymer peptidoglycan

Answer 23

N-acetylglucosamine ( NAG
N-acetylmuramic acid ( NAM

Question 24

What composes the outer membrane of a gram-negative bacteria ?

Answer 24

lipids, lipoproteins and lipopolysaccharides

Question 25

Gram-negative bacteria contain teichoic acids in their cell wall T o F

Answer 25

False only gram postive

Question 26

What are the importances of LPS?

Answer 26

negative surface charge stabilize outer membrane permeability barrier host defense protection acts as endotoxin

Question 27

In hypertonic environments, water moves into the cell and swells T o F ?

Answer 27

False: water leaves cell and cytoplasm shrivels up

Question 28

What are the three parts that make up LPS?

Answer 28

Lipid A Core polysaccharide O side chain ( O antigen) O for out

Question 28

If cells are treated with lysozyme or penicillin what occurs to the bacterial cell?

Answer 28

They lyse in hypotonic solution due to the weakening of peptidoglycan

Question 29

What is the relationship between extracellular vesicles and bacteria?

Answer 29

small membrane-bound molecule that help in cell to cell interaction via transferring genetic information and toxin mol.

Question 30

additional layers that occur that bacteria have are?

Answer 30

capsules - polysaccharides well organized slime layer- polysaccharides unorganized Glycocalyx- polysaccharide extension to stick to surfaces S-layer- a geometric pattern of proteins aid in protection of ion and PH fluctuations

Question 31

Protective advantages of capsules

Answer 31

resistant to phagocytosis protect from desiccation

Question 32

advantages of slime layer in bacteria

Answer 32

facilitate motility

Question 33

formed rings at the center of a dividing cell that constricted as daughter separates is and example of what ?

Answer 33

Ftsz cytoskeleton molecule

Question 33

S- layer functions:

Answer 33

protect from ion and PH fluctuation prevent osmotic stress maintain shape and rigidity adhesion host defenses

Question 34

What is the purpose of the MreB cytoskeleton molecule?

Answer 34

maintain shape by positioning PEP. in synthesis machinery

Question 35

purpose of CreS cytoskeleton molecule

Answer 35

maintain curve shape

Question 36

The subunits for bacterial ribosome

Answer 36

It is composed of ribosomal RNA and protein 16s and 23s and 5s = 70s ribosome

Question 37

what contains the location of chromosomes and associated proteins?

Answer 37

Nucleoid

Question 38

What does the bacterial DNA look like?

Answer 38

1 closed circular DS DNA molecule

Question 39

The function of external structures in bacteria?

Answer 39

Protection attachment horizontal gene transfer cell movement

Question 39

Small circular piece of DS DNA that contains genes that can give bacteria advantage in some situations

Answer 39

Plasmids

Question 40

Describe what are pili and fimbriae

Answer 40

short, thin, hairlike, mediate motility attachment DNA Uptake

Question 41

What is the sex pili?

Answer 41

the external structure of the bacteria that can copy and send genetic material from another plasmid

Question 42

Thread like, locomotor appendages extending outward from plasma membrane and cell wall are called?

Answer 42

Flagella

Question 43

If a flagelllum is rotating CW what is the affect on the bacteria ?

Answer 43

disrupts run and causes cell to stop and tumble

Question 44

What is spirochete motility?

Answer 44

multiple flagella form axial fibril that surrounds cell

Question 45

What is chemotaxis?

Answer 45

Movement towards a chemical attractant or away

Question 46

In response to nutrient depletion in a bacterial cell, what forms?

Answer 46

Endospores

Question 47

What is the endospore structure?

Answer 47

Exosporium Spore coat- protein Cortex- Thick PEP Core- Nucleoid and ribosomes

Question 48

what does sporulation produce in a bacterial cell?

Answer 48

produces a dormant cell that can survive the harsh nutrient depleted environment