bacte

Question 1

Form small hydrophilic channels through the outer envelope allowing the diffusion neutral and charged solutes of MW <600 daltons ● Three identical units ● Associate to form membrane holes

Answer 1

porins

Question 2

mediate interconnection between the OM and murein ● synthesized within the cell and contains a leader sequence of 20 amino acids at its amino terminal end ● after transport through the CM, the leader sequence is removed and the terminal residue is modified to make it hydrophobic > − facilitates integration into the OM

Answer 2

lipoproteins

Question 3

proteins in OM are used as attachment sites by ______

Answer 3

bacteriophages

Question 4

outer surface bacteria’s outer membrane with strong negative charge is important in evading ______________

Answer 4

phagocytosis

Question 5

bacterial endotoxin causing a variety of pathophysiological reactions ranging from fever to death

Answer 5

LPS complex

Question 6

A separate compartment between the cell membrane and outer membrane in Gram (-) bacteria

Answer 6

periplasm

Question 7

activities of periplasm

Answer 7

activites: ● redox reactions ● osmotic regulation ● solute transport ● protein secretion ● hydrolysis

Question 8

thought to be involved in the osmotic regulation of the periplasm because their amounts decrease when the cells are grown in media of high osmolarity

Answer 8

oligosaccharides

Question 9

bind to solutes and deliver solutes to specific transporters in the membrane

Answer 9

solute binding proteins

Question 10

degrade nutrients to smaller molecules that can be transported across the membrane by specific transporter

Answer 10

hydrolytic enzymes

Question 11

required for the uptake of several solutes (iron siderphores, vit B,2) that do not diffuse through the porin

Answer 11

TonB Proteins

Question 12

●Most dynamic structure of a prokaryotic cell
● Definitive structure of the cell
● Has a variety of functions in energy generation and biosynthesis
● Contains transport proteins, binding proteins, sensing proteins and enzymes involved in metabolic processes
● Absolute requirement of a living organisms
● Chief point of contact with the environment

Answer 12

plasma membrane

Question 13

most membrane associated lipids are structurally assymetric

Answer 13

phospholipids

Question 15

For every 1 g of cells:

Answer 15

91 mg phospholipid
129 umole phosphatidylethanolamine
where: 1 umole = 750 ug PE

Question 16

● major phospholipid in the cytoplasmic membrane
● formed from glycerol-3-P, serine and fatty acids in the ratio of 1:1:2

Answer 16

phosphatidylethanolamine

Question 17

● next most prevalent
● formed from glycerol-3-P and fatty acids in equimolar ratios

Answer 17

phosphatidylglycerol

Question 18

two types of membrane proteins

Answer 18

integral proteins
peripheral proteins

Question 19

• embedded in the CM
• amphipathic
• bound to the fatty acids of the phospholipids via hydrophobic bonding

Answer 19

integral proteins

Question 20

attached to membrane surfaces by ionic interactions

Answer 20

peripheral proteins

Question 21

most widely accepted model of the cell membrane

shows that the cell membrane is a lipid bilayer with which proteins and lipids “float”mfreely

Answer 21

Fluid Mosaic Model

Question 22

consists of aqueous solution
a. macromolecules
b. small molecules which serve as energy sources, precursors of macromolecules, metabolites or vitamins
c. various organic and inorganic ions and cofactors

Answer 22

cytoplasm

Question 23

structural components of bacteria’s cytoplasm

Answer 23

nucleoid
ribosomes
inclusion bodies

Question 24

cytoskeletal filaments are structurally similar to their eukaryotic counterparts

Answer 24

prokaryotic cytoskeleton

Question 25

FtsZ (tubulin)

Answer 25

cell division

Question 26

MreB (actin)

Answer 26

cell shape

Question 27

Cresentin (intermediate filament proteins)

Answer 27

cell shape

Question 28

invaginations of the plasma membrane in the shape of vesicles, tubules or lamellae believed to be involved in cell septum formation electron transport, photosynthesis, cell wall formation, DNA replication and segregation and sporulation

Answer 28

Mesomes

Question 29

distinct bodies that may occupy a substantial part of the cytoplasm may be organic or inorganic some inclusion bodies lie free in the cytoplasm or enclosed by a shell consisting of proteins or a membranous structure composed of proteins and phospholipids usually used for storage

Answer 29

inclusion bodies

Question 30

a polymer of glucose units composed of long chains formed by a 1,4 glycosidic bonds and branching chains connected to them by a 1,6 glycosidic bonds.

Answer 30

glycogen

Question 31

contains b-hydroxybutyrate molecules joined by ester bonds

Answer 31

poly-b-hydroxybutyric acid (PHB)

Question 32

composed of large polypeptides containing approximately equal amounts of amino acids arginine and aspartic acid

Answer 32

cyanophycin granules

Question 33

polyhedral bodies about 100 nm in diameter contain the enzyme ribulose-1,5-bisphosphate carboxylase may serve as site for CO, fixation

Answer 33

carboxysomes

Question 34

ellipsoidal vesicles where photosynthetic pigments are located attached to the plasma membrane but not continuous with it

Answer 34

chromosomes

Question 35

linear polymer of orthophosphates joined by ester bonds function as storage reservoirs for phosphates or as energy reserve

Answer 35

polyphosphate granules (volutin or metachromatic granules)

Question 36

used to store sulfur temporarily accumulate in the periplasmic space of in special cytoplasmic globules

Answer 36

sulfur granules

Question 37

small, hollow, cylindrical structures composed entirely of a single small protein impermeable to water but freely permeable to gases

Answer 37

gas vesicles

Question 38

intracellular chains of magnetite (Fe3O4), greigie (Fe3S4) or pyrite (FeS2) particles bounded by a membrane aids in orienting bacteria in the earth's magnetic field

Answer 38

Magnetosomes