Prokaryotic Outline

Question 1

Overview of Prokaryotic Cell Structure

Answer 1

Exist in a wide variety of sizes, shapes, and cellular aggregation patterns
Simpler structure than eukaryotic cells
Has unique structures not observed in eukaryotes

Question 2

may occur as individuals, groups of 2 or more cells or chains, tetrads, clusters
may divide in 1 or more planes
circular

Answer 2

cocci

Question 3

rod shaped cells
coccobacilli
vibrio
single or may form short chains

Answer 3

bacillus

Question 4

curved rods -

Answer 4

vibrio

Question 5

may be “coccoid” in shape (very short rods)

Answer 5

coccobacilli

Question 6

rigid spiral shaped

Spirochetes

Answer 6

spirilla

Question 7

– flexible helices

Answer 7

Spirochetes

Question 8

network of long, multinucleate filaments

Answer 8

mycelia

Question 9

other weird shapes

Answer 9

Squares, Star-shapes, Triangular

Question 10

many shapes

Answer 10

pleomorphic

Question 11

Prokaryotic cells may form ______ after cell division

Answer 11

groupings

Question 12

Cells _______ _______ after cell division for characteristic arrangements

Answer 12

adhere together

Question 13

Arrangement depends on

Answer 13

plane of division

Question 14

Division along a single plane may result in pairs of cells or

Answer 14

diplococci

Example: Neisseria gonorrhoeae

Question 15

Division along a single plane may result in chains of cells

Answer 15

streptococci

Example: species of Streptococcus

Question 16

Division along two or three perpendicular planes form _____ or __________

Answer 16

tetrads;cubical packets

Question 17

Division along several random planes form

Answer 17

clusters

Question 18

Some bacteria live in groups with other bacterial cells; They form ________

Answer 18

multicellular associations

Question 19

examples of multicellular associations

Answer 19

myxobacteria, cyanobacteria

Question 20

what are the basic cell components

Answer 20

Cell wall 
Cell membrane
Cytoplasmic matrix
ribosomes
inclusion bodies
Nucleoid
External features (at least for some bacteria)

Question 21

Prokaryotic Cell Walls

Answer 21

• Rigid structure lying just outside the plasma membrane
• Mycoplasms and some Archaea lack cell walls
• Provides characteristic shape to cell
• Protects the cell from osmotic breakdown

Question 22

gram staining reaction results from differences in

Answer 22

the cell wall structure

Question 23

when and who developed the gram stain

Answer 23

Christian Gram (1884)

Question 24

Bacterial Cell Walls

Answer 24

• Rigidity of cell wall is due to peptidoglycan
o Compound found only in Bacteria
• Composed of glycan chains of disaccharide.
o Disaccharide consists of N-acetylglucosamine (NAG) & N-acetylmuramic acid (NAM)
• Glycan chains held together by tetrapeptide chains

Question 25

Tetrapeptide connections may contain

Answer 25

o D-isomers of amino acids o Diaminopimelic acid (DAP) Found no where else in nature

Question 26

Connection may be

Answer 26

direct or through a peptide interbridge

Question 27

gram positive cell wall

Answer 27

• Formed of a relatively thick layer of peptidoglycan o As many as 30 sheets o Despite the thickness, is permeable to numerous substances • Teichoic acids

Question 28

o polymers of glycerol or ribitol joined by phosphate groups o Joined to peptidoglycan via NAM o Stick out above peptidoglycan giving cell negative charge Lipoteichoic acids bind to the plasma membrane

Answer 28

teichoic acids

Question 29

gram negative cell wall

Answer 29

* Consist of a thin layer of peptidoglycan surrounded by an outer membrane * Outer membrane composed of lipids, lipoproteins, and lipopolysaccharide (LPS) * No teichoic acids

Question 30

what is the periplasmic space

Answer 30

Gap between plasma membrane and cell wall (gram-positive bacteria) or between plasma membrane and outer membrane (gram-negative bacteria)

Question 31

gel like substance that occupies periplasmic space

Answer 31

periplasm

Question 32

``` o found in periplasm of gram-negative bacteria o some of their functions include  nutrient acquisition  electron transport  peptidoglycan synthesis  modification of toxic compounds ```

Answer 32

periplasmic enzymes

Question 33

o secreted by gram-positive bacteria | o perform many of the same functions that periplasmic enzymes do for gram-negative bacteria

Answer 33

Exoenzymes

Question 34

Lipopolysaccharides

Answer 34

• Consist of three parts o O side chain (O antigen) o Core polysaccharide o Lipid A

Question 35

gram negative cell wall outer membrane

Answer 35

lipopolysaccharide layer (LPS layer)

Question 36

what is a lipid bilayer

Answer 36

outer leaflet made of lipopolysaccharides not phospholipids

Question 37

outer membrane serves as

Answer 37

barrier to a large number of molecules

Question 38

porin proteins

Answer 38

form channels through which small molecules (600-700 daltons) can pass

Question 39

outer membrane is more permeable than plasma membrane due to

Answer 39

presence of porin proteins and transporter proteins