Prokaryotic Cells (Bacteria and Archaea)

Question 1

Some examples of prokaryotes

Answer 1

bacteria and archea

Question 2

type of chromosomes prokaryotes have

Answer 2

one circular chromosome

Question 3

Some characteristics of prokaryotic cells

Answer 3

-no nuclear membrane
-plasma membrane acts as mitochondrial membrane
-organelles are absent
-genetic material in single circular chromosome
-no histone proteins (eukaryotes hmr pl shi)
-cell wall is made up of carbohydrates and amino acids (polysaccharides)
-divide asexually by binary fission, sexually by conjugation

Question 4

Where is genetic material present?

Answer 4

-in a nucleoid (spherical, rod-shaped or spiral)
-single circular chromosome

Question 5

What is capsule? What does it do?

Answer 5

-outer protection found in bacterial cells
-outside of the cell wall
-moisture retention, protection, attachment

Question 6

What is the cell wall in prokaryotes?

Answer 6

-outer layer of cells that gives shape
-protects and prevents bursting

Question 7

Component of cell walls in bacteria

Answer 7

-peptidoglycans => polymer of linked sugars and polypeptides

Question 8

Unusual fact about peptidoglycans

Answer 8

-contains both L and D amino acids
-L is the common one in making proteins

Question 9

Peptidoglycans are present in which prokaryotes?

Answer 9

-bacteria
-archaeal cell walls dont have them

Question 10

What do archaeal cell walls have?

Answer 10

-pseudopeptidoglycan
-polysaccharides (sugars)

Question 11

What is cytoplasm composed of?

Answer 11

-enzymes, salts and cell organelles

Question 12

What does cell membrane (plasma membrane do)?

Answer 12

-surrounds cytoplasm
-regulate entry and exit of substances

Question 13

What is plasma membrane made up of (bacteria)?

Answer 13

-phospholipid bilayer

Question 14

What is phospholipid( bacteria)?

Answer 14

-lipid composed of glycerol molecule attached to hydrophilic phosphate head and 2 hydrophobic fatty acid tails

Question 15

What are pili?

Answer 15

-hair-like outgrowth used for attachment to surfaces

Question 16

examples of bacterial pili

Answer 16

1. sex pilus
   -allows DNA to transfer between 2 cells in conjugation process
2. type IV pili
   -helps bacterium move in environment

Question 17

What is a flagellum?

Answer 17

-structures that help with locomotion
-whip-like

Question 18

What are ribosomes?

Answer 18

-involved in protein synthesis

Question 19

What are plasmids?

Answer 19

-non-chromosomal double-stranded DNA structures/not involved in reproduction (extra chromosomal DNA)
-smaller than chromosomal DNA

Question 20

What do plasmids do?

Answer 20

-carry genes for enzyme production

Question 21

What is nucleoid region?

Answer 21

-where genetic material is present in prokaryotes
-does not have a membrane

Question 22

What are fimbriae?

Answer 22

-thin filaments used for adhesion

Question 23

cell projections in prokaryotes

Answer 23

flagella, pili, fimbriae, cilia

Question 24

4 main components of prokaryotic cells?

Answer 24

-plasma membrane
-cytoplasm
-DNA
-ribosomes

Question 25

How do prokaryotes (bacteria) reproduce?

Answer 25

-asexually by binary fission -sexually by conjugation

Question 26

Explain binary fission.

Answer 26

-Mature parent cells split into 2 identical daughter cells -used for propagation (simple and fast) -starts at replication origin and duplicate the genome -duplicated genome segregate into two separate ends of cell -plasma membrane grows inward to form a septum -after septum formation, 2 daughter cells

Question 27

Explain conjugation.

Answer 27

-sexual reproduction method to directly transfer genetic material -via conjugation tube or via direct contact -two cells are donor cell and recipient cell -plasmid of donor cell comes near the sex pilus and nicks from one point to become single stranded -the strand goes into the recipient through the tube -both cells covert the DNA into double strand by synthesizing complementary strand

Question 28

What do donor cells have?

Answer 28

-fertility factor (F factor) needed to develop the sex pilus

Question 29

Where are antibiotic resistant genes located?

Answer 29

-plasmid DNA of bacteria

Question 30

What are endospores?

Answer 30

-tough dormant structures, help bacteria survive during unfavorable conditions

Question 31

Where is archaeal cell found?

Answer 31

-extreme environment such as hot springs, soil, marshes, even human

Question 32

chromosomes in archaea

Answer 32

single circular chromosome (circular double stranded DNA)

Question 33

initiator tRNA in bacteria and archaea

Answer 33

bacteria- formyl-,methionine archaea - methionine

Question 34

calvin cycle

Answer 34

-exist in bacteria -none in archaea

Question 35

What is plasma membrane made up of in archaea?

Answer 35

-glycerol is linked with phytanyl units rather than fatty acids -tends to be lipid monolayer some time

Question 36

2 major groups of bacteria

Answer 36

gram positive and gram negative based on gram stain reaction (used to determine the category based on the type of cell wall)

Question 37

cell wall of gram positive bacteria

Answer 37

-thick cell wall -has teichoic acids

Question 38

cell wall of gram negative bacteria

Answer 38

-thin cell wall -lipopolysaccharide and lipoproteins

Question 39

what are phototrophs

Answer 39

get energy from light/the sun

Question 40

what are chemotrophs

Answer 40

get energy from chemical compounds

Question 41

autotrophs

Answer 41

get energy by fixing carbon from carbon dioxide inorganic compounds

Question 42

heterotrophs

Answer 42

get carbon from organic compounds of other organisms

Question 43

nutrition mode of bacterium thiobacillus concretivorans

Answer 43

consume metal-melting sulfuric acid

Question 44

plants nutrition mode

Answer 44

photoautotrophs

Question 45

humans nutrition mode

Answer 45

chemoheterotrophs

Question 46

prokaryotes nutrition modes

Answer 46

all 4 categories photoauto, photohetero, chemoauto, chemohetero

Question 47

what are obligate aerobes?

Answer 47

organisms that require oxygen for metabolism

Question 48

what are obligate anaerobes?

Answer 48

organisms that can't tolerate oxygen and only perform anaerobic metabolism

Question 49

prokaryotic example of an obligate anaerobe

Answer 49

-bacterium called C. botulinum -causes botulism (food poisoning) when it grows inside canned food because they multiply well inside sealed cans

Question 50

what are facultative anaerobes

Answer 50

-aerobic metabolism when O2 is there, anaerobic when theres no O2

Question 51

bacteria example of facultative anaerobes

Answer 51

bacteria that cause staph and strep infections

Question 52

what is carbon cycle?

Answer 52

physical cycle of carbon through earth's biosphere, geosphere, hydrosphere and atmosphere -involved photosynthesis, decomposition, respiration and carbonification

Question 53

what is nitrogen cycle?

Answer 53

-atmospheric nitrogen is is converted to nitrogen oxides and deposited in the soil, is used by organisms and decomposed back to elemental nitrogen

Question 54

what is nitrogen fixation?

Answer 54

-conversion of atmospheric nitrogen into ammonia and organic derivatives by soil microorganisms, made usable