3. Composition of microbial world 2

Question 1

Prokaryotes

Answer 1

• bacteria, archea
  – similar in size and shape
• lack membrane-bound nucleus
• lack membrane-bound organelles

Question 2

Bacteria

Answer 2

• prokaryotic
• peptidoglycan cell walls
• gram-positive; gram-negative
  – structure of cell wall
  – gram-negative can be antibiotic resistent

Question 3

what are peptidoglycan cell walls

Answer 3

• combination of peptide bonds & carbohydrates
  – peptide (amino acids)
  – glycan (sugars)
• attacked by pennisylin

Question 4

what are the arrangements of bacteria cells

Answer 4

• coccus (spherical)
• bacillus (rod shaped)
• spirillium (sprial)
• vibrio (crescent like)
• spirochete
• filamentous bacteria
• cells will clump together if growth conditions are not good
  – formations depends on growth conditions

Question 5

how to bacteria reproduce

Answer 5

• binary fission
  – daughter cells identical to mother

Question 6

how does binary fission work

Answer 6

• replication of DNA
  – duplication of chromosome
• cell growth
  – continued cell growth of cell
• segregation of DNA
• splitting of cells
  – division into two cells

Question 7

what are archaea

Answer 7

• prokaryotic
• diverse physiology
• range of single cell morphologies to filaments and even aggregates (0.1 - 15 micrometers)
• hard to culture for biologists in lab conditions

Question 8

how do archaea have diverse physiology

Answer 8

• found to live in extreme environments
  – hot springs
  – geysers
  – gamma rays / UV radiation

Question 9

what do archaea include

Answer 9

• methanogens
• extreme halophiles
• extreme thermophiles

Question 10

how do archaea differ from bacteria

Answer 10

• cell wall structure
  – lacks peptidoglycan
• unique membrane lipid structure

Question 11

how is archaea membrane structure unique

Answer 11

• unique lipid structure
• side chains connected to glycerol backbone by ether bonds
  – instead of ester
• side chains branched
  – phytanyl sidechain
  – sometimes form monolayer membrane
• ether linkages vs. ester linkages

Question 12

what are eukaryotes

Answer 12

• multicellular / unicellular
• true membrane-bound nuclei
• DNA orgaises into chromosomes
• cell reproductions by mitosis and meiosis
• specific cellular functions in different organelles
  – eg. mitochondria respiration
  – eg. chloroplast photosythesis

Question 13

how are eukaryotic cellular functions specific in different organelles?

Answer 13

• specific cellular functions in different organelles
  – eg. mitochondria respiration
  – eg. chloroplast photosythesis

Question 14

what are fungi

Answer 14

• multi/unicellular
• saprophytes
• rigid cell walls (non-motile)
• filamentous (hyphae)
• secrete degradative enzymes into environments —- cellulases
  – proteases
  – amylases

Question 15

what are fungi cell walls made up of

Answer 15

• chitin
  – complex polysaccharide

Question 16

what are fungi applications

Answer 16

• pulp and paper industry
• food industry (penicillium roqueforti - in cheese)

Question 17

what is yeast

Answer 17

• unicellular
• cell wall of chitin
• asexual/sexual reproduction

Question 18

what are the applications of yeast

Answer 18

• food industry
  – beer, cheese, bread
• pharmaceutical industry
  – recombinant proteins

Question 19

what are microalgae

Answer 19

• unicellular
• asexual / sexual reproduction
• photosynthetic
  – chloroplasts
  – sequester CO2

Question 20

what are the applications of microalgae

Answer 20

• pharmaceutical
  – omega 3 fatty acids
• biofuel
  – biodiesel
• food industry
  –pigments

Question 21

what are viruses

Answer 21

• acellular
• DNA / RNA core
• enclosed by coat of proteins
  – may be lipids

Question 22

what is the coat of viruses

Answer 22

• coat of proteins
• may be closed by lipid envelope

Question 23

how do viruses reproduce

Answer 23

• only within living cells

Question 24

how are viruses classified

Answer 24

• nucleic acids characteristics
• capsid symmetry
• their host
• diseases they may cause

Question 25

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - Nuclear envelope

Answer 25

- absent - absent - present

Question 26

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - Membrane-enclosed organelles

Answer 26

- absent - absent - present

Question 27

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - peptidoglycan in cell wall

Answer 27

- present - absent - absent

Question 28

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - membrane lipids

Answer 28

- unbranched hydrocarbons - some branched hydrocarbons - unbranched hydrocarbons

Question 29

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - RNA polymerase

Answer 29

- one kind - several kinds - several kinds

Question 30

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - Initiator amino acid for protein synthesis

Answer 30

- formyl-methionine - methionine - methionine

Question 31

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - introns in genes

Answer 31

- very rare - present in some genes - present in many genes

Question 32

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - Response to antibiotics streptomycin and chloramphenicol

Answer 32

- growth inhibited - growth not inhibited - growth not inhibited

Question 33

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - histones associated with DNA

Answer 33

- absent - present in some species - present

Question 34

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - circular chromosome

Answer 34

- present - present - absent

Question 35

how are the three domains of life compared? Bacteria, Archaea, Eukarya: - Growth at temperatures >100 'C

Answer 35

- no - some species - no