L12 Bacteria & Archaea pt 1

Question 1

what are prokaryotes?

Answer 1

simple, ancient, successful, all-over organisms that do not have a nucleus nor membrane bound organelles

Question 2

what is included in the internal structure of a bacterial cell?

Answer 2

-cytoplasm
-specialized membranes
-genome organization (nucleoid region with one circular chromosome)
-plasmids
-ribosomes

Question 3

what is included in the external structure of a bacterial cell?

Answer 3

-plasma membrane
-cell well (peptidoglycan)
-flagella
-capsule
-pili

Question 4

how is bacterial diversity generated?

Answer 4

-mutations
-recombination through vertical gene transfer (mitosis)
-horizontal gene transfer

Question 5

what are the metabolic roles of the prokaryotes?

Answer 5

regulating biogeochemical nutrient cycles (carbon, nitrogen, oxygen, sulfur) and waste cycles

Question 6

how are prokaryotes classified?

Answer 6

through 2 domains based on structure, physiology, and biochemistry: archaea and bacteria

Question 7

describe the size of prokaryotes and why it is that way

Answer 7

smaller than avrg eukaryotic protists, plant, fungal, and animal cell

-surface area to volume ratio (b/c of diffusion limits) causes it to remain in the 2nm to 2um range

Question 8

prokaryotes are ____________ simple, but ____________ diverse. Why?

Answer 8

morphologically; metabolically

-have basic shapes
-have complex role in chemical cycles + help recycle nutrients on earth

Question 9

describe bacteria in 3 ways

Answer 9

unicellular, simple shapes, very small in size (2nm to 2um)

Question 10

what are the simples shapes of bacteria

Answer 10

coccus (spherical), bacillus (rod), and spirillus (helix)

Question 11

name the types of horizontal gene transfer

Answer 11

conjugation, transformation, transduction (viruses)

Question 12

describe the process of conjugation; what can it be used for

Answer 12

plasmids (DNA) transfer between cells through thinly synthesized cytoplasm strands (pili)

-spreading novel genes in bacterial populations (i.e. antibiotic resistance)
-plasmids used for GMOs/ genetic eng

Question 13

describe the process of transformation

Answer 13

DNA is released into the environment by a dead donor, which is accepted by a recipient cell

Question 14

describe the process of transduction

Answer 14

a donor is infected with a virus, which transfers genes (e.g. its own + additional bacterial DNA with them) to a recipient cell

-often used in research labs

Question 15

photosynthesis is ________, cellular respiration is ___________

Answer 15

oxygenic; aerobic

Question 16

carbon cycling is linked to __________. what are six types of carbon cycling?

Answer 16

other cycles (e.g. oxygen cycling)

-involving oxygenic photosynthesis and aerobic cellular respiration
-anoxygenic photosynthesis
-chemoautotropy
-fermentation
-anaerobic respiration

Question 17

what organism led to the oxygenic photosynthesis evolution

Answer 17

cyanobacteria

Question 18

explain what an autotroph is and what groups it is divided into

Answer 18

self-feeders + producers

-divided into photoautotroph and chemoautotroph

Question 19

explain what a heterotroph is and what groups it is divided into

Answer 19

“other feeders”, consumers / decomposers

• divided into photoheterotroph and chemoheterotroph

Question 20

what is a photoautotroph and what are some examples

Answer 20

uses light as energy source, CO2 as carbon source and includes photosynthetic prokaryotes like cyanobacteria; plants; certain protists like algae

Question 21

what is a chemoautotroph and what are some examples

Answer 21

uses inorganic chemicals as energy source, CO2 as carbon source, and includes certain prokaryotes (e.g. sulfolobus)

Question 22

what is a photoheterotroph and what are some examples

Answer 22

uses light as energy source, organic compounds as carbon source, and includes certain prokaryotes (e.g. rhodobacter, chloroflexus)

Question 23

what is a chemoheterotroph and what are some examples

Answer 23

uses organic compounds as energy source and carbon source, and includes most prokaryotes (e.g. clostridium); fungi; animals; some plants

Question 24

what is a microbial mat? describe the layers of this

Answer 24

a multi-layered sheet of prokaryotes that includes mostly bacteria, but also archaea

-surface layers use oxygenic photosynthesis and aerobic cellular respiration
-deeper layers use anoxygenic photosynthesis and anaerobic respiration and fermentation

Question 25

anoxygenic photosynthesis; what pigment is used; structure/flow; e- donors?

Answer 25

photosynthesis in which O2 is not produced

-sunlight absorbed uses bacteriochlorophyll pigment
-has one photosystem and ETC to only make ATP
-electron donors are H2S, H2, Fe+2 (ferrous iron) and AsO3 -3 (arsenite)

Question 26

anaerobic respiration (fermentation); e- acceptors?

Answer 26

Form of cellular respiration in which some decomposers get the energy they need through the breakdown of glucose (or other nutrients) in the absence of oxygen

-oxidants are reduced using electron acceptors like Fe +3 (ferric iron), sulfate, nitrous oxide, manganese, arsenate

Question 27

what is the role of bacteria in the nitrogen cycle

Answer 27

Bacteria convert (fix) atmospheric nitrogen into ammonia and ammonium, and then into nitrate (through nitrification) so it can be used by plants.

Question 28

sulfur cycle; what is the role H2S

Answer 28

Cyclic movement of sulfur in various chemical forms from the environment to organisms and then back to the environment.

-H2S quickly oxidized to sulfur when O2 is present
-H2S is toxic to eukaryotic organisms