Bio 2 Ch. 27

Front 1

What are microbes?

Back 1

microscopic organisms

Front 2

Total number of bacteria and archaea alive today?

Back 2

5 X 10^30

Front 3

3 domains of the tree of life?

Back 3

Bacteria, Archaea, and Eukarya

Front 4

Describe Bacteria.

Back 4

Bacteria are prokaryotic. They have cell
walls made of peptidoglycan, plasma
membranes similar to those of eukaryotes,
and distinct ribosomes and RNA
polymerase.

Front 5

Describe Archaea.

Back 5

Archaea are prokaryotic and unicellular.
They have call walls made of
polysaccharides, unique plasma
membranes, and ribosomes and RNA
polymerase similar to those of eukaryotes.

Front 6

Bacteria that cause disease are said to be _______?

Back 6

pathogenic

Front 7

What are antibiotics?

Back 7

molecules that kill bacteria.

Front 8

Describe what it means to be anoxic.

Back 8

means lacking oxygen

Front 9

What is bioremediation?

Back 9

Bioremediation is the use of bacteria and archaea to
degrade pollutants by (1) fertilizing contaminated sites to
encourage the growth of existing bacteria that degrade
toxic compounds, and (2) adding specific species of
bacteria to contaminated sites.

Front 10

Extremophiles

Back 10

bacteria or archaea that live in extreme environments.

Front 11

Development of an Oxygen Atmosphere.

Back 11

No free molecular oxygen existed for the first 2.3
billion years of Earth's history

Front 12

Cyanobacteria

Back 12

a lineage of photosynthetic bacteria,
were the first organisms to perform oxygenic
(oxygen-producing) photosynthesis.

Front 13

Many bacteria and archaea must obtain their nitrogen from _______ or _________?

Back 13

ammonia (NH3) or nitrate (NO3)

Front 14

How Do Biologists Study Bacteria and Archaea?

Back 14

•Enrichment cultures are based on establishing a
specific set of growing conditions and are used to isolate
new types of bacteria and archaea (Figure 27.7).
•Direct sequencing is a strategy for documenting the
presence of bacteria and archaea that cannot be grown in
culture and studied in the laboratory (Figure 27.8).

Front 15

A tree of life based on morphology has only two divisions: ____ and ____

Back 15

prokaryotes and eukaryotes.

Front 16

T or F?
The tree of life based on ribosomal RNA
sequences shows three
domains—Archaea, Bacteria, and
Eukarya—and is now accepted as correct.

Back 16

True!

Front 17

T or F?
Archaea and Bacteria are more closely related to each other than to Eukarya.

Back 17

False! •The first lineage to diverge from the common
ancestor of all living organisms was the
Bacteria; the Archaea and Eukarya are more
closely related to each other than to the
Bacteria.

Front 18

Study table 27.2 in book.

Back 18

DO IT!

Front 19

What does gram staining do?

Back 19

distinguishes bacteria by the type of cell wall.

Front 20

T or F?
Gram positive cells are pink.

Back 20

False

Front 21

T or F?
Gram negative cells are pink.

Back 21

True

Front 22

All bacteria and archaea are haploid and
reproduce by _______—the splitting of a cell into
two daughter cells.

Back 22

Fission

Front 23

Conjugation tube

Back 23

forms between cells
that are transferring and receiving a plasmid is a
morphological trait that is unique to bacteria and
archaea.

Front 24

What happens when conjugation occurs in bacterial cells?

Back 24

(the act of joining) occurs, a copy of a
plasmid—and potentially one or more genes from
the main bacterial chromosome—moves from one
cell to a recipient cell.

Front 25

What are plasmids?

Back 25

extracellular loops of DNA

Front 26

Bacteria and Archaea produce ATP in how many ways?

Back 26

3

Front 27

Describe Phototrophs.

Back 27

They can use light energy. ATP is
produced by photophosphorylation.

Front 28

Describe Organotrophs.

Back 28

They oxidize organic molecules, such as
sugars. ATP is produced by cellular respiration or
fermentation.

Front 29

Describe Lithotrophs.

Back 29

They oxidize inorganic molecules, such as
ammonia or methane. ATP is produced by cellular
respiration with the inorganic compound serving as
the electron donor.

Front 30

What are Autotrophs?

Back 30

Organisms that manufacture their own carbon-containing compounds.

Front 31

What are Heterotrophs?

Back 31

Organisms that acquire carbon-containing compounds by consuming other organisms.

Front 32

Cellular Respiration: Variation in Electron
Donors and Electron Acceptors

Back 32

•In cellular respiration, a molecule
with high potential energy serves as
an electron donor and is oxidized,
whereas a molecule with low
potential energy serves as a final
electron acceptor and is reduced.
The potential energy difference is
converted into ATP

Front 33

What is fermentation?

Back 33

It is a strategy for making
ATP without using electron transport
chains.
•In fermentation, no electron acceptor is
used; redox reactions are internally
balanced.

Front 34

What is photosynthesis?

Back 34

•Through photosynthesis, phototrophs can
use the energy in light to synthesize ATP.
•Photosynthetic bacteria can use many
different wavelengths of light for
photosynthesis.

Front 35

Some bacteria use the ______ _______to transform carbon dioxide to
organic molecules (same as plants).

Back 35

Calvin Cycle.
•Other bacteria obtain carbon by
absorbing organic compounds
released in dead tissues.

Front 36

Describe Methanotrophs

Back 36

•Methanotrophs use methane as
their primary electron donor and
carbon source. Other bacteria can use
carbon monoxide or methanol.

Front 37

Describe Spirochaetes (or spirochetes)

Back 37

• The spirochaetes (or spirochetes) are a phylum of
distinctive bacteria, which have long, helically coiled
cells.
•They are chemoheterotrophic in nature.
•Spirochetes are distinguished by their corkscrew shape
and unusual flagella.
•Important members of this phylum include
–Leptospira species, which causes leptospirosis
–Borrelia burgdorferi, which causes Lyme disease
–Treponema pallidum, which causes syphilis.
•Spirochaetes are gram-negative bacteria

Front 38

Describe Chlamydiales

Back 38

• Chlamydiales are spherical and
very tiny.
•They all live as parasites inside
animal cells.
•Chlamydia trachomatis is a common
sexually transmitted disease in
humans that can cause blindness.

Front 39

Describe High-GC (guanine and cytosine) Grampositive
bacteria

Back 39

• High-GC (guanine and cytosine) Grampositive
bacteria have various shapes, and
many soil-dwelling species form mycelia
(branched filaments).
•Streptomyces (genus) has many species
that produce antibiotics (steptomycin,
tetracyclin, erythromycin.
•Tuberculosis and leprosy are caused by
members of this group
•Abundant in soil, Streptomyces coelicolor
gives soil its characteristic smell

Front 40

Describe Cyanobacteria

Back 40

• Cyanobacteria dominate many marine and
freshwater environments.
•All are photosynthetic
•They produce much of the oxygen and nitrogen,
as well as many organic compounds, that feed
other organisms in freshwater and marine
environments.
•Some are colonial, may form mats or sheets
•Some live in association with fungi, forming
lichens

Front 41

Low-GC Gram-positive bacteria

Back 41

• Low-GC Gram-positive bacteria
(Figure 27.20) cause a variety of diseases
including anthrax, botulism, tetanus,
gangrene, and strep throat. Lactobacillus is
used to make yogurt.

Front 42

Describe Proteobacteria

Back 42

• The Proteobacteria are a major group of
bacteria. They include a wide variety of
pathogens, such as Escherichia, Salmonella,
Vibrio, Helicobacter, and many other
notable genera.
• Proteobacteria (Figure 27.21) cause
Legionnaire’s disease, cholera, dysentery,
and gonorrhea.
•Certain species can produce vinegars.
•Rhizobium can fix nitrogen.
•All Proteobacteria are gram negative.

Front 43

Describe Crenarchaeota

Back 43

• The Crenarchaeota (Figure 27.23)
are the only life-forms present in
certain extreme environments, such
as high-pressure, very hot, very cold,
or very acidic environments.

Front 44

Describe Euryarchaeota

Back 44

• The Euryarchaeota (Figure 27.24)
live in every conceivable habitat,
including high-salt, high-pH, and
low-pH environments.
•The Euryarchaeota include the
methanogens, which contribute about
2 billion tons of methane to the
atmosphere each year.