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独中生物 Chapter 22 Microorganism
1.
2. Bacterial growth and reproduction
• Bacterial growth is generally
defined as the growth in the
number of bacteria within certain
time frame and conditions.
• Bacterial are too small for naked eyes
• Individual growth is not obvious
• Reproduce in a short time
3. colony菌落
• A colony is defined as a visible
mass of microorganisms all
originating from a single mother
cell
• Therefore a colony constitutes a
clone of bacteria all genetically
alike.
• The characteristics of colony - size,
color, traits, luster, dry humidity,
transparency, etc. - can be used
to preliminarily identify bacterial
species.
4. Method of bacterial reproduction
• Asexual reproduction
• Sexual reproduction
7. In binary fission how does the DNA of the daughter
cells compare to the DNA of the parent cell?
A. It is only half of the amount of DNA found in the parent.
B. It is identical.
C. It is a mix of the parent's DNA.
D. It has some similarities and some differences.
8. Bacterial asexual reproduction
• Occurs through conjugation结合/接
合
• Bacterial conjugation is the
horizontal transfer of genetic
material (plasmid) between
bacterial cells
• The genetic information
transferred is often beneficial to
the recipient.
• antibiotic resistance, xenobiotic
tolerance or the ability to use new
metabolites.
資料來源:Audesirk, T. and G. Audesirk. 1999. Biology.
Prentice Hall, p. 359.
9. 细菌的有性生殖
1. Donor cell which has F (fertility)
plasmid produces pilus.
2. Pilus attaches to recipient cell and
brings the two cells together.
3. The mobile plasmid is nicked and a
single strand of DNA is then
transferred to the recipient cell.
4. Both cells synthesize a
complementary strand to produce a
double stranded circular plasmid and
also reproduce pili; both cells are
now viable donor for the.
10. Process of mating through which two bacterial cells
transfer their DNA, a cell acts as a host while other
as recipient, process is known as
A. Transduction
B. Transformation
C. Conjugation
D. Mating
11. When bacteria are cultured in a medium,
which phase occurs first?
A. Death
B. Stationary
C. Exponential
D. Lag
13. Temperature
• Most bacteria has a optimum
temperature of 20°C - 45°C.
• Some bacteria can grow in hot
springs that are as hot as 90°C or
freezing water of about 0°C.
14. Low temperature
• Low temperature
• Slow metabolism
• Slow growth
• Frozen
• No growth
• Generally won’t die easily
16. Choose the statements below that are true an
enzyme:(choose any that apply)
1) Enzymes lower the equilibrium of a reaction.
2) The enzyme and substrate are joined with many weak bonds.
3) A single enzyme can usually catalyze many different reactions.
4) Enzymes are continually renewed by the cell as they are consumed
in reactions.
5) Enzymes lower the activation energy of a reaction.
17. pH
• Bacteria can grow in a
range of pH
• Most bacteria has an
optimum pH at 6.5~7.5.
• Unsuitable pH will affect
the
• Activity of the enzymes
• Stability of the plasma
membrane
• Solubility of substances
20. Obligate aerobic bacteria
• An obligate aerobe is an organism that
requires oxygen to grow.
• Through cellular respiration, these
organisms use oxygen to metabolise
substances, like sugars or fats, to obtain
energy.
• Oxygen serves as the terminal electron
acceptor for the electron transport chain.
• E.g. Bacillus diphtheria白喉杆菌, Rhizobium
根瘤菌
21. Obligate anaerobic bacteria
• Obligate anaerobes are microorganisms
killed by normal atmospheric
concentrations of oxygen (21%).
• Generally living in areas such as sludge
or deep soil, deep in the wound, etc.
• Use anaerobic respiration to produce
energy
• E.g. Clostridium tetani破伤风杆菌、
Clostrodium notulism肉毒杆菌
22. Facultative anaerobic
bacteria
• It can grow and reproduce in an
aerobic or anaerobic environment.
• However, it grows better when it is
aerobic, and only survives when there
is no oxygen.
• E.g. Salmonella typhi伤寒杆菌、
Escherichia coli大肠杆菌
23. Endospore芽孢/内生孢子
• An endospore is a dormant, tough, non-
reproductive structure produced by a small
number of bacteria from the Firmicute family.
• The primary function of most endospores is to
ensure the survival of a bacterium through
periods of environmental stress.
• They are therefore resistant to ultraviolet and
gamma radiation, desiccation, lysozyme,
temperature, starvation, and chemical
disinfectants.
• Endospores are commonly found in soil and
water, where they may survive for long periods
of time.
• They generally can be killed with autoclave高压
灭菌.
26. After visiting with your two nephews, you
notice some teeth marks on your arm.
Assuming there is still saliva residue present,
what is a likely first step in determining which
nephew deposited his germs on your arm?
a) wash the area
b) stain the cells where they are
c) swab the area and transfer the cells to a growth medium
d) obtain a pure culture of the cells
e) distinguish between your skin cells and the cells of interest
28. Microorganisms obtain their carbon source in
many different ways. Those that able to get the
carbon source from the organic compound are
called?
A. Autotroph
B. Chemotroph
C. Heterotroph
D. Organotroph
29. Autotrophic bacteria自养型细菌
• Synthesis complex organic molecule from
carbon dioxide
• Based on the energy source for reduction
of CO2
• Anoxygenic photosynthetic bacteria光能自养
型细菌厌氧/不產氧光合作用
• Oxygenic photosynthetic bacteria =
Photosynthesis
• Chemosynthetic bacteria化能自养型细菌
30. Anoxygenic photosynthesis
无氧光合作用
• E.g. green and sulfur bacteria绿硫细菌、紫
硫细菌.
• Absorbed solar energy with
bacteriochlorophyll细菌叶绿素
• Hydrogen sulfide (H2S) is used as a
reducing agent during photosynthesis
• Hydrogen is released and produce
sulphur
1. Energy in the form of sunlight.
2. The light dependent reactions take place when the light excites a reaction center, which donates an electron to
another molecule and starts the electron transport chain to produce ATP and NADPH.
3. Once NADPH has been produced, the Calvin cycle proceeds as in oxygenic photosynthesis, turning CO2 into
glucose.
31.
32. Oxygenic photosynthesis
• E.g. cyanobacteria蓝细菌
• Absorbed solar energy with
chlorophyll a 叶绿素a
• Plants and algae have
chlorophyll a and b
• Dinoflagelalte has chlorophyll
c
• Water is oxidized to obtain
hydrogen
• Oxygen is released as by
product
33. Two types of photosynthesis
• https://www.youtube.com/watch?v=MymzA54O-3g
36. The organism which obtain their energy from
chemicals are designated as
A. prototrophs
B. chemotrophs
C. organotrophs
D. autotrophs
37. Heterotrophic bacteria异养型细菌
• cannot produce its own food
• must ingest biomass to obtain their energy and nutrition.
• Saprophytic 腐生
• Parasitic 寄生
• Symbiotic 共生
38. Saprophytic bacteria腐生细菌
• A bacterium that absorbs nutrients from
dead animals, plants, or other organic
matter to maintain its normal life.
• Through the process of putrefaction腐化过
程.
• The act of causing to rot
• Bacteria use extracellular enzymes to
catabolise complex substances into
simple molecules.
• After updating, bacteria use intracellular
enzymes to process molecules.
39.
40. Microorganism obtained their carbon source
from the carbon dioxide are called?
A. Chemotroph
B. Autotroph
C. Heterotroph
D. Saprophyte
41. Parasitic bacteria寄生细菌
• Growing inside the host body
• Consume nutrients of the host
directly to synthesize substances
needed for its own growth
• Cause the host to become sick
or died
47. 霍乱 cholera
• Cholera is an infection of the
small intestine by some strains of
the bacterium Vibrio cholerae.
• The classic symptom is large
amounts of watery diarrhea that
lasts a few days, leading to
dehydration and electrolyte
imbalance.
• Cholera vaccines that are given by
mouth provide reasonable
protection for about six months.
• The primary treatment is oral
rehydration therapy—the
replacement of fluids with slightly
sweet and salty solutions.
48. 肺结核 tuberculosis
• Tuberculosis (TB) is a disease
caused by bacteria
Mycobacterium tuberculosis.
• The bacteria usually attack the
lungs, but they can also
damage other parts of the
body.
• TB spreads through the air
when a person with TB of the
lungs or throat coughs,
sneezes, or talks.
49. 脑膜炎 meningitis
• Meningitis is an inflammation of the
membranes (meninges) surrounding your
brain and spinal cord.
• The swelling from meningitis typically
triggers symptoms such as headache, fever
and a stiff neck.
• Meningitis can be life-threatening and
require emergency treatment.
50. 破伤风 tetanus
• Tetanus is caused by an infection with
the bacterium Clostridium tetani,
which is commonly found in soil,
saliva, dust, and manure.
• The bacteria generally enter through
a break in the skin such as a cut or
puncture wound by a contaminated
object.
• They produce toxins that interfere
with normal muscle contractions,
leading to muscle spasms.
• Recovery may take months. About ten
percent of cases prove fatal.
• Tetanus can be prevented by
immunization with the tetanus
vaccine.
51. Benefits of bacteria
• Fuel
• Archaea古细菌 manufactures methane
(natural gas)
• Food
• Cheese, yoghurt, cider
• Material recycling and
environmental purification
• Degradation, nitrogen fixation
• Medical insurance
• Synthetic drugs, synthetic insulin,
antibiotics, human symbiotic bacteria
52. Positive benefits of bacteria include which of
the following?
A. produce oxygen
B. assist in food production
C. decompose materials and help clean up the environment
D. all of these
53. Fungi
• Eukaryote
• No chlorophyll
• No roots and leaves
• Produce spores
• Growing in a humid,
warm environment
• Decomposer, can
also be parasitic
55. Structure of fungi
• Unicellular or multicellular
• Organelles (mitochondria,
endoplasmic reticulum,
vacuoles, etc.)
• Chitin cell wall
• Store food as glycogen
56. Hypha pl. hyphae菌丝
• A long, branching filamentous
structure
• Consists of one or more cells
surrounded by a tubular cell wall
• Collectively known as mycelium菌丝
体
• Each mycelium is a unit that can
sustain life independently, and
even if the mycelium is separated,
part of it can continue to grow.
57. Septumpl. septa隔膜
• In most fungi, hyphae are divided
into cells by internal cross-walls
called "septa".
• Septa are usually perforated by
pores large enough for ribosomes,
mitochondria and sometimes
nuclei to flow between cells
• Some fungi have aseptate
(nonseptate) hyphae, meaning
their hyphae are not partitioned
by septa.
58. Type of hyphae
• Vegetative hyphae: non-
pproductive
• Aerial hyphae
• Reproductive hyphae
61. Fungi nutrition
• Fungi are heterotrophic:
they rely solely on carbon
obtained from other
organisms for their
metabolism and nutrition.
• Fungi obtain nutrients in
three different ways:
• Saprotrophic
• Parasitic
• Mutualistic
62. Saprotrophic
• A saprotroph is an organism that obtains its
nutrients from non-living organic matter,
usually dead and decaying plant or animal
matter, by absorbing soluble organic
compounds.
• Saprotrophic fungi play very important roles
as recyclers in ecosystem energy flow and
biogeochemical cycles.
• Saprophytic fungi, such as shiitake (Lentinula
edodes) and oyster mushrooms (Pleurotus
ostreatus), decompose dead plant and animal
tissue by releasing enzymes from hyphal tips.
63. Parasitic and mutualistic
• As parasites, fungi live in or on
other organisms and get their
nutrients from their host.
• Parasitic fungi use enzymes to
break down living tissue, which
may causes illness in the host.
• Mutualistic fungi live harmlessly
with other living organisms.
64. How do fungi obtain their nutrients?
A. extracellular digestion
B. photosynthesis
C. predation
65. Fungi reproduction
• Fungi reproduce sexually
and/or asexually.
• In both sexual and asexual
reproduction, fungi
produce spores that
disperse from the parent
organism by either floating
on the wind or hitching a
ride on an animal.
• Spores are usually single
cells produced by
fragmentation of the
mycelium or within
specialized structures
(sporangia, gametangia,
sporophores, etc.).
66. Asexual reproduction
• Suitable humidity and plenty of food
• Form spores by fragmentation of the
mycelium
• Or budding and fission
67. Sexual reproduction
• Adverse environment
• Hyphae of two mating types
meet
• Fusion of the two cells
• Produce zygote (zygospore)
• Immediately undergo
meiosis to form spores
68. Benefits of fungi
• Nutrient cycle
• Food: bread, wine,
mushrooms
• Nutrients: Vitamin B2,
ergosterol (vitamin D)
• Antibiotics: penicillin
• Symbiosis with plants:
assisting in the absorption
of water and nutrients
74. Alga
• diatoms硅藻
• surrounded by a cell wall made
of silica (hydrated silicon dioxide)
• dinoflagellates甲藻
• Two flagellas
75. Slime mold
• When food is in short supply,
many of the single-celled
organisms will congregate
and start moving as a single
body.
• In this state they are sensitive
to airborne chemicals and
can detect food sources.
• They may form stalks that
produce fruiting bodies,
releasing countless spores.