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Biology 2 > Bacteria and Viruses (help) > Flashcards

Bacteria and Viruses (help) Flashcards

1
Q

What are prokaryotes?

A

Unicellular organisms that lack a nucleus.

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2
Q

Do prokaryotes have DNA?

A

Yes, but it floats freely around the cell

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3
Q

What are the 2 kingdoms of prokaryotes?

A

Bacteria and Archaea

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4
Q

Are archaea and bacteria prokaryotes?

A

No, they are eukaryotes

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5
Q

Which is larger: bacteria or archaebacteria?

A

Bacteria

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6
Q

TRUE OR FALSE: Bacteria includes a wide variety of organisms

A

true

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7
Q

T or F: Bacteria only lives in human beings

A

False: Bacteria lives almost everywhere, including humans

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8
Q

What is a bacteria usually surrounded by?

A

Usually surround by a cell wall that protects the cell from injury and determines its shape

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9
Q

What do bacteria cells contain?

A

They contain peptidoglycan

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10
Q

What is peptidoglycan?

A

Its a polymer of sugars and amino acids that surrounds the cell membrane. Peptidoglycan wall makes the cell especially resistant to damage

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11
Q

How do bacteria move around?

A

They move around either using a flagella, cilia, or secreting liquid

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12
Q

Do archaea have peptidoglycan?

A

No

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13
Q

T or F: Archaea live in extremely harsh environments

A

True

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14
Q

What are the 3 shapes that a bacteria can have? List the describe.

A
  1. Bacilli (rod-shaped)
  2. Cocci (spherical shape)
  3. Spirilla (spiral/corkscrew shape)
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15
Q

Do prokaryotes need a supply of chemical energy?

A

Yes

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16
Q

What are the different ways prokaryotes obtain energy? List and describe

A
  1. Heterotroph - Take in organic molecules from environment or other organisms to use as both energy and carbon supply
  2. Photohetetroph - Like basic heterotrophs, but also use light energy
  3. Photoautroph - Use light energy to convert CO2 into carbon compounds
  4. Chemoautotroph - use energy released by chemical reactions involving ammonia, etc.
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17
Q

What is binary fission?

A

This is how prokaryotes reproduce. It’s an asexual process which produces genetically identical.

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18
Q

What is endospore?

A

A thick internal wall that encloses the DNA and a portion of the cytoplasm. An endospore forms when growth conditions are unfavorable. Endospores can remain dormant for years.

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19
Q

What does endospore do for the cell?

A

It makes it possible for some prokaryotes to survive very hard conditions

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20
Q

What are the 2 ways prokaryotic populations can evolve?

A
  1. mutation
  2. conjugation
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21
Q

Describe the mutation process for a prokaryote

A

In prokaryotes, mutations are inherited by daughter cells produced by binary fission. But first a random change occurs in the DNA.

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22
Q

Describe the conjugation process for prokaryotes

A

Conjugation is a way for prokaryotes to exchange genetic info. Two cells build a small bridge and plasmids carry pieces of genetic information between the cells. This creates some genetic diversity.

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23
Q

Why are prokaryotes important to life?

A

Prokaryotes are essential in maintaining every aspect of the ecological balance of the living world. Some species also have specific uses in the human industry.

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24
Q

Describe prokaryotes in decomposition

A

Prokaryotes assist in the breakdown of dead organisms. This supplies raw materials to other organisms that need them to survive. It also maintains equilibrium in the environment.

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25
Q

Describe prokaryotes as producers:

A

Photosynthetic prokaryotes are among the most important producers on the planet. This species produces A LOT of stuff.

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26
Q

How are prokaryotes important to food chains?

A

Food chains are dependent on prokaryotes as producers of food and biomass.

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27
Q

What organism does nitrogen fixation?

A

Prokaryotes

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28
Q

What is nitrogen fixation?

A

Converting nitrogen gas into ammonia. Ammonia can then be converted to nitrates that plants use.
All organisms need nitrogen to make proteins and molecules!

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29
Q

How do humans use proteins?

A

Prokaryotes are used in the production of foods and commerical products (for example: yogurt, synthesizing drugs). Some bacteria are also used to remove petroleum and remove human waste or poison from water.

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30
Q

What is a virus?

A

A nonliving particle made of proteins, nucleic acids, and sometimes lipids.

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31
Q

What are viruses made of?

A

Proteins, nucleic acids, and sometimes lipids

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32
Q

Are viruses particles or cells?

A

Particles

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33
Q

Are viruses alive?

A

No

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34
Q

Are viruses cells?

A

No

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35
Q

What is the structure of viruses?

A
  • Very small!!
  • Have capsids
  • Have proteins on their surface membrane (this is alternative to capsid)
  • DNA or RNA
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36
Q

What is a capsid?

A

A protein coat surrounding a virus. Used to trick the host cell into taking in the virus, or in letting it inject its DNA into the host cell

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37
Q

Why do viruses infect very specific types of cells? Can viruses infect any organism?

A

While viruses can infect lots of organisms, they are very selective because because the virus must bind precisely to proteins on the host cell surface and not every cell will match that

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38
Q

What is a bacteriophage?

A

A virus that infects bacteria

39
Q

What are the two ways viruses reproduce?

A

Lytic cycle or lysogenic cycle

40
Q

What must viruses do to reproduce?

A

Viruses must infect a host cell to reproduce; they can’t reproduce on their own

41
Q

Describe the lytic cycle step by step:

A
  1. Capsid binds to cell
  2. Virus enters a bacterial cell by injecting its DNA into the cell
  3. The viral mRNA is translated into viral proteins that act like a molecular wrecking crew, chopping up the cell’s DNA
  4. Now that the virus is in control of the cell, the virus now forced the host cell to make thousands of copies of the new virus particles
  5. The cell bursts in a process called lyse or lyses.
  6. Hundreds of new virus particles are released to go and infect other cells
42
Q

What is lyses?

A

A process where the host cell bursts in the lytic cycle

43
Q

Describe the lysogenic cycle step by step

A
  1. A virus attaches with the capsid and injects its DNA
  2. A host cell is not immediately taken over! Instead, the viral nucleic acid is inserted into the host cell’s DNA, where it is copied along with the host DNA WITHOUT DAMAGING THE HOST.
  3. Viral DNA multiplies as the host cells multiply.
  4. Thus, each generation of daughter cells is derived from the original host cell that was infected.
44
Q

Does the lysogenic cycle affect the host cell while the virus is dormant?

A

No, it doesn’t

45
Q

What is a prophage?

A

Bacteriophage DNA that becomes embedded in the bacterial host’s DNA. The prophage may remain part of the DNA of the host cell for many generations.

46
Q

What can cause a prophage to become active?

A

Influences from the environment, such as radiation, heat, or chemicals.

47
Q

What happens after a prophage becomes active?

A

It then removes itself from the DNA and directs the synthesis of virus particles

48
Q

Describe the attack process of the common cold virus

A
  1. Capsid settles on the cell and is brought inside
  2. Viral protein makes many copies of the viral RNA
  3. Host cell’s ribosomes mistake the viral RNA for the host’s own mRNA - translate it into viral proteins
  4. Lyse happens
49
Q

What is a retrovirus?

A

The genetic info of a retrovirus is copied from RNA to DNA instead of DNA to RNA

50
Q

Is HIV a retrovirus?

A

Yes

51
Q

Describe how HIV (like retroviruses in general) infect and affect a host cell

A

When a retrovirus infects a cell, it makes a DNA copy of its RNA, which inserts into the DNA of the host cell. Retrovirus infections are similar to lysogenic infections - the viral DNA in this case can remain inactive fora long time. But once activated, it begins to destroy the very system of the body that would normally fight infection.

52
Q

What type of cells does HIV attack?

A

White blood cells (the ones that are meant to protect your body from diseases)

53
Q

Do viruses need to obtain and use energy like prokaryotes do?

A

No

54
Q

What are 3 types of archaebacteria?

A
  1. Methanogens
  2. Extreme halophiles
  3. Thermoacidophiles
55
Q

Describe Methanogens

A

Archaea kindgom; harvest energy by making methane gas; oxygen is poison to them. Present in swamps and intestines

56
Q

Descripe extreme halophiles

A

Archaea kingdom; live in high salt concentrations; use salt to generate ATP

57
Q

Describe thermoacidophiles

A

Archaea kingdom; live in environments of high acidity and high temp

58
Q

T or F: There are 2 types of cell walls found in eubacteria

A

True

59
Q

Describe the heterotroph bacteria process

A

Heterotrophs take in organic molecules for energy and a supply of carbon

60
Q

Describe chemoheterotrophs

A

Eat molecules

61
Q

Describe photoheterotrophs

A

Synthesize for energy but take in organic compounds as a carbon source

62
Q

Describe autotrophic process for bacteria

A

Make food from inorganic sources

63
Q

Describe photoautotrophs

A

Use light energy to convert CO2 and H2O go make organic compounds and oxygen

64
Q

Describe chemoautotrophs

A

Use CO2 to make organic molecules but don’t use light

65
Q

Describe gram positive bacteria

A

They have thicker peptidoglycan in their cell walls, which allows them to stain purple

66
Q

What is gram staining used for?

A

Its used to identify bacteria

67
Q

What do gram positive and gram negative bacteria differ in?

A
  • Differ in susceptibles to antibacterial drugs
  • Produce different toxic materials
  • React differently to disinfectants
68
Q

What are the 3 different bacteria categories based on oxygen use?

A
  1. Obligate anaerobes
    2.Facultative anaerobes
  2. Obligate aerobes
69
Q

Describe obligate anaerobes

A

Can’t survive without presence of oxygen

70
Q

Describe facultative anaerobes

A

Can live with or without oxygen

71
Q

Describe obligate anaerobes

A

Cannot survive without oxygen

72
Q

Is endospore a form of reproduction for bacteria?

A

NO!!

73
Q

T or F: A single chromosome is replicated in binary fission

A

True

74
Q

list the different areas where bacteria is important

A
  1. Decomposers
  2. Nitrogen fixation
  3. Producers of food and beverages
  4. Digesting petroleum and cleaning up oil spills
  5. Synthesize drugs and chemicals
75
Q

Can viruses make their own proteins? Why or why not?

A

No; they don’t have the means to make proteins or other reproductive stuff

76
Q

What are the different genetic info a virus may contain?

A
  1. double-stranded DNA
  2. Single-stranded DNA
  3. Single stranded RNA
77
Q

Will antibiotics work on viruses?

A

No

78
Q

What are pathogens? Describe.

A

Disease causing agents. Although pathogens can come from any taxonomic group, bacteria and viruses are among the most common. All currently known prokaryotic pathogens are bacteria.

79
Q

Who was Louis Pasteur and what did he do?

A

French chemist 1st to show cinvicingly that bacteria cause disease

80
Q

How do bacteria cause disease?

A

By destroying living cells or by releasing chemicals that upset homeostasis. Some bacteria may affect tissue directly, while others release toxins.

81
Q

What is an example of a bacterium that damages host tissues?

A

Tuberculosis bacterium

82
Q

What is a bacterium that releases toxins (example)?

A

The species that caquses diphteria, and the species responsible for botulism.

83
Q

What are the ways to control bacteria?

A
  1. Physical removal
  2. Disinfectants
  3. Food Storage
  4. Food processsing
  5. Sterilization
84
Q

What is a way to prevent bacterial diseases (and viruses)?

A

Vaccines

85
Q

How does a vaccine kill viruses/bacteria?

A

Prompts the body to produce immunity to a specific disease

86
Q

What do antibiotics do? What can you treat with antibiotics?

A

They disrupt proteins or cell processes that are specific to bacterial cells. THIS DOESN’T HARM HOST CELLS! Antibiotics can be used on bacteria

87
Q

How do viruses cause disease?

A

By directly destroying living cells or by affecting cellular processes in ways that upset homeostasis

88
Q

What are 2 ways to prevent virus infection?

A

Good hygiene and vaccines

89
Q

What is an emerging disease?

A

An unknown disease that suddenly appears in a population for the first time, or a well-known disease that suddenly becomes harder to control

90
Q

What makes emerging diseases even more of a threat?

A

Change in commerce and lifestyle

91
Q

Why are the pathogens that cause emerging diseases to threatening to humans?

A

Human populations have little to no resistance to these diseases, and the methods of control haven’t been developed yet

92
Q

What are superbugs and how have they developed?

A

Superbugs are bacteria that have grown resistant to most antibiotics through natural selection processes.

93
Q

What is a dangerous form of a superbug?

A

MRSA

94
Q

What are prions? Describe the process

A

Prions stands for “protein infectious particles”. Humans can become infected with them. Prions are formed when a protein called PrP is improperly folded. An accumulation of prions can damage nerve cells.

Biology 2 (10 decks)

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