Chp 17 Microbial Life Flashcards Preview

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Flashcards in Chp 17 Microbial Life Deck (16)
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1
Q

How are bacteria essential to human life?

A

Makes vitamins and prevents fungal growth

2
Q

What is a photoautotroph?

A

harnesses light energy to drive synth of organic compound from CO2.

3
Q

Unlike eukaryotes, prokaryotes are able to metabolize most forms of nitrogen. Whats dinitrfication?

A

conversion of NO2 or NO3 to atmospheric gas

4
Q

what is an obligate aerobe?

A

Use oxygen for cell resp. and cannot grow without it

5
Q

whats a facultative anaerobe?

A

will use oxygen if present, but can grow by fermentation

6
Q

what is an obligate anaerobe?

A

oxygen is poison.

7
Q

A bacterium living in an underground septic tank thriveds by absorbing organic compounds from decomposing wastes. what is it?

A

Chemoheterotroph

8
Q

How to prokaryotes reprouce?

A

Binary Fission: chromosome replication, splitting of cell into two daughter cells

9
Q

What is a flagella?

A

Rotating whip like structure aids in locomotion

10
Q

what is pili?

A

hair like appendage aids in clinging to surfaces. common in gram negative. longer and thinner than flagellum. used for bacterial conjugation

11
Q

What is an endospore?

A

thick protective coat used in extreme conditions. cell is metabolically inactive

12
Q

What are the characteristics of gram negative bacteria?

A

Resistant to antibiotics more than gram positive because of the outer membrane- which is unique to gram negative

13
Q

explain chemotaxis

A

organisms direct their movement according to chemicals in environment to swim towards food or away from poisons

14
Q

whats phototaxis

A

moves in response to light stimulus

15
Q

magnetotaxis?

A

organisms contain internal structures called magnetosomes which orient to earths magnetic field.

16
Q

what is the main difference between archaea and bacteria

A

nucleic acid sequence, chemical components found in cell walls and cell membranes