oxygen forms can be toxic!!!!

Question 1

microbes that survive in the presence of O2 do so b/c they produce

Answer 1

enzymes that get rid of TOXIC forms of oxygen

Question 2

toxic form of oxygen (superoxide)

Answer 2

O2- picked up electron instead of being neutral

Question 3

how does superoxide occur

Answer 3

can be a byproduct of aeorbic respiration or if it uses O2 or lives in an O2 environment

Question 4

can superoxide happen even if O2 is not used

Answer 4

yes b/c oxygen is electronegative

Question 5

superoxide dismutase (SOD)

Answer 5

turns O2- + 2H+ (superoxide) into H2O2 + O2 (hydrogen peroxide + oxyegn)

deals directly with superoxide

must happen FIRST

Question 6

what two enzymes can a microbe use to deal with hydrogen peroxide

Answer 6

catalase

peroxidase

Question 7

catalase

Answer 7

2 H2O2 (hydrogen peroxide) into 2 H2O + O2 (water and oxygen)

water and oxygen

Question 8

peroxidase

Answer 8

H2O2 + 2 O2 (hydrogen peroxide) into 2 H2O (water)

water

Question 9

what are the steps microbes can take to get rid of superoxide

Answer 9

SOD and catalase OR peroxidase

Question 10

what oxygen-needs cardinal groups produce catalase & SOD

Answer 10

obligate aerobe

facultative anaerobe

aerotolerant anaerobe

Question 11

what oxygen-needs cardinal group DOES NOT produce catalase & SOD

Answer 11

obligate anaerobe

Question 12

what oxygen-needs cardinal group produces LOW catalase & SOD

Answer 12

microaerophile