Given that the enzymes that catalyze nitrogen fixation are inhibited by oxygen, what are two ʺstrategiesʺ that nitrogen-fixing prokaryotes might use to protect these enzymes from oxygen?

1.  couple them with photosystem II (the photosystem that splits water molecules)

2.  package them in membranes that are impermeable to all gases

3.  be obligate anaerobes

4.  be strict aerobes

5.  package these enzymes in specialized cells or compartments that inhibit oxygen entry

TLS Online TPP Program

#Question id: 11108

#Unit 7. System Physiology – Animal

The most important chemical stimuli leading to increased rate and depth of breathing is:

TLS Online TPP Program

#Question id: 11109

#Unit 7. System Physiology – Animal

The gas exchange that occurs between blood and tissue cells at systemic capillaries is called:

TLS Online TPP Program

#Question id: 11110

#Unit 7. System Physiology – Animal

A very deep inspiration that ventilates all alveoli is:

TLS Online TPP Program

#Question id: 11111

#Unit 7. System Physiology – Animal

Hypoventilation dramatically increases carbonic acid concentration and involves:

TLS Online TPP Program

#Question id: 11112

#Unit 7. System Physiology – Animal

The respiratory movement representing the total amount of exchangeable air is the:

TLS Online TPP Program

#Question id: 11113

#Unit 7. System Physiology – Animal

Exchange of both oxygen and carbon dioxide through the respiratory membrane occurs by: