IB Biology HL C1.2.16 Hl Oxygen As Terminal Electron Acceptor Questions

Practise IB Biology HL 1.2.16 by applying oxygen as terminal electron acceptor concepts to exam questions.

Exam points

Identify oxygen, not ATP or reduced NAD, as the terminal electron acceptor in aerobic respiration.
Locate oxygen's direct involvement at the end of the mitochondrial electron transport chain.
Explain that oxygen combines with electrons and protons to form water without describing oxygen as the energy source.

[Maximum number: 5]

Describe the role of oxygen in aerobic cell respiration.

a. terminal/final electron acceptor

b. at the end of electron transport chain

c. oxygen also accepts protons/hydrogen ions

d. water produced/ $\frac{1}{2}\mathrm{O}_{2} + 2\text{ electrons} + 2\mathrm{H}^{+} \rightarrow \mathrm{H}_{2}\mathrm{O}$

e. helps to maintain proton gradient «across inner mitochondrial membrane by removal of protons from the stroma»

f. oxygen is highly electronegative/electrons strongly attracted to oxygen

g. avoids anaerobic respiration/buildup of lactic acid

h. allows more electrons to be delivered to the electron transport chain

OR allows NAD/FAD to be regenerated/reduced NAD/FAD converted back to NAD/FAD

i. oxygen allows maximum yield of energy «from glucose» allows complete oxidation of glucose/allows fats to be used in respiration

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IB Biology HL C1.2.16 Hl Oxygen As Terminal Electron Acceptor Questions question 1