Question

1. what is the location of ETS during aerobic respiration

2. in cellular respiration in which of the phases is most of the ATP produced

3. where does ets occur?

4. what is the primary role of oxygen in cellular respiration?

5. in addition to ATP produced, what are the end product of glycolysis?

6. in what phase of respiration is CO2 formed?

Answer 1

Ans. #1. Electron transport system (ETS) is located in the inner mitochondria membrane (mitochondria). The ETC complexes (complex I - IV) and electron carriers are associated with inner mitochondrial membrane whereas the reaction compartments include the matrix and inter membrane space.

#2. Most ATPs are produced during Oxidative phosphorylation, around 28 ATP out of total 30 ATP from 1 glucose molecule. Oxidative phosphorylation synthesizes ATP by pumping protons from intermembrane space to mitochondria matrix via ATP synthase.

#3. The process of Electron transport system (ETS) occurs in mitochondria – involves inner mitochondria membrane (to which ETC complexes and electron carriers are associated), matrix and the intermembrane space.

#4. O₂ serves as the terminal electron acceptor in cellular respiration.

#5. Overall reaction of Glycolysis is –

Glucose + 2ATP + 2NAD⁺ + 4ADP + 4Pi à 2 Pyruvate + 2NADH + 2H⁺ + 4ATP

So, in addition to ATP, pyruvate and NADH are also the end products of glycolysis.

#6. Overall reaction of citric acid cycle-

Acetyl-CoA + 3 NAD⁺ + FAD + GDP + Pi à CoA + 3 NADH + FADH₂ + GTP + 2 CO₂

# CO₂ is produced only during citric acid cycle.