Anaerobic Conditions and the Origin of Glycolysis
Every living cell must pay for its existence in energy, and the currency it spends is ATP. But the machinery that mints this currency is far older than the oxygen-rich atmosphere we now take for granted. Long before photosynthesis flooded the planet with oxygen, the first cells on Earth lived in an atmosphere that lacked oxygen entirely — and they solved the energy problem with a chemistry that required none.
This quiz follows Lesson 5 of Respiration in Plants and tests your grasp of:
- Cells and organisms living where oxygen may or may not be available
- The first cells on Earth in an oxygen-lacking atmosphere
- Facultative versus obligate anaerobes
- The enzymatic machinery that partially oxidises glucose without oxygen
- Glycolysis as the breakdown of glucose to pyruvic acid
Read each question carefully. All answers can be reasoned from the lesson itself — no outside knowledge is required.
Q1. According to the lesson, the first cells on this planet lived in an atmosphere that:
The lesson states there are sufficient reasons to believe that the first cells on this planet lived in an atmosphere that lacked oxygen.
Q2. Organisms that are adapted to anaerobic conditions and for which the requirement for anaerobic conditions is a strict necessity are called:
The lesson distinguishes facultative anaerobes from those in which the requirement for anaerobic conditions is obligate, i.e. a strict requirement.
Q3. Which statement best describes facultative anaerobes as presented in the lesson?
Facultative anaerobes are organisms that can tolerate conditions where oxygen may or may not be available, unlike obligate anaerobes.
Q4. The breakdown of glucose to pyruvic acid is called:
The lesson explicitly defines the breakdown of glucose to pyruvic acid as glycolysis.
Q5. According to the lesson, all living organisms retain the enzymatic machinery to:
The lesson states that all living organisms retain the enzymatic machinery to partially oxidise glucose without the help of oxygen.
Q6. In anaerobic organisms, glycolysis is described in the lesson as:
The lesson states that in anaerobic organisms glycolysis is the only process in respiration.
Q7. The scheme of glycolysis was given by Embden, Meyerhof and Parnas and is therefore often referred to as the:
The lesson notes that the scheme of glycolysis given by Embden, Meyerhof and Parnas is often referred to as the EMP pathway.
Q8. Where in the cell does glycolysis occur?
The lesson states that glycolysis occurs in the cytoplasm of the cell.
Q9. In glycolysis, one molecule of glucose undergoes partial oxidation to form:
The lesson states that in glycolysis glucose undergoes partial oxidation to form two molecules of pyruvic acid.
Q10. The term glycolysis originates from the Greek words:
The lesson explains that glycolysis comes from the Greek words glycos (sugar) and lysis (splitting).
Q11. Which of the following is given in the lesson as an example of a situation where oxygen may not be available to a cell?
The lesson lists a germinating seed buried in waterlogged soil among situations where oxygen supply falters while energy demand continues.
Q12. The complete combustion of glucose requires oxygen and yields energy, most of which is given out as:
The lesson states that the complete combustion of glucose yields energy, most of which is given out as heat.
Q13. Why does the plant cell oxidise glucose in several small steps rather than in one step?
The lesson explains that oxidising glucose in several small steps allows some steps to be just large enough for the released energy to be coupled to ATP synthesis.
Q14. In plants, the glucose used in glycolysis is derived from:
The lesson states that in plants glucose is derived from sucrose, the end product of photosynthesis, or from storage.
Q15. Which statement about glycolysis is correct according to the lesson?
The lesson states that glycolysis is present in all living organisms and occurs in the cytoplasm.