Question

What term did Peter D. Mitchell use to describe his proposal in 1961 regarding chemiosmosis?

a. Hypothesis
b. Theory
c. Postulate
d. Concept

According to Mitchell's proposal, what was the primary question he aimed to address regarding oxidative phosphorylation?
a. Identification of the compound X~P
b. Mechanism of substrate-level phosphorylation
c. Role of ATP synthase enzyme
d. Use of free energy released from the electron transport chain

What term did Mitchell use in the original 1961 Nature paper to describe his idea of chemiosmosis?
a. Chemiosmotic postulate
b. Chemiosmotic theory
c. Electrochemical hypothesis
d. Oxidative phosphorylation concept

What experimental evidence contributed to the acceptance of Mitchell's hypothesis of chemiosmosis?
a. Acid-bath experiment of Uribe and Jagendorf
b. Substrate-level phosphorylation study
c. Chloroplast electron transport chain analysis
d. Proton loading in the dark

How does the article argue for the current status of Mitchell's proposal on chemiosmosis?
a. It emphasizes the speculative nature of the hypothesis.
b. It suggests that Mitchell's proposal remains untested.
c. It considers chemiosmosis as a scientific fact.
d. It questions the experimental validity of chemiosmotic theory.

How do dictionaries like Merriam–Webster distinguish between a hypothesis and a theory?
a. A hypothesis is an assumption formed after research, while a theory explains observed data.
b. A hypothesis is a tentative explanation before any research, and a theory is a proven principle.
c. Both terms are used interchangeably in the context of scientific proposals.
d. A hypothesis is more likely to be true than a theory based on experimental rigor.

Answer 1

1. Peter D. Mitchell used the term 'Postulate' to describe his proposal in 1961 regarding chemiosmosis.

2. Mitchell aimed to address the Role of ATP synthase enzyme in his proposal on oxidative phosphorylation.

3. Mitchell used the term 'Postulate' in the original 1961 Nature paper to describe his idea of chemiosmosis.

4. The acid-bath experiment of Uribe and Jagendorf contributed to the acceptance of Mitchell's hypothesis of chemiosmosis.

5. Chemiosmosis is considered as a scientific fact due to extensive experimental evidence and research support.

6. A hypothesis is a tentative explanation before any research, and a theory is a proven principle, according to dictionaries like Merriam–Webster.

Step-by-step explanation:

Peter D. Mitchell introduced the concept of chemiosmosis in 1961, referring to it as a 'Postulate' rather than a hypothesis, theory, or concept. He postulated that an electrochemical gradient of protons across a membrane powers ATP synthesis. This proposal challenged existing ideas about oxidative phosphorylation.

The primary question Mitchell aimed to address in his proposal was the role of the ATP synthase enzyme. He proposed that ATP synthesis occurred due to the flow of protons through a membrane-bound ATP synthase enzyme, leading to the synthesis of ATP from ADP and inorganic phosphate. This notion was novel at the time and sought to explain the mechanism underlying ATP production in biological systems.

Experimental evidence, such as the acid-bath experiment conducted by Uribe and Jagendorf, supported Mitchell's postulate. Their experiment demonstrated the role of a proton gradient in ATP synthesis within chloroplasts. This and other experimental findings validated Mitchell's idea of chemiosmosis, contributing significantly to its acceptance in the scientific community.

Considering the current status of Mitchell's proposal, chemiosmosis is now considered a scientific fact. Over time, extensive experimental evidence and further research have solidified Mitchell's postulate into an established concept, explaining how ATP synthesis occurs in various cellular processes. Mitchell's contribution revolutionized the understanding of bioenergetics, and chemiosmosis remains a foundational concept in biology and biochemistry