Question

Which organic molecules were formed in the Miller-Urey experiment?

• A. Nucleotides
• B. Amino acids
• C. Polysaccharides
• D. Vitamins

Hint:

Remember Miller-Urey = Amino Acids. This experiment is a cornerstone of abiogenesis research, demonstrating that fundamental organic building blocks of life could have formed under primitive Earth conditions.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question asks to identify the primary type of organic molecules that were synthesized in the famous Miller-Urey experiment.

Step 3: Detailed Explanation:
Miller-Urey Experiment (1952): Stanley Miller and Harold Urey conducted an experiment to simulate the conditions of early Earth's atmosphere and test the hypothesis that organic compounds could have spontaneously formed from inorganic precursors.
Setup: They used a closed system containing water, methane ($CH_4$), ammonia ($NH_3$), and hydrogen gas ($H_2$) to represent the primitive atmosphere. Electrical sparks simulated lightning, and heating/cooling cycles simulated precipitation.
Results: After about a week, they analyzed the contents of the flask and found that various organic compounds had formed. The most significant finding was the presence of several amino acids (e.g., glycine, alanine, aspartic acid), which are the building blocks of proteins. They also detected other simple organic molecules.
Option Analysis:
- (A) Nucleotides: More complex molecules, not the primary output.
- (B) Amino acids: This was the main discovery.
- (C) Polysaccharides: These are complex polymers of sugars, not directly formed.
- (D) Vitamins: Complex organic molecules, not formed.
Therefore, amino acids were the organic molecules formed.

Step 4: Final Answer:
Amino acids were formed in the Miller-Urey experiment.