Why in the News?
A new Nature Physics study suggests that warm volcanic rock surfaces may have concentrated organic molecules in watery cracks, triggering life-like chemistry—offering a clue to how protocells formed without membranes before life began.
What are Protocells?
- Overview: Protocells are primitive, cell-like bubbles believed to be early precursors of real biological cells. They were not fully alive but provided a space for early chemical interactions.
- Lack of Complexity: These structures lacked complex parts like organelles or DNA systems but could hold important molecules like RNA and amino acids together.
- Membrane Role: Protocells often formed simple membranes or boundaries, which allowed molecules to stay enclosed and interact more easily—helping early reactions like protein synthesis happen.
- Importance: Although not living, they offered a model of how basic chemistry could evolve into biology, bridging the gap between non-living and living systems.
History of Formation of Protocells:
- Early Earth Conditions: Over 3.5 billion years ago, Earth’s surface had warm water pools and volcanic cracks filled with organic molecules made by natural processes like lightning.
- Compartmentalization: The first step toward life was concentrating useful molecules in one place, so they could start reacting—this led to the idea of bubble-like protocells.
- Old Theories: In the 1920s, Oparin and Haldane proposed that life began in a “primordial soup” with spontaneous chemical reactions in early Earth’s oceans.
- Modern Insights: Newer research suggests cracks in volcanic rock or hydrothermal vents created temperature gradients and water flows that helped form protocells—no complex membranes were needed.
Key Findings in the 2025 Study:
- Lab Setup: Scientists created a 170-micrometre chamber with a warm top (40°C) and cool bottom (27°C), simulating early Earth rock cracks.
- DNA Test: They added DNA and a protein-making kit (PURExpress). Only in the warm-cool chamber did the DNA make green fluorescent protein (GFP), showing real protein synthesis.
- Molecule Gathering: Essential items like DNA, magnesium, and phosphate ions gathered more at the bottom—up to 70 times more concentrated than at the top.
- Cell-Like Behavior: Even without a membrane, the system kept useful molecules inside while letting waste escape, mimicking real cell selectivity.
- Big Implication: This experiment supports the idea that life could start in simple natural environments using just heat, flow, and basic chemicals—long before full cells appeared.
| [UPSC 2018] Consider the following statements:
1. The Earth’s magnetic field has reversed every few hundred thousand years.
2. When the Earth was created more than 4000 million years ago, there was 54% oxygen and no carbon dioxide.
3. When living organisms originated, they modified the early atmosphere of the Earth. Which of the statements given above is/are correct?
Options: (a) 1 only (b) 2 and 3 only (c) 1 and 3 only * (d) 1, 2 and 3 |
