Related Experiment Video
Updated: May 15, 2026
10:31
A Model Membrane Platform for Reconstituting Mitochondrial Membrane Dynamics
Published on: September 2, 2020
The origin of membrane bioenergetics
1Research Department of Genetics, Evolution and Environment, University College London, Darwin Building, Gower Street, London WC1E 6BT, UK. nick.lane@ucl.ac.uk
Cell
|December 25, 2012
Summary
Chemiosmotic coupling, essential for life, may have originated from natural proton gradients in alkaline hydrothermal vents. This geochemical origin explains the early evolution of ion transporters and the divergence of life.
Area of Science:
- Biochemistry
- Astrobiology
- Origin of Life
Background:
- Ion gradients across membranes are fundamental to cellular energy harnessing, akin to the genetic code.
- Chemiosmotic coupling and sodium-hydrogen (Na+/H+) transporters are ubiquitous in modern life.
- The precise geochemical origins of these essential bioenergetic mechanisms remain largely unexplained.
Purpose of the Study:
- To propose a geochemical origin for the universality of chemiosmotic coupling and Na+/H+ transporters.
- To link early anaerobe metabolism insights with the emergence of protocells in hydrothermal vents.
- To explain the promiscuity of bioenergetic proteins and the bacterial-archaeal divergence.
Main Methods:
- Leveraging new insights into anaerobe metabolism.
- Proposing a model based on geochemical conditions in alkaline hydrothermal vents.
- Analyzing the potential role of natural proton gradients and iron sulfide (FeS) walls.
Main Results:
- Natural proton gradients across FeS walls in hydrothermal vents could have driven early carbon assimilation.
- This process may have led to the emergence of protocells within vent pores.
- Initially leaky protocell membranes evolved to become less permeable, necessitating active ion pumping (Na+).
Conclusions:
- The study hypothesizes a geochemical origin for chemiosmotic coupling and Na+/H+ transporters.
- This model accounts for the promiscuity observed in bioenergetic proteins.
- It provides a potential explanation for the deep evolutionary divergence between bacteria and archaea.
More Related Videos
Related Concept Videos
01:45Mitochondrial Membranes
A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
01:45Mitochondrial Membranes
A single mitochondrion is a bean-shaped organelle enclosed by a double-membrane system. The outer membrane of mitochondria is smooth and contains many porins - the integral membrane transporters. Porins enable free diffusion of ions and small uncharged molecules through the outer mitochondrial membrane but limit the transport of molecules larger than 5000 Daltons. Further, the outer mitochondrial membrane forms a unique structure called membrane contact sites with other subcellular organelles,...
01:22Enlargement of the Plasma Membrane
Cell division and enlargement are processes that require precise control. The control ensures that cell division cannot proceed unless the cell has grown to a specific size. A spherical, dividing cell requires an approximately 1.6X increase in its surface area to double its volume. The secretory pathway also has a significant role in cell membrane enlargement. Secretory vesicles that bud off from the Golgi apparatus and later fuse with the plasma membrane during exocytosis are a major source of...
01:15Mechanisms of Membrane-bending
The living membranes are flexible due to their fluid mosaic nature; however, their bending into different shapes is an active process regulated by specific lipids and proteins. The membrane bending can be transient as seen in vesicles or stable for a long time as in microvilli. Cells regulate the size, location, and duration of the membrane curvature.
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
01:28The Inner Mitochondrial Membrane
The inner mitochondrial membrane is the primary site of ATP synthesis. The inner membrane domain that forms a smooth layer adjacent to the outer membrane is called the inner boundary membrane. This domain contains membrane transporters that drive metabolites in and out of the mitochondria. In contrast, the inner membrane network that invaginates into the matrix space is called the cristae membrane. This domain accounts for principle mitochondrial function as it accommodates the protein...
01:44The Significance of Membrane Transport
The transport of solutes across the cell membrane is essential for metabolic processes, like maintaining cell size and volume, generating the action potential, exchanging nutrients and gases, etc. Membrane transport can be either passive or active. It can be simple diffusion, facilitated, or mediated transport aided by transport proteins such as transporters and channels.
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...
Transporters facilitate either an active or passive movement of solutes. They can allow a single-molecule transport down its...