Water forms droplets on the surface of a leaf but it spreads and completely wets the skin of a snail. Why does water behave so differently on the two surfaces? In this video, we introduce the fundamental concepts of surface tension, contact angle and the difference between hydrophobic and hydrophilic materials. Also, we illustrate with examples how the physics of wetting helps understand biological features in cells!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to the Physics of Wetting appeared first on RTG 3120 Biomolecular Condensates.

Get ready to dive into the Free Energy!

Cells can be described as systems made of different phases. For instance, biomolecular condensates are dense droplets of proteins that coexist with the rest of the cytoplasm. Thermodynamics is a helpful theoretical framework to understand phases in cells. In this video, we explain the concept of Free Energy of a mixture and we see how can we predict the equilibrium state of the system from the Free Energy.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post Diving into the Free Energy: Part 1 appeared first on RTG 3120 Biomolecular Condensates.

Get ready to dive into the Free Energy!

If we want to understand phases in cells we need to talk about the Free Energy of a thermodynamic system. This is the second part of the video “Diving into the Free Energy”. In this video, we will understand how thermodynamic mixtures reach equilibrium by minimising the Free Energy. We will see that asking if a mixture will phase-separate or not is the same as asking what is the minimum energy allowed for the mixture. Not only that, but we will also show how the Binodal line on the Phase Diagram directly emerges from the Free Energy!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post Diving into the Free Energy: Part 2 appeared first on RTG 3120 Biomolecular Condensates.

The Earth, which once was a messy ball of melted rock, is now teeming with complex living creatures extraordinarily adapted to their ecosystem. But the second law of thermodynamics tells us that systems spontaneously tend towards disorder and structures states, just like milk tends to mix with coffee. Then, where does complexity come from? Watch this quick intro to Complexity to understand how Nature creates complexity!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to Complexity appeared first on RTG 3120 Biomolecular Condensates.

Have you ever seen a movie backwards in time? How did you figure out that the time was flowing backwards? This could seem a silly question. But think about it. It strongly depends on the what process the movie was showing! If you see many pieces of broken glass coming together from different directions to build a bottle that moves against gravity, you’ll immediately know that the movie is reversed. You know that because breaking a bottle is a very irreversible process. But how would you know it if the movie shows a pendulum? Or two billiard balls colliding? Or a planet orbiting a star? The way we guess the arrow of time on irreversible processes has to do with the Second Law of Thermodynamics! Watch this quick intro to Irreversibility!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to Irreversibility appeared first on RTG 3120 Biomolecular Condensates.

Phase Diagrams are graphic representations that help understand many physical systems such as magnets and pure substances like water. These diagrams also help us understand how dense droplets of biomolecules, called Biomolecular Condensates, form inside cells. Phase Diagrams predict under which conditions these condensates can form and also what will be their molecular concentration. Watch this quick intro to learn more! References: -Video C. Elegans: Fritsch, Diaz-Delgadillo, Adame-Arana et al., PNAS (2021) https://www.pnas.org/doi/10.1073/pnas… -Multicomponent Phase Diagram: Bauerman, Laha, McCall, and Weber JACS (2022) https://pubs.acs.org/doi/pdf/10.1021/…

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to the Phase Diagram appeared first on RTG 3120 Biomolecular Condensates.

Have you ever seen a tepid cup of coffee getting hot? Or a pile of sand grains organizing themselves into a sand castle? It would be strange, right? But why? The reason is behind one of the most fundamental and general laws of physics: The Second Law of Thermodynamics.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to Entropy appeared first on RTG 3120 Biomolecular Condensates.

Have you ever seen a tepid cup of coffee getting hot? Or a pile of sand grains organizing themselves into a sand castle? It would be strange, right? But why? The reason is behind one of the most fundamental and general laws of physics: The Second Law of Thermodynamics.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to the Second Law of Thermodynamics appeared first on RTG 3120 Biomolecular Condensates.

Ink and water mix but oil and water don’t. We all know this. But why? Mixing and demixing are relevant processes for many different systems: from the air, you breathe to metallic alloys on your car wheels, and to the smoothie on your breakfast. Recent research shows that these processes also take place inside cells! Biomolecules can be mixed with the liquid interior of the cell. Sometimes these molecules demix and form droplets like oil in water. A mechanism to assemble these droplets is assembled through a process called Phase Separation. This video is a short introduction to the physics of Phase Separation.

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to Phase Separation appeared first on RTG 3120 Biomolecular Condensates.

In schoolbooks, cells are generally pictured as a membrane bubble full of smaller compartments also wrapped by a membrane. In reality, things differ from this simple picture. There are many compartments that are not bound by a membrane. Learn what they are and their amazing properties in this 2 minute video!

Prepared by Mariona Esquerda Ciutat from the Hyman and Jülicher labs in Dresden.

The post A quick intro to Biomolecular Condensates appeared first on RTG 3120 Biomolecular Condensates.