BIO 210 Undergraduates Use Clay to Model Cellular Machines


Undergraduate students in Professor Goldfarb’s Molecular Cell Biology (BIO210) study about 20 different cellular machines, with the goal of understanding not only how they perform their specific tasks but also how they are integrated, organized and compartmentalized within the various organelle membranes that characterize eukaryotic cells. These tiny machines are composed of lipids, proteins, nuclei acids and carbohydrates and are powered according to the laws of thermodynamics and the principles of chemistry. Many of these apparatuses are complicated and difficult to conceptualize. A number of students attempted to gain a better grasp of the apparatuses by trying their hands at building physical models out of clay. The modeling clay was provided by the Biology Department, and students earned extra credit for well-executed projects.


Two outstanding examples are shown in the Figures. The structure shown in Fig. 1, constructed by Daniel Levine, represents a forming lipid vesicle. The budding of vesicles from the plasma membrane is mediated by a set of cage-forming proteins including the elegant clathrin triskelion. The protein dynamin twists around the neck of the nascent vesicle and promotes pinching off. The structure shown in Fig. 2A & B, constructed by Oliga Krilova, shows how the nuclear pore complex is integrated into the nuclear envelope. The nuclear pore complex facilitates the transport of proteins and RNAs between the nucleus and cytoplasm.

 

Figure 1. (Above). The formation of a clathrin-coated vesicle by Daniel Levine.

 

Figure 2A & B. (Right) Two views of a nuclear pore complex by Olga Krilova.