【英语时差8,16】奇特的蛋白(上)(在线收听) |
Have you ever wondered how heating an egg white turns that uncooked clear goo into an opaque gel? Well, that transparent goo is made of mostly water and proteins. Each protein is a long strand of amino acids that you can think of as a string of green and red Christmas lights. The green lights are hydrophilic amino acids, which attract water, and the red lights are hydrophobic amino acids, which hate water. Each protein is coiled up in a big clump so that most of the water-loving green lights point outwards from the mass while most of the water-hating red lights point towards the inside to keep dry. These coiled up proteins float around in small clumps allowing light to easily pass through the goo and provide little structure, so the goo is clear and liquidy.
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