Why can’t we bend our fingers backwards? of class 6th
Answers
Answer:
because there is no joints
Answer:
The people whose fingers bend all the way backward to touch the backs of their hands have genetic conditions that affect how their collagen functions. But “normal” and unusually stiff finger motion is also on a wide spectrum of differences affecting this important protein.
Collagen is one of the most important structural proteins in animal bodies. It is large, which makes it vulnerable to mutations that alter its shape, and it has to be processed to make it sticky after the amino acids are strung together, which provides more chances for mutations to affect its function.
Collagen molecules can be springy or not so springy. They can stick together to form rigid structures, or they can fail to stick tightly. They can link firmly to other proteins, or they can have weak binding sites for other proteins. Different tissues inside the body have different requirements and use correspondingly different collagen genes or different processing and assembly systems. Different animals also have different needs and produce collagen molecules that fit their environmental conditions. There's no single perfect collagen for every tissue in every animal.
This brings us to your fingers. Your collagen is apparently on the tighter end of the spectrum. A person with Ehlers Danlos Syndrome whose fingers bend all the way backward has collagen that is far enough toward the stretchy end of the spectrum to cause joint problems and be called an inherited disease.