Wool contains a lot of protein and tastes like burnt feathers. The burnt smell of animal fur and its products, such as wool clothing and silk clothing, can be used to distinguish authenticity. The smell of burning paper represents plant fibers, such as wood, cotton, hemp and other plants and their products.
Protein is the material basis of life, an organic macromolecule, a basic organic substance that constitutes cells, and the main undertaker of life activities. There is no life without protein. Amino acids are the basic components of protein. It is a substance closely related to life and various forms of life activities. Protein participates in every cell and all important parts of the body.
Feathers are keratinized products from epidermal cells of birds. Covered on the body surface, it is light and tough, slightly elastic and waterproof, and has the functions of protecting the body, keeping warm and flying. In addition, feathers can be made into badminton, feather pen, feather powder and other items after processing, which has high economic value.
The main drafting units of the national standard of Down: China Chamber of Commerce for Import and Export of Food, Native Animals and Livestock, Liuqiao Group Co., Ltd. and China Down Industry Association. Bird feathers are light and wear-resistant, and they are poor conductors of heat. Flying feathers and tail feathers are of great significance to flight. Birds often bathe their feathers, shake off the dust between them, comb them with their mouths, and peck the fat secreted by fat glands at the tail to smear them all over their bodies.
Structure of positive feather:
1, quill-located in the central axis and hollow, also known as "quill" and "quill". There are some light foam-like substances hidden in the tube of feather shaft, which makes it easy for birds to fly. This special structure also makes the wings of birds not break when flying.
2, feather root-the lower part of the feather shaft, also known as "feather handle", hollow, translucent, deep into the skin. Feather shaft-there is a shallow groove running through its ventral surface at the upper part of the feather shaft, and finally there is a small hole at the joint between the feather root and the feather shaft, which is called "upper umbilicus".
3. The lower umbilicus-the small hole at the end of the feather root, which contains dermal papillae, is the growth place of new feather pulp. Ways to provide feather nutrition to papilla.
4. Upper umbilicus-a small hole at the top of the feather root, which gives birth to a cluster of underdeveloped small feathers under the upper umbilicus, called secondary feathers (the secondary feathers of ordinary birds are underdeveloped, and the secondary feathers of emus and turkeys are developed). Feather-located on both sides of the feather axis, composed of feather branches. There are many parallel feather branches obliquely on both sides of each feather branch. There are hooks and grooves on the feather branches, and the hooks and grooves on adjacent feather branches hook each other to form a feather sheet.