packed together in the cells, the harder it is to cut across them So the meat of older, well exercised animals is tougher than the meat of young animals Connective Tissue Connective tissue is the physical harness for all the other tissues in the body, muscle included It connects individual cells and tissues to each other, thus organizing and coordinating their actions Invisibly thin layers of connective tissue surround each muscle fiber and hold neighboring fibers together in bundles, then merge to form the large, silver-white sheets that organize fiber bundles into muscles, and the translucent tendons that join muscles to bones When the fibers contract, they pull this harness of connective tissue with them, and the harness pulls the bones The more force that a muscle exerts, the more connective tissue it needs for reinforcement, and the stronger the tissue needs to be So as an animal’s growth and exercise bulk up the muscle fibers, they also bulk up and toughen the connective tissue Connective tissue includes some living cells, but consists mainly of molecules that the cells secrete into the large spaces between them The most important of these molecules for the cook are the protein filaments that run throughout the tissue and reinforce it One, a protein called elastin for its stretchiness, is the main component of blood vessel walls and ligaments, and is especially tough; its crosslinks cannot be broken by the heat of cooking Fortunately there isn’t much of it in most muscle tissue The major connective-tissue filament is the protein called collagen, which makes up about a third of all the protein in the animal body, and is concentrated in skin, tendons, and bones The name comes from the Greek for “glue producing,” because when it’s heated in water, solid, tough collagen partly dissolves into sticky gelatin (p 597) So unlike the ... The major connective-tissue filament is the protein called collagen, which makes up about a third of all the protein in the animal body, and is concentrated in skin, tendons, and bones The name comes from the Greek for... the cells secrete into the large spaces between them The most important of these molecules for the cook are the protein filaments that run throughout the tissue and reinforce it One, a protein called elastin for its stretchiness, is the main component of blood vessel walls and. .. bulk up the muscle fibers, they also bulk up and toughen the connective tissue Connective tissue includes some living cells, but consists mainly of molecules that the cells secrete into the large spaces between