Here's a breakdown:

* Actin and myosin are the main contractile proteins in muscle fibers. They interact with each other to create the sliding filament mechanism that allows muscles to contract and relax.

* Myoglobin is another important protein found in muscle cells. It stores oxygen for use during muscle contraction.

* Creatine phosphate is a high-energy molecule that provides energy for muscle contraction.

* Glycogen is a stored form of glucose that can be used for energy by muscle cells.

* Water makes up a large percentage of muscle tissue.

So, while you might hear about "muscle" as a singular thing, it's really a complex arrangement of many different molecules working together to create movement.