Two types: actin (thin filament) & myosin (thick filament)
Myofibril ~or~ Myofibril.
Myofibrils are composed of proteins such as actin, myosin, titin. These proteins are organized into thin filaments and thick filaments, which repeat along the length of the myofibril in sections called sarcomeres.
Actin and Myosin. A conglomeration of actin fibrils and myosin filaments form a myofibril body called a sarcomere.
The sarcomere is the contractile unit. It is the space between two Z discs that contains one group of myosin fillaments and two groups of actin fillaments, one group on each end of the myosin fillaments. Z discs join sarcomeres together end-to-end to form myofibrils. A group of myofibrils surrounded by the sarcolema makes up a muscle fiber.
Muscles contain certain proteins called contractile proteins which enable it to contract and relax to bring about movements.
Proteins have various functions: enzymes, antibodies, hormones, structural, contractile, transport and storage. Proteins are produced through a process called translation from DNA segments.
muscle contain special proteins called contractile proteins, they contract and relax to cause movement. Muscles are generally of two types (1) voluntary muscle and (2) involuntary muscle.
The sarcomere is one of the base units of a skeletal muscle. These sarcomeres make up myofibrils. They consist of long chains of fibrous proteins such as actin, myosin and titin. These myofibrils are, in turn, constituents of long tubular cells called myocytes, or 'muscle cells'.If you find it difficult to remember the order; try remembering it in the same way you might remember how body systems are made up:Organism > Organ system > Organ > Tissue > CellMuscle > Myocyte > Myofibril > SarcomereThis represents the decrease in size from muscle to sarcomere.
the so called longitudinal bundles in the cytoplasm of a skeletal muscle are actually the muscle contractile proteins, namely actin and myosin.
A specific type of vacuole, called a contractile vacuole expels excess water from many fresh water protists.
the contractile ring
Simple proteins are composed of only amino acids. These proteins are also called monomeric proteins because they consist of a single polypeptide chain. The sequence of amino acids determines the structure and function of the protein.