Myosin

Introduction Actin and myosin are two major proteins that are involved in muscle contraction. Actin is the main constituent of thin filaments in muscle cells, whereas myosin, comprised of a head and tail region, is the main component of thick filaments. These proteins coordinate muscle contraction by means of a sliding mechanism whereby myosin heads affix to the thin filaments, composed of actin, and revolve, resulting in an overlap of the filaments whereby stretching or contraction of a muscle occurs. While it was believed that actin and myosin were only involved in muscle contraction, recent scientific investigation has determined that these “muscle proteins”, also work in several other processes including the formation of contractile rings…

four question analysis on "The myosin-interacting protein SMYD1 is essential for sarcomere organization" by Just et al. (2011) 1.) Wild-type Fla Mutant (SMYD-deficient) In the current study, the authors used a zebra fish mutant known as Flatline (fla). This mutant contains a nonsense mutation within the SMYD1 gene, consequently, these mutants show disturbed sarcomere assembly. The authors observed that fla mutants had properly…

In class, we’ve talked about the myosin when seeing the microfilament. It is the motor protein of microfilament which moves along it tracks toward the positive end. It is also the major component of skeletal muscle thick filaments and thus, is involved in muscle contraction. The disease that is going to discuss is related to muscle contraction, called Myosin Storage Myopathy (also known as hyaline body myopathy). The characteristic or symptom of this disease is the weakness of the muscles that…

Muscles in a way are the most important parts of the body. If we didn’t have muscles it would be impossible to move around, and do things. Muscles make everything we do possible, but there is more to muscles than meets the eye. Yes there are the kinds of muscles which allow us to walk and pick up things, but there are also different kinds of muscles which if anything are equally important. Before we dive into the kinds of muscles and their functions, let’s get a better idea of how muscles work.…

Overview of The Myocyte The myocyte is composed of various protein filaments that comprise the contractile apparatus of the cardiac cell. Myofibrils, a collection of individual sarcomeres, enable contraction and relaxation of the myocyte. The sarcomere is the chief contractile unit of the cell. It is made up of two main proteins, myosin (thick filament) and actin (thin filament), as well as two regulatory proteins, tropomyosin and troponin. In order for the myocyte to contract and shorten it…

There are many different parts of skeletal muscles that are important to the function of the muscles. Each muscle is made up of a lot of muscle fibers. Each muscle fiber has a thin coating covering the fiber called the sarcolemma. The muscle fibers also have a cytoplasmic type substance called sarcoplasm. Sarcoplasm contains large amount of glycosomes and myoglobin. Myoglobin is a protein that stores oxygen inside the muscle fibers. The muscle fibers contain striations that are made up of…

along the fiber. The contractile element of a muscle lies within the myofibril, a smaller component of the muscle fiber. Each myofibril contains thick and thin filaments made of actin, myosin, tropomyosin and troponin. The myosin molecule makes up the thick filaments and the head contains the actin and ATP binding site. The thin filament…

called a concentric contraction. When muscles increase in length (e.x. doing pushups) it is called an eccentric reaction. There are two proteins responsible for muscle contractions: Actin and Myosin. The interaction of Actin filaments gliding over Myosin filaments is what causes the shape change in muscle cells. The physical process of muscles contracting happens rapidly.…

Once the bridges are formed, the myosin pulls on the actin contracting the muscle. Cross bridge formation can only occur, however, when the binding sites on the actin are free. Calcium ions work to free up the myosin binding sites on actin. When a muscle is relaxed, a protein called tropomyosin blocks the myosin binding site. Calcium rushes into the cell and attaches to a special protein troponin when a muscle is stimulated by a nerve cell. The troponin then changes shapes and pulls the…

1. Skeletal muscle used ATP to contract. Then, ATP is broken down into ADP and P, which release energy. 2. A) The sarcoplasmic reticulum is the organelle that stores calcium in muscles cells. B) In order for calcium to be released from this organelle some events must occur. First, an action potential needs to reach the synaptic terminal. Then acetylcholine needs to be released into the sarcoplasm. After that, ACH molecules will land on receptors that are on the motor end plate. Then, an action…