Myosin

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 assembled hearts with healthy myo- and endocardial cell layers but their cardiac tissue showed no contraction under stimulation. They also concluded that the cardiac electrical impulse was the same for both wild-type and…

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…

shortening the sarcomere. These two filaments do the real job of a muscle. Thick filaments are comprised by a protein called myosin, which has significant assets of resistance and contractibility. These myosin protein molecules are shaped like a pair of hockey sticks twisted together. On the other hand, thin filaments are made up by a protein called actin. Molecules of actin connected to one another form chains twisted into a helix structure. Actin plays a crucial role for the mechanism in…

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…

As mentioned previously, the amount of force produced by a muscle is linked directly to the number of actin and myosin fibers in a muscle. This explains why the larger muscles which contain a greater number of actin and myosin, produce a greater force. Resistance training can cause the muscle size to grow in two ways, hypertrophy or hyperplasia (Powers, 2015). Hyperplasia is an increase in the total number of muscle fibers in a single muscle. However, there is not much evidence that muscle…