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.…

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…

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…

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…

to Ra, lowering the length constant. 4. Adenosine triphosphate (ATP) plays an important role in a striated muscle twitch, especially in the cross-bridge cycling. In a relaxed state, ATP is partially hydrolyzed at the binding site in myosin, keeping myosin in a high-energy state. When there’s an elevated Ca++ inside a muscle cell, high-energy state myosin binds to actin, forming the cross-bridge. Upon cross-bridge formation, ATP is hydrolyzed, which causes a conformational change in the myosin…