Muscle cells have enzyme which not only breaks down ATP to ADP (creatin), but can also make ATP from ADP by using phosphokinase. .
Myokinase also produce ATP. ADP + ADP ------------ ATP + AMP.
ATP is regenerated by process such as glycolysis and mitochondrial oxidative phosphorylation. In muscle cell, the enzyme creatin kinase and creatin phosphate aid in this process.
The difference between a contracted muscle and a relaxed muscle is; a contracted muscle has the maximum overlap between the actin and myosin filaments. However, there is no overlap at the H-zone of thick and thin filaments. The Z-lines/disk move closer together. During contraction the think and thin filaments remain constant, but the sarcomere is shorter in length. For a relaxed muscle, the opposite occurs, there is a little over with the thick and thin filaments. The sarcomere are longer in length, hence the Z-disk/lines are further apart. There is much more visible H-zone.
B) Cytoskeleton and Cell Motility II.
There are several blotting techniques. Northern blot is used for identifying RNA transcripts of specific genes. Southern blot is used for DNA fragments. However, we used western blot also known as protein blotting technique. The first step involves the separation of protein by gel electrophoresis, then the transfer of the separated protein to nitrocellulose paper, finally the analysis of absorbed protein by incubation of the blotted nitrocellulose with antibodies of interest. .
There were proteins transferred on the stained filter where they were trapped hence, bands of stain marks appeared. The nitrocellulose paper was incubated in blocking medium containing protein to prevent non-specific binding by the primary antibody. The primary antibody we used was monoclonal, which was made in mouse against rabbit sarcomeric actin. The primary antibody (anti-actin) did visualize the band. The secondary antibody we used was anti-mouse IGM made in goat to which the enzyme alkaline phosphatase is labeled.
