Actin

Calcium binds to troponin, whose affinity to actin is now higher than tropomyosin, the molecule covering the binding site of actin (Silverthorn, 2007). Adenosine-Diphoshate-bound myosin heads now bind to the active site to form cross-bridges and achieves a power stroke (Silverthorn, 2007). The power stroke causes the contraction of contractile fibres (Silverthorn, 2007). Relaxation begins when ATP binds to myosin which causes its release from the actin binding site (Silverthorn, 2007). Ca2+…

Rigor Mortis The term rigor stems from the Latin term meaning stiffness. Mortis stems from the Latin term meaning death. Upon death, respiration ceases to occur. Without oxygen, metabolism stops, organs shut down. The body’s main source of energy is the cell production of ATP. Wikipedia’s definition:” Adenosine triphosphate (ATP) is a nucleoside triphosphate used in cells as a coenzyme often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical…

muscle fibre is made up of thousands of myofibril containing billions of myofilaments (Frontera and Ochala 2015). The building block of these myofibrils is the sarcomeres which are the basic contractile units of skeletal muscle. They are made up of actin and myosin filaments that are divided by a thin sheet of structural proteins called the Z band/ Disk. (Book…

Unfavorable has a negative connotation, it conjures up thoughts of ‘bad” and “non-useful” processes, however as we have learned through the case studies of muscle contraction and photosynthesis, this is simply a misconception. For in the natural world a favorable or unfavorable reaction is not a single entity but is rather part of a coupled reaction that uses the two in tandem to continue the function of essential processes. This being said, and connotation aside, an unfavorable reaction is one…

There are billions of neurons in our brain that sends signals from the axon to the spinal cord. In the spinal cord the axon on will send signals to many neurons from other cells and then it will generate an order. The membrane potential is an electrical state of the cell membrane and it allows gradients that cause ions to move across the cell membrane. The dispersal of charge across the cell membrane is measured in (mV). The resting membrane potential is the difference between the charges…

lastly well three contained 1,740 cells in total. We weren’t surprised by our results because we had a lot of waiting time in order for the cells to grow. 2. All of the dyes were visible under the fluorescent microscope. The green dye stained the actin, the red dye stained for mitochondria and the blue dye stained for dsDNA. If someone would not be able to see these pictures it would indicate contamination and they would not contain organelles and proteins. It can also indicate denaturation…

the myosin heads for binding to actin forming a cross-bridge and then the myosin head bends, which release ADP and phosphate. At the molecular level, Fox explains that the muscle filaments are composed of actin monomers in a…

β1 integrins (32, 64). Once these connections are established, the extracellular domain of ICAM5 is cleaved, disrupting the cytoplasmic actin cytoskeleton through to α-actinin or ERM (ezrin/radixin/moesin) proteins promoting reorganization to induce spine maturation (31-34, 34, 65, 66). Based on the role of ICAM5 in cell adhesion and its ability to alter the actin cytoskeleton, we propose that ICAM5 may play a role in structural organization of functional homotypic cell networks within the…

myofibrils, which not only give the muscle its striated appearance but also are also composed of contractile proteins known as actin (thin filaments) and myosin (thick filaments). Each actin protein has a binding site for myosin, which is regulated by two proteins known as Tropomyosin and Troponin. Both of these regulator proteins inhibit the binding of myosin to actin by overlapping the binding sites in a confirmation that could be described as a ribbon (Tropomyosin) and a thumbtack (Troponin)…

The knee-jerk reflex is considered a stretch reflex and is often used by physicians to test how the nervous system is functioning. The knee-jerk reflex is tested by tapping the patellar tendon with the base of a rubber hammer. This results in the leg and foot extending upward in healthy individuals. The reflex is a response to the change in shape of the patellar tendon and quadriceps muscle. It does so to prevent damage to the muscle and ultimately the maintain homeostasis. There are a series…