Myosin

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…

phosphorylation of various proteins. Increased cytosolic Ca2+ level promotes binding of Ca2+ to calmodulin, increasing the Ca2+/calmodulin concentration which is essential in activating myosin light chain kinase (MLCK). MLCK then phosphorylates myosin light chain (MLC), leading to the formation of cross-bridge between actin and myosin, thus…

skeletal muscle, on the other hand, is a specialized tissue actively involved in the production of the tension force required in moving the skeletal system. The tension force in the tissue is produced due to the interactions between the actin and myosin.…

the end plate threshold and then rush into the axon terminal. The calcium released from the terminal cisternae of the sarcoplasm reacts on troponin, which exposes the myosin-binding site. The myosin heads latch on to the actin exposing active binding site, which form cross bridges. This is a series of events during which the myosin heads pull thin filaments toward the center of the sarcomere, resulting in the sliding of myofilaments (Marieb/Hoehn, 2014). This continues as long as ATP is…

State the optimum pH for sucrase activity and describe how sucrase activity changes at more acidic and more alkaline pH values. Table 2: Effect of Temperature on Sucrase Activity Optical Density 10 °CC (50 °F) 20 °C (68 °F) 30 °C (86 °F) 40 °C (104 °F) 50 °C (122 °F) 60 °C (140 °F) 70 °C (158 °F) 1 0.006 0.273 0.791 0.940 0.927 0.807 0.613 2 0.010 0.285 0.761 0.954 0.934 0.846 0.604 3 0.009 0.255 0.773 0.941 0.907 0.845 0.642 average 0.008 0.271 0.775 0.945 0.923 0.833…

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+ returns back to the SR via Ca2+ ATPase and…

group of proteins called myosin. Thin filaments are formed from three proteins called actin, troponin and tropomyosin. Muscle tissue is described in terms of units called sacromeres. These units are defined as overlapping groups of the thick and thin filaments. The length of a sacromere and the zones within each sacromere (H zone, I band and A band) are determined by the position of how the thick and thin filaments are relative to each other. During muscle contraction the myosin heads on the…

Determining phylogenetic relationships of marine invertebrate and vertebrate using variation in muscle proteins of different genera; Ostreidae , Teuthida, Pectinidae, Nephropidae, Caridea, Brachyura and Oncorhynchus. Introduction The fundamental core of all biology emanates from evolution, as the great evolutionary biologist Theodosius Dobzhansky once said "Nothing in biology makes sense except in the light of evolution"(1973). Therefore, studying the phylogenetic relationships of different…

1. The peripheral nervous system, which is divided into the sensory and motor divisions, is involved in physical sensation. Sensory impulses move though the body by being stimulated by a receptor in the skin. It then travels to the sensory neurons and through the afferent fibers, were it will end up at the spinal cord as well as the brain. 2. The motor division of the nervous system are involved in skeletal muscle movement. Motor impulses move through efferent fibers. A motor unit is a motor…

1. What are the functional classifications for the biceps and triceps muscles in the bicep curl movement? What type of contractions are the biceps and triceps performing during a bicep curl? There are two functional classifications for the biceps and triceps muscles, which are the following: agonists and antagonists. The agonist generates the most powerful force in the biceps, in comparison to the triceps. The Triceps focuses on protecting the muscles from hyperextending the arm, by using the…