Ads
related to: cross-bridge cycle mcat- 7 Days Free Trial
We are academic experts. Learn
from top subject matter expert
- UWorld MCAT Prep Course
One stop resource for MCAT
Expertly-Written Books & QBank
- Know you are prepared
provide a deep understanding
of concepts. #1 Question Bank
- Top-tier explanations
Interface just like MCAT
Integrated Spaced Repetition
- 7 Days Free Trial
Search results
Results from the WOW.Com Content Network
Cross-bridge theory states that actin and myosin form a protein complex (classically called actomyosin) by attachment of myosin head on the actin filament, thereby forming a sort of cross-bridge between the two filaments. The sliding filament theory is a widely accepted explanation of the mechanism that underlies muscle contraction.
Cross-bridge cycle. Cross-bridge cycling is a sequence of molecular events that underlies the sliding filament theory. A cross-bridge is a myosin projection, consisting of two myosin heads, that extends from the thick filaments. [1] Each myosin head has two binding sites: one for adenosine triphosphate (ATP) and another for actin.
Specifically, it increases the rate of phosphate release from myosin by stabilizing the pre-powerstroke and the phosphate release states, [8] thereby accelerating the rate-determining step of the cross-bridge cycle, which is the transition of the actin-myosin complex from the weakly bound to the strongly bound state.
Activation consists of phosphorylation of a serine on position 19 (Ser19) on the MLC 20 light chain, which causes a conformational change that increases the angle in the neck domain of the myosin heavy chain, [8] which corresponds to the part of the cross-bridge cycle where the myosin head is unattached to the actin filament and relocates to ...
The phosphorylation of MLC will enable the myosin crossbridge to bind to the actin filament and allow contraction to begin (through the crossbridge cycle). Since smooth muscle does not contain a troponin complex, as striated muscle does, this mechanism is the main pathway for regulating smooth muscle contraction. Reducing intracellular calcium ...
The binding of the myosin head to actin is known as a cross-bridge. A molecule, called adenosine triphosphate (ATP) which is produced by an intracellular structure called a mitochondrion, is then used, as a source of energy, to help move the myosin head, carrying the actin. As a result, the actin slides across the myosin filament shortening the ...
Language links are at the top of the page. Search. Search
The fall in concentration of Ca 2+ ensures that the myosin light-chain kinase (MLCK) can no longer phosphorylate the myosin molecule, thereby stopping the crossbridge cycle and leading to relaxation of the smooth muscle cell. [37] NO is also generated by phagocytes (monocytes, macrophages, and neutrophils) as part of the human immune response. [38]
Ads
related to: cross-bridge cycle mcat