myosin and actin

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Here is a model I made in Biology today, it's proper wicked.

This video shows that muscle contraction is dependent on ATP (the energy carrier in cells). The preparation of muscle is made from rabbit muscle. Most of the cellular content is removed and all that is left is the contractile machinery -- actin and myosin. The glycerinated muscle preparation is available from Carolina Biological Supply Company (item #203525 ATP Muscle Set; or # 203520 Glycerinated Skeletal Muscle; www.carolina.com).

Actin and Myosin interactions in muscle contraction

Dirtbikes

This is the Actin/Myosin action of the heart muscle.

Myosin VI fused with an artificial lever arm.

From UIUC MCB 150

From UIUC MCB 150

From UIUC MCB 150

Myosin VI fused with an artificial lever arm.

Simplified model of cardiac sarcomere. Myosin, actin, troponins, tropomyosin, myosin binding protein C, myopadin, Zasp, titin, actinin and other proteins in the cardiac myofilaments are shown

i had to do a project in my bio class about muscle contraction so i decided to do somthing a little different from the norm. i described the whole process of how a muscle contracts in a rap by Kanye West's "Stronger". lyrics: n- n- now th- that will move me muscle contractions make me stronger nervous system needs to hurry up now Cause muscles cant wait much longer I know they need to move right now Cause I cant get much wronger body is waitin till its the right time now that's where ill get started the muscle contraction the muscle contraction lets see how it starts all right? fuel by motor neuron were contraction starts stimulus leading is action potential and this makes a synapse with the muscle fiber the synaptic terminal release Ach diffuse through cleft and bind to fiber membrane it triggers, an action potential action potential moves down T tubules SR releases calcium ions Troponin is where calcium will then bind It changes the shape of troponin removes blocking action of tropomyosin the myosin-binding sites are now exposed this is how process goes down so far theres alot that makes up all this don't think we are through yet, so much more, explainin n- n- now th- that will move me muscle contractions make me stronger nervous system needs to hurry up now Cause muscles cant wait much longer I know they need to move right now Cause I cant get much wronger body is waitin till its the right time now that's where ill get started the muscle contraction the muscle contraction go again back to where we were then I will start so myosin is now exposed myosin cross-bridges alternate back and forth attachin and detachin to actin actin filaments move toward sarcomere sliding of filaments by ATP by active transport calcium removed Goes to SR with end of action potential Then block of myosin-binding site The contraction ends which is real tight Muscle fiber rests which is most liked With stimulus present again which is all right process starts over, contractions on sight that's how contractions go down, we tight? Ugh, muscle contraction makin it (harder, faster, stronger) n- n- now th- that will move me muscle contractions make me stronger nervous system needs to hurry up now Cause muscles cant wait much longer I know they need to move right now Cause I cant get much wronger body is waitin till its the right time now that's where ill get started the muscle contraction the muscle contraction now you know how it goes, don't ya? Muscle contraction is just another process Now explained no questions needed Don't act like I never told ya (5x) Muscle contraction makin it (harder, better, faster, stronger) n- n- now th- that will move me muscle contractions make me stronger nervous system needs to hurry up now Cause muscles cant wait much longer I know they need to move right now Cause I cant get much wronger body is waitin till its the right time now that's where ill get started the muscle contraction (4x) now you know how it goes, don't ya? Muscle contraction is just another process Now explained no questions needed Don't act like I never told ya now you know how it goes, don't ya? Muscle contraction is just another process Now explained no questions needed Don't act like I never told ya Never told ya (4x) Never over (8x) well i hope you guys enjoy and learn a little somthin about muscle contraction.

http://www.youtube.com/watch?v=MJ8sQTNNjkU Cytoskeletal Motor Proteins Ron Vale, July 2007 HHMI /Dept of Cellular and Molecular Pharmacology, University of California, San Francisco http://www.ascb.org/ibioseminars/Vale/Vale1.cfm Molecular motor proteins are fascinating enzymes that power much of the movement performed by living organisms. In the first part of this lecture, I will provide an overview of the motors that move along cytoskeletal tracks (kinesin and dynein which move along microtubules and myosin which moves along actin). The main focus of this lecture is on how motor proteins work. How does a nanoscale protein convert energy from ATP hydrolysis into unidirectional motion and force production? What tools do we have at our disposal to study them? The first part of the lecture will focus on these questions for kinesin (a microtubule-based motor) and myosin (an actin-based motor), since they have been the subject of extensive studies and good models for their mechanisms have emerged. I conclude by discussing the importance of understanding motor proteins for human disease, in particular illustrating a recent biotechnology effort from Cytokinetics, Inc. to develop drugs that activate cardiac myosins to improve cardiac contractility in patients suffering from heart failure. The first part of the lecture is directed to a general audience or a beginning graduate class.

A three hours hold fruit fly embryo is imaged laterally via fluorescence microscopy for 30 minutes. Myosin is tagged with GFP. This process, called gastrulation, serves in most higher organisms (including humans) for the formation of the three body layers: epi-, meso- and endoderm.

A cropped video showing Dicty cells larger. Wild type cells on the left migrate under agarose more slowly then myosin-2 mutant cells on the right. This time lapse video compresses 30 minutes to 15 seconds. Folic acid is a chemoattractant for these slime mold cells.

Three hour old fruit fly embryo imaged frontally by two-photon microscopy (transverse section). Myosin is tagged with GFP for fluorescence visualization.

An experiment showing how wild type cells on the left migrate under agarose more slowly then myosin-2 mutant cells on the right. This time lapse video compresses 30 minutes to 8 seconds. Folic acid is a chemoattractant for these slime mold cells.

A three hours hold fruit fly embryo is imaged ventrally via fluorescence microscopy for 30 minutes. Myosin is tagged with GFP. This process, called gastrulation, serves in most higher organisms (including humans) for the formation of the three body layers: epi-, meso- and endoderm.

Myosin - Actin Motility Assay

One police officer,FIRED...much money falsely accrued...charges pending...LOL Bigfoot has been found. ALIVE,NO DEAD,NO ALIVE,NO BOTH,SOME WERE ALIVE,SOME WERE DEAD,BUT WE CAN NOT SEE ANY OF THEM.WE CAN'T BE TOLD THE TRUTH...SO HERE IT IS AS BEST AS I CAN FIGURE Rigor mortis begins to manifest after about 3 hours after death, and lasts about 72 hours. It then disappears as proteolytic enzymes from lysosomes break down the crossbridges; that is the myosin heads detach from the actin filaments. This is known as resolution of rigor.

Riesenhafte Zellen Auf diese Weise erreicht die Riesenzelle oft gewaltige Ausmaße. Bei den meisten Arten werden die Plasmodien so groß wie eine menschliche Hand.Es gibt aber auch Arten wie Brefeldia maxima oder Physarum polycephalum, die über einen bis zwei Quadratmeter ausgedehnt sind. Ein besonders außergewöhnlicher Fund aus Großbritannien berichtet sogar von einem etwa viereinhalb Quadratmeter großen Exemplar der Art Trichia scabra, das sich in einem Ulmenstamm breit gemacht hatte. Das ist Rekord für die Größe einer Einzelzelle. Die schleimigen Vielfraße können sich mit einer Geschwindigkeit von einem Zentimeter in der Stunde fortbewegen und dabei sogar Hindernisse überwinden. Dabei helfen ihnen Myosin- und Aktinfäden in der Zelle Eiweißelemente, die zum Beispiel auch bei allen Säugetieren und den Menschen am Muskelaufbau beteiligt sind. Auf ungünstige Bedingungen wie Trockenheit oder fehlende Nahrung reagieren Plasmodien unterschiedlich: Manche Arten verhärten zu hornartigen "Sklerotien", die über Jahre hinweg überleben können. Andere reduzieren sich zu mikroskopisch kleinen Partikeln und werden erst dann wieder reaktiviert, wenn alles für das Überleben Wichtige stimmt.

Beryllium's high-tech take on the sliding filament theory.

sliding filament theory, actin myosin