<span>There are numerous proteins in muscle. The main two are thin actin filaments and thick myosin filaments. Thin filaments form a scaffold that thick filaments crawl up. There are many regulatory proteins such as troponin I, troponin C, and tropomyosin. There are also proteins that stabilize the cells and anchor the filaments to other cellular structures. A prime example of this is dystrophin. This protein is thought to stabilize the cell membrane during contraction and prevent it from breaking. Those who lack completely lack dystrophin have a disorder known as Duchene muscular dystrophy. This disease is characterized by muscle wasting begininng in at a young age and usually results in death by the mid 20s. The sarcomere is the repeating unit of skeletal muscle.
Muscle cells contract by interactions of myosin heads on thick filament with actin monomers on thin filament. The myosin heads bind tightly to actin monomers until ATP binds to the myosin. This causes the release of the myosin head, which subsequently swings foward and associates with an actin monomer further up the thin filament. Hydrolysis and of ATP and the release of ADP and a phosphate allows the mysosin head to pull the thick filament up the thin filament. There are roughly 500 myosin heads on each thick filament and when they repeatedly move up the thin filament, the muscle contracts. There are many regulatory proteins of this contraction. For example, troponin I, troponin C, and tropomyosin form a regulatory switch that blocks myosin heads from binding to actin monomers until a nerve impulse stimulates an influx of calcium. This causes the switch to allow the myosin to bind to the actin and allows the muscle to contract. </span><span>
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Animalia is the label that appears to differentiate animals from organisms on other kingdom.
Explanation:
Scientists uses the process called taxonomy to classify the organisms based on their structure, functions and relationship to other organisms.
Eukaryotes represents the domain of life. Domain Eukarya are classified into four kingdoms they are protista, fungi, plantae and animalia.
The kingdom protista represents the organisms that are simple structured and they swim through the water and obtain nutrients from the environment.
In the kingdom fungi like mushrooms absorb nutrients from the environment and they are heterotrophs.
In the plantae kingdom the organisms are plants and they are autotrophs. They prepare their own food.
In Animalia kingdom the organisms are animals and they are multicellular heterotrophs. They do not have cell walls and the reproduction is done sexually and some can reproduce asexual.
Identify the anatomical features of a bone
Define and list examples of bone markings
Describe the histology of bone tissue
Compare and contrast compact and spongy bone
Identify the structures that compose compact and spongy bone
Describe how bones are nourished and innervated
Fungi are effective decomposers, saprophytic fungi grow towards their food source, mycelia produce extracellular enzymes to digest food outside of hyphae, saprophytic fungi like miners: they blast away lignin to expose cellulose, fungi use other enzymes to degrade cellulose to glucose.
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