<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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Answer:
Sediment in rivers gets deposited as the river slows down. Larger, heavier particles like pebbles and sand are deposited first, whilst the lighter silt and clay only settle if the water is almost still.
Answer:
mitosis, cell growth, and differentiation
Explanation:
There are several ways through which plants grow which may include the process of mitosis mainly that involves cell division. The increase in height in plants is attributed to not only cell division but also growth of the newly formed cell.
Mitosis involved division of cell and in cell growth, cells increase their size that ultimately cause growth of plant height. The highly active growth cells are meristem cells that are found at tips of the plants. They are actively dividing zones of plants and with their division and growth plant increases their heights.
Another mechanism, responsible for increase in height is cell differentiation. Differentiation is the process during which cells are specialized to perform specialized function. For example: Xylem are specialized for transport of water. Phloem are specialized for the transport of food. Similarly, some cells are specialized for growth and they are aimed at increasing in size and division that ultimately increase the plant height.
So, mitosis, cell growth, and differentiation are the mechanisms, that increase plant height due to changes in specialized regions of cells in the tips of their branches.
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Answer:
DNA is functional is the transmission of genetic information. It forms as a media for long-term storage. RNA is functional is the transmission of the genetic code that is necessary for the protein creation from the nucleus to the ribosome. The DNA is a double-stranded molecule that has a long chain of nucleotides.
The f° -f^1 complex in the mitochondrial structure helps it
