<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:
Explanation:
The production of ATPs for skeletal muscle contraction depends on the conditions that the muscles are exposed to.
In presence of abundant oxygen, to the cells Aerobic respiration-cellular respiration is the most ideal. 32 ATPs and 4 C02 are produced as by-products during the process as by products majorly two C02 from each of the 2 acetyl Co A that enters the kerb's cycle.
Likewise direct phosphoryaltion of ADP to ATP gives 32.0 kj/mol of heat liberated but no C02 was produced. This takes place during chemiosmosis. with 28ATPs produced.
In absence of oxygen, anaerobic respiration of skeletal muscles produced ATPs from glycolysis, heat and 2C<u>02 as products, but not as by-product</u>.Through alcoholic fermentation pathway.
Therefore ,the correct answer is Aerobic respiration, because it gives out C02 which is a by-product, released out of the body as waste from the lungs,and not use up in the body.
Explanation:
D. E: photosynthesis; D: cellular respiration
Photosynthesis is a chemical pathway that’s integral to producing energy in plants and other primary producers. Energy in the form of molecules of glucose is produced from light, water and carbon dioxide while oxygen is released. This occurs in several complex steps, photosynthesis is a rate limited reaction, depends on several factors including carbon dioxide concentration, ambient temperature and light intensity; the energy is retrieved from photons, I.e. particles of light, and water is used as a reducing agent.
In the light reactions, occuring within the thykaloid, and stroma of the chloroplasts, water supplies the pigment chlorophyll with replacement electrons for the ones removed from photosystem II. Additionally, water (H2O) split by light during photolysis into H+ and OH- acts as a source of oxygen along with functioning as a reducing agent; it reduces the molecule NADP to NADPH by providing H+ ions. NADP and NADPH are integral to the dark reactions, or Calvin cycle where monosaccharides or sugars like glucose are produced after the modification of several molecules.
Respiration in the mitochondria utilizes oxygen for the production of ATP in the Krebs’s cycle via the oxidization of pyruvate (through the process of glycoysis). The electron transport chain, in which oxygen functions as the terminal electron acceptor, occurs in both plants and animals. Respiration includes:
- Glycolysis: occurs in the cytoplasm 2 molecules of ATP are used to cleave glucose into 2 pyruvates, 4 ATP and 2 electron carrying NADH molecules.
- The Kreb's cycle: in the mitochondrial matrix- 6 molecules of CO2 are produced by combining oxygen and the carbon within pyruvate, 2 ATP oxygen molecules, 8 NADH and 2 FADH2.
- The electron transport chain, ETC: in the inner mitochondrial membrane, 34 ATP, electrons combine with H+ split from 10 NADH, 4 FADH2, renewing the number of electron acceptors and 3 oxygen; this forms 6 H2O, 10 NAD+, 4 FAD.
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