Answer:
The source of Calcium (Ca⁺⁺) for the skeletal muscle cells is the sarcoplasmic reticulum, the main store of intracellular Ca⁺⁺.
Explanation:
Calcium (Ca⁺⁺) is an ion that plays an important role in muscle contraction, a process that requires high cytoplasmic concentrations of this ion to promote myofibrillary activity.
The sarcoplasmic reticulum (SR) -equivalent to the endoplasmic smooth reticulum- is an organelle that regulates the contractile activity of skeletal muscle. The two terminal cisterns of the SR attach to the T-tube, forming a triad, which surrounds the myofibrilla.
Once the muscle cell receives the signal to contract, the Ca⁺⁺ channels are opened and allow Ca⁺⁺ to enter the cell, promoting the exit of this cation from the SR and increased its cytoplasmic levels. This stimulates muscle contraction.
Glycolysis uses 2 ATP and produce 4ATP. So the net gain is true.
Oxygen is used in the Electron Transport Chain as the final electron recipient from complex 4 cytochrome a₃.
Explanation:
Glycolysis is the process which is common in all forms of respiration where glucose is metabolized into pyruvate. This process is very essential to continue the next steps of different respiration. Glycolysis requires 2 molecules to process substrate level phosphorylation to convert glucose to glucose 6 phosphate and fructose 6 phosphate to fructose 1, 6 bisphosphate. But it produces 4 ATPs. Thus net gain is 2ATP.
In ETC, the hydrogen carriers NADH and FADH gives off the hydrogen to reduce the complex 1 and 2 respectively and itself gets oxidized. Thus the electron given off is transferred between 4 complexes to finally give off to oxygen to form water.
Explanation:
Meiosis produces haploid gametes (ova or sperm) that contain one set of 23 chromosomes. When two gametes (an egg and a sperm) fuse, the resulting zygote is once again diploid, with the mother and father each contributing 23 chromosomes.
Answer: Option B) They can be altered reversibly during a reaction.
Explanation:
An enzyme is a proteinous substance that catalyzes a specific chemical reaction. It does not affect the equilibrium of the catalyzed reaction, and it always remain unaltered during the reaction process.
Thus, becoming altered is not a characteristic of enzymes
