Answer: Option D. "Heme"
Explanation:
Deoxyhemoglobin can be defined as a form of which has no oxygen binded to the hemoglobin.
When deoxyhemoglobin is replaced with oxyhemoglobin then the oxygen binds to the heme component of the hemoglobin protein in red blood cells.
Each heme group has iron atom that has the ability to bind to oxygen (02) molecule.
Four oxygen molecules bind to a single hemoglobin protein.
Hence, the correct answer is option D "Heme".
Answer:
Okay
Explanation:
Human topoisomerase I plays an important role in removing positive DNA supercoils that accumulate ahead of replication forks. It also is the target for camptothecin-based anticancer drugs that act by increasing levels of topoisomerase I-mediated DNA scission. Evidence suggests that cleavage events most likely to generate permanent genomic damage are those that occur ahead of DNA tracking systems. Therefore, it is important to characterize the ability of topoisomerase I to cleave positively supercoiled DNA. Results confirm that the human enzyme maintains higher levels of cleavage with positively as opposed to negatively supercoiled substrates in the absence or presence of anticancer drugs. Enhanced drug efficacy on positively supercoiled DNA is due primarily to an increase in baseline levels of cleavage. Sites of topoisomerase I-mediated DNA cleavage do not appear to be affected by supercoil geometry. However, rates of ligation are slower with positively supercoiled substrates. Finally, intercalators enhance topoisomerase I-mediated cleavage of negatively supercoiled substrates but not positively supercoiled or linear DNA. We suggest that these compounds act by altering the perceived topological state of the double helix, making underwound DNA appear to be overwound to the enzyme, and propose that these compounds be referred to as ‘topological poisons of topoisomerase I’
Answer:
It could be a fractured knee or out of place
Explanation:
His leg felt like giving out when attempting to walk. He explains that he twisted his knee while trying to change direction. He heard a loud pop as his knee gave in.
