Write a 100-350 word essay about the enzyme human CMAHP . Provide information related to enzyme: i) function, ii) reaction pathways, ii) Location, and iv) diseases. In writing include these four subheadings

### Function
Human CMAHP, or CMP-N-acetylneuraminic acid hydroxylase pseudogene, is the non-functional human counterpart of the CMAH gene found in other mammals. In other species, the CMAH enzyme converts N-acetylneuraminic acid (Neu5Ac) to N-glycolylneuraminic acid (Neu5Gc), a process critical in the modification of sialic acids on cell surfaces. However, due to a mutation in the CMAHP gene that occurred during human evolution, the enzyme is inactive in humans. As a result, humans do not naturally produce Neu5Gc, unlike other mammals.

### Reaction Pathways
In other mammals, the active CMAH enzyme catalyzes the hydroxylation of CMP-Neu5Ac to CMP-Neu5Gc, which is then integrated into glycoproteins and glycolipids on cell surfaces. In humans, due to the inactivation of CMAHP, this conversion does not occur. This leads to Neu5Ac being the predominant sialic acid in human cells. The absence of Neu5Gc production alters the way human cells interact with pathogens and the immune system, influencing susceptibility to certain diseases and immune responses.

### Location
If functional, the CMAHP enzyme would be localized in the cytoplasm, where it would participate in the modification of sialic acids. However, in humans, the CMAHP gene is a pseudogene, meaning it does not produce an active enzyme. As a result, the pathway leading to the production of Neu5Gc is absent in humans.

### Diseases
The inactivation of CMAHP has implications for human health and disease. Humans can incorporate Neu5Gc from dietary sources, particularly red meat, which can trigger an immune response since Neu5Gc is foreign to the human body. This immune response has been associated with chronic inflammation, and studies suggest a potential link to increased risks of cancer, atherosclerosis, and other inflammatory diseases. The evolutionary loss of CMAHP in humans is thought to have provided some advantages, such as altered susceptibility to certain pathogens, but also poses unique challenges related to modern diet and disease.