Tutor profile: Grennady W.
Subject: Biomedical Science
Why are red blood cells biconcave in shape?
The most important role of red blood cells is to carry oxygen to cells. The biconcave shape allows red blood cells to flow smoothly through blood vessels and the narrowest of capillary and also maximizes the surface area for efficient oxygen delivery.
Why do some people turns red very quickly after a glass (or two) of beer and/or other alcoholic beverages?
This is called alcohol flush reaction and it is mainly caused by genetics. People with alcohol flus reaction typically have a mutation in the aldh2 gene, which in turn produces a less functional acetaldehyde dehydrogenase, an enzyme needed to break acetaldehyde which is a toxic byproduct of alcohol digestion. The less functional copy of this enzyme causes more acetaldehyde accumulation, which is associated with the redness that some people experience even after only consuming a relatively small amount of alcoholic beverages.
Mosquito is well known to transmit deadly blood borne pathogens such as Plasmodium parasites, which cause malaria. Another example of deadly blood borne pathogens is HIV virus, which causes AIDS. Can mosquitoes transmit HIV to human?
No, even if a mosquito bites a person infected with HIV and bites someone else, they cannot transmit the virus to the second person. HIV virus is unable to infect mosquito due to the lack of receptors in the surface of the mosquito's immune cells, which is required for the virus to enter and initiate their cell hijacking mechanism. Therefore, when the virus is ingested during blood feeding, it will just gets broken down and digested in the mosquito's stomach. Because they cannot get HIV infection, mosquitoes are unable to transmit HIV to humans.
needs and Grennady will reply soon.