Question

Which one of the following mammalian cells are not capable of metabolizing glucose to carbon-dioxide aerobically?
(a)Red blood cells
(b)White blood cells
(c)Unstriated muscle cells
(d)Liver cells

Answer 1

The mammalian cell that is unable to aerobically metabolize glucose into carbon dioxide is the one that takes up oxygen in the lungs or the gills in fish and releases it into tissues while squeezing through the capillaries of the body.

Complete answer:
The aerobic respiration process in animal cells is carried out in the mitochondria. At maturity, mammalian red blood cells (RBC) lose all cell organelles and haemoglobin occupies the vacuum, so they also lack nuclei, mitochondria, and all other major cell organelles.
They generate energy by fermentation, through glucose glycolysis, followed by the production of lactic acid. In addition, red cells do not have an insulin receptor and, thus, insulin does not control glucose uptake. As a result of the absence of nuclei and organelles, new structural or repair proteins or enzymes can not be produced by cells and their lifetime is reduced.
RBCs are therefore unable to aerobically metabolize glucose into carbon dioxide and rely on anaerobic respiration for their energy needs.
So, the correct answer is, ‘Red blood cells’.

Note: In the presence of oxygen, aerobic respiration takes place and eventually degrades glucose into carbon dioxide and water with the release of energy in the form of ATP.
Often known as haematodes, erythroid cells or erythrocytes are red blood cells (from Greek erythros for 'red' and kytos for 'hollow vessel' with a cyte in modern usage translated as 'cell'), are the most common type of blood cells and the primary means of providing oxygen to the vertebrate.