Aerobic respiration in humans
requires a supply of glucose. Where does this glucose come
from? (A) From inhalation of gases from
the atmosphere. (B) From the breakdown of dead
cells. (C) From water in the person’s
diet. (D) From food in the person’s
Cellular respiration is the process
of converting energy in glucose to ATP to provide energy for our cells. There are two types of cellular
respiration, aerobic and anaerobic. Aerobic respiration requires the
use of oxygen, while anaerobic does not. In aerobic respiration, glucose is
combined with oxygen to make carbon dioxide, water, and energy in the form of
ATP. Glucose is a six-carbon molecule
with a ring structure as shown here. This question is asking us where we
receive glucose. So let’s go over the answer choices
to determine the best option.
In answer choice (A), we do not
receive glucose from inhaling gases. This is how we receive oxygen,
which is also required for aerobic respiration. So this answer is incorrect.
In answer choice (B), we do not get
glucose from the breakdown of dead cells. It may be possible to do this. But this isn’t how our body
primarily receives glucose.
In answer choice (C), glucose isn’t
made from water. Water contains hydrogen and oxygen
but no carbon atoms that are found in glucose.
In the final option, we do get
glucose from our diet. Foods like carbohydrates can supply
our body with high levels of glucose for aerobic respiration. Therefore, where glucose comes from
is given by answer choice (D), from food in the person’s diet.