The Air That I Breathe Trivia Quiz

Answer: About 20%

The air at sea level (where most of the people on earth live) contains around 78% nitrogen plus 21% oxygen, nearly 1% argon and 0.04% carbon dioxide. For humans, nitrogen and argon are inert. This means that we can't use this gas to keep us alive, but it does not harm us either.

As only about 20% of air is oxygen, when we take a breath of about 500mL of air only 100 mL is used by the body.

Answer: The nose has little hairs which stop foreign matter entering the lungs

When we breathe, the air nearly always enters our nose where hairs called cilia trap dust, pollen, mould and other environmental contaminants. The nose also moisturises and warms the air before it reaches the lungs. If the mouth is used for breathing none of these things happen but the distance to the throat is shorter and wider so air can reach the lungs quicker if needed.

Answer: Oxygen from the air moves into the bloodstream

The place where the alveoli meets the bloodstream is a very complex part of our anatomy. However, oxygen is able to be filtered from the air and attached to a molecule called hemoglobin which is a protein that is part of every red blood cell. Each red blood cell carries the oxygen to where it needs to go.

Answer: Left Ventricle

The oxygenated blood moves to the heart and enters it through the left atrium. The blood then moves downward into the left ventricle where the brain tells it to contract pumping about 70 mL of blood all around the body. The left ventricle is the largest of the four chambers of the heart.

Answer: Capillaries

The blood travels though large vessels when it leaves the heart, and, as the blood travels further away from the body it moves through narrower and narrower vessels until in some of the smaller capillaries, the capillary is so small, the red blood cells move through them in single file. It is in these capillaries where the oxygen detaches from the red blood cell.

Answer: In nearly every cell in the body

The place where the chemicals derived from food are converted into energy occurs at the cellular level. Energy-containing molecules are mainly fats and carbohydrates that have been broken down into smaller molecules elsewhere in the body. These molecules all contain at least one carbon atom.

These molecules are converted into energy. Oxygen is essential for this chemical reaction. At the end there are always some carbon molecules left over which need to be taken outside of the cell.

Answer: One atom of carbon + two atoms of oxygen

Carbon dioxide is one atom of carbon and two atoms of oxygen. This is the form the carbon leaves the cell as it is a gas; carbon on its own is a solid.
One atom of carbon and one atom of oxygen is carbon monoxide which is poisonous as if inhaled it stops the red blood cells from carrying oxygen.
Two atoms of oxygen is an oxygen molecule.
Two atoms of hydrogen is how hydrogen is found in the atmosphere (in very low concentrations). In the body hydrogen combines with leftover oxygen to form H2O which is water.

Answer: Right Atrium

The deoxygenated blood enters the right atrium at the top of the heart then moves downward into the right ventricle. When it is full a valve between the atrium and the ventricle shuts to stop blood escaping back into the ventricle. The heart then contracts.

Answer: The carbon dioxide is released into the alveoli of the lungs

The carbon dioxide (CO2) is then released from the red blood cells and moves into the alveoli and eventually moves through the lungs, through the throat and out of the mouth (or nose). At the same time the CO2 is released, oxygen combines with the red blood cells and the whole cycle repeats itself by returning to the left side of the heart where a contraction sends it around the body.

Answer: Trees and plants convert the carbon dioxide into oxygen

The process by which our bodies convert oxygen into CO2 to provide energy is called respiration. Trees and plants perform the reverse process: they convert CO2 into oxygen to produce energy. Oxygen is released by trees/plants into the atmosphere making it available for humans and animals. This process is called photosynthesis.