20%
The lowest concentration of oxygen in the body is in the venous blood returning to the heart. This blood has delivered oxygen to tissues and organs and is now returning to the heart to pick up more oxygen in the lungs through respiration.
the Right side
heart
The left side of the heart contains oxygen-rich blood. The right side of the heart contains deoxygenated blood.
The right side of the heart pumps oxygen-poor blood into the lungs for oxygenation.
The difference in concentration of oxygen on either side of the cell membrane creates a concentration gradient that drives the diffusion of oxygen from an area of higher concentration to an area of lower concentration. The greater the concentration gradient, the faster the rate of diffusion, as molecules naturally move to achieve equilibrium. This process is crucial for cellular respiration, as cells require a continuous supply of oxygen to generate energy. If the concentration difference is minimal, the rate of oxygen diffusion will be slower.
It receives oxygen
The right side of the heart pumps deoxygenated blood (blood deprived of oxygen) to the lungs where it can then receive oxygen.
The right side of the heart pumps blood to the lungs to pick up oxygen. From the lungs it goes back to the left side of the heart, which pumps it out to the rest of the body. Blood then returns to the right side of the heart and starts the cycle over.
On the left it's blue and on the right it's red, but the heart curves in a way where it's on both sides.
Blood in the left side of the heart is redder because it is carrying oxygen.
Because, on one side of heart is pure and other is impure. That's why in diagrams and illustration show one side of the heart red and other side is shown in blue colour.