Question

In Bohr effect, curve shift to right
A. $PCO_2$ decreases and $PO_2$ increases
B. $PCO_2$ increases and $PO_2$ decreases
C. $PCO_2$ increases and $PO_2$ increases
D. $PCO_2$ increases and $PO_2$ increases and $pH$ increases

Answer 1

Oxygen binds to haemoglobin competitively and reversibly, with some modifications altering the affinity with which this interaction exists within the setting. The oxygen dissociation curve's sigmoidal shape reflects the propensity of haemoglobin for positive cooperativeness, as haemoglobin undergoes conformational changes to increase its oxygen affinity as molecules steadily bind to each of its four accessible binding sites.

Complete answer:
The Bohr effect describes the lower affinity of haemoglobin for oxygen secondary to increased carbon dioxide partial pressure and decreased $pH$ in the blood. This lower affinity, in turn , increases the unloading of oxygen into tissues to meet the tissue's oxygen demand. Increases in metabolic activity within tissues result in the production of carbon dioxide as a metabolic waste product through the biochemical reactions needed for cellular respiration.This increase in tissue contributes to an increase in the concentration of hydrogen ion, represented as a decrease in $pH$ as the acidosis process is undergone by the environment. These effects reduce the affinity of haemoglobin for oxygen, weakening its binding potential emitted will be increased when the tissue is more active. More $H^{+}$ is produced as the amount of carbon dioxide increases, and the $pH$ will decrease.
A lower $pH$ in the blood indicates an increased concentration of carbon dioxide, which means that the more active the tissue is, the greater the amount of oxygen needed.
The lower $pH$ would allow Hb to deliver more oxygen, according to Bohr.

Hence, the correct answer is option (B).

Note: The effect of Bohr refers to loss of oxygen affinity with decreasing $pH$ (increasing acidity) in microcirculation as oxygen is consumed and carbon dioxide is released by tissues. Carbon dioxide reacts with water to form carbonic acid, increasing carbon dioxide concentration contributes to a decrease in blood $pH$ , resulting in haemoglobin proteins releasing their oxygen load.
and increase the risk of dissociation; this is represented as a change to the right of the dissociation curve of haemoglobin, as haemoglobin discharges oxygen at higher partial oxygen pressures from its binding sites. The amount of oxygen would be lower if the tissue were to use more oxygen.