Final answer:
Amino acids can act as buffers by accepting or donating protons, and thereby, they play a role in maintaining pH homeostasis in the body. They exist as zwitterions at physiological pH, which allows them to react to changes in pH by either getting positively or negatively charged. The transport of amino acids into cells may be affected by changes in the external pH.
Step-by-step explanation:
Amino acids can influence a person's body pH, which refers to whether the body is acidic, neutral, or alkaline. The buffering capabilities of amino acids mean they can both donate and accept protons (hydrogen ions) depending on the surrounding pH. When the body is in a state like ketosis or under protein catabolism, amino acids can be broken down, leading to the release of ammonia (NH3) which then accepts H+ to become ammonium (NH4+), acting as a buffer and influencing the pH.
Furthermore, amino acids exist as zwitterions at physiological pH, meaning they contain both positive and negative charges, thus allowing them to act as buffers. They can help maintain the pH by either accepting or donating H+ ions depending on whether an acid or base is added to the system. This buffering system is essential for maintaining the delicate pH balance in the body, necessary for optimal biochemical functioning.
In terms of amino acid transport into cells, if the external pH decreases, it implies an acidic environment, which could affect the charge on amino acids and potentially influence their transport mechanisms, increasing or decreasing uptake depending on the cell's requirements and the specific transporters involved.