The buffer systems functioning in blood plasma include plasma proteins, phosphate, and bicarbonate and carbonic acid buffers. The kidneys help control acid-base balance by excreting hydrogen ions and generating bicarbonate that helps maintain blood plasma pH within a normal range.
The answer is "it begins releasing the enzymes to break down large molecules
I haven't taken biology since my freshman year of high school, so this is kind of a guess. But I know for sure it isn't a solid. So I would go with a gas.
