bio 一問~~~

1. Denature proteins can still be digested by ACTIVE enzyme.

Normally, proteins are maintained in their active conformation (shape) by the weak interaction among the amino acids (molecules inside the proteins).
Denature means that the weak interaction is broken down so the protein cannot maintain its ACTIVE conformation, but the amino acid is still bound to each other if the denature force is not vigorous (like pH change)

Protein digestion means that the peptide bonds among the amino acids is broken down.

Whether the proteins can be digested or not, it really depends on whether the Enzymes (protease/ peptidase) are active or not.

2. The absorption of glucose depends on the amount and the activity of the glucose transporter on the surface of the stomach. (The transporter is called GLUT 4). Since there are limitation of the efficiency of the glucose transport, not all the glucose can be absorbed in small intestine when the glucose intake are TOO HIGH.

2007-04-09 12:37:22 補充：
手快打錯左...應該係small intestine 先岩
glucose transporter on the surface of the "small intestine"

1. Your liver will secrete pancreatic juice and bile to break it down
2.No because the total cross-saction area of the small intestine is limited
therefore not all the glucose can be absorbed.

Firstly want to clearify that protein may or may not be denatured by HCl. Some protein with high resistance to acid will not be denatured (Such as protease which work in acidic media in lower pH). But most of them are digested by gastric juice (which contain protease) produced by stomach in Islets of Langerhans and goblet cell.
Have a look [http://en.wikipedia.org/wiki/Stomach]

A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain.

As a reslut the active site of protease is independent to the denatured protein as each proten contain peptide bonds


The second question... Too stupid.
The answer is no.

2007-04-05 21:01:25 補充：
話明 pancreatic juice 梗係pancrease 做嫁la liver 只會做 Bile juice 唔做 ancreatic juice 嫁