Question

3. How does chirality and shape affect biochemical reactions

4. A bacteria is native to the peat bogs of Ireland which have a pH less than 5. Knowing this, do you think the bacteria would thrive as a human pathogen (note that blood pH is ~7.4)? Why?

5. Draw the peptide HEAR.

Answer 1

3.

Most of the metabolic reactions in our body are catalyzed by enzymes.

Chirality and shape of a compound are major determinants in an enzyme-catalyzed reaction.

The active site of most of the enzymes is complementary to the shape of its substrate so they can fit in properly.

If the chirality or the shape changes, the compound is no longer recognized by the enzyme for catalysis.

Ex: Ribosomes recognize L-amino acids and glycosidase recognizes only D-sugars in our body.

4.

No.

The bacteria is very unlikely to survive in our blood due to pH difference.

However, most pathogens have evolved special adaptations such as thick walls to sustain harsh conditions encountered in the host.

5.

See image.