Why would the ability to produce extracellular enzymes be a valuable characteris

Question

Why would the ability to produce extracellular enzymes be a valuable characteristic in the microbial world? ___________________ So far during this course you have tested for the presence of three extracellular enzymes, DNase (exercise 36), gelatinase (exercise 37), and amylase (exercise 38). If you were a bacterium and had a choice, which enzyme would you produce (select only one)? Why? ___________________ How do you know amylase is an extracellular enzyme? ___________________ Why is amylase less effective at hydrolyzing amylopectin than at hydrolyzing amylose? ___________________

Explanation / Answer

1. Extracellular enzymes or exoenzymes are enzymes that are secreted by a cell for exerting their functions extracellularly or outside the cell. Bacteria and fungi produce extracellular enzymes to digest the nutrients present in their surrounding environment. These digested products can enter inside the bacteria and power cellular pathways.
The exoenzymes are also used by pathogens (bacteria, fungi etc) to cause diseases. The enzymes are secreted by the pathogen to digest the host cell's protective outer layer and thus help in causing infection.

3. If I was a bacterium, I would produce amylase. Amylase is a hydrolase enzyme and it catalyses the hydrolysis of a-1,4-glycosidic linkages in starch to yeild monosacchrides or disaccharides.

4. We know that amylase is an extracellular enzyme because it is secreted by the cells into the body for digesting starch molecules. In humans, amylase is secreted by the salivary glands and then released in the mouth. It is also secreted by the pacreatic cells and released into the small intestine.

5. Starch is a polysachharide. Its components are amylose and amylopectin. Amylase is a hydrolyting enzyme which breaks down starch into simpler components. Hydrolysing amylopectin is more challenging because it involves a-1,6-glycosidic branch points. Amylase is more specific for a-1,4-glycosidic links than a-1,6-glycosidic links. Thus, amylase is less effective at hydrolysing amylopectin than hydrolysing amylose.

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.