Question

Glycolysis is an example of a metabolic pathway that is utilized by all human body tissues. Other pathways are much more prominent in, or nearly absent from, certain tissues. For example, glycogenesis is prominent in liver and muscle tissues but not in brain tissue. Tissue‑specific metabolism is often due to a large difference in the amount of a key pathway enzyme between tissues.
For each statement, determine the tissue in which the pathway enzyme is most prominent.
1. Glucokinase, an isozyme of hexokinase, phosphorylates glucose in this tissue ___________.
2. Glucose-6-phosphatase is only found in this tissue, where it hydrolyzes glucose-6- phosphate and releases glucose into the blood _____.
3. Creatine kinase regenerates ATP from ADP in this high energy demand tissue_________.
4. Lipases hydrolyze triacylglycerols in this tissue, releasing fatty acids into the blood__________.
5. β- ketoacyl-CoA transferase (thiophorase) is absent from this tissue_________.

Answer 1

Answer:

1. Liver

2. Liver and Kidneys

3. Mitochondria

4. Lumen of the small intestines

5. Liver

Explanation:

1. Glucose is phosphorylated into glucose-6-phosphate which is the first step of both glycogen synthesis and glycolysis, this process occurs in the liver

2.   Glucose 6-phosphate is a product of a process named gluconeogenesis which occurs in the liver it serves as a substrate for glucose-6-phosphatase in the liver.

3. Creatinine kinase is an enzyme that catalyzes the phosphorylation of creatine. In regeneration process of ATP, creatine phosphate transfers a high-energy phosphate to ADP which produces ATP and creatine

4. Initially lipase digestion lipase digestion happens in the small intestine where the bile salts reduce the surface tension of the fat droplets allowing the lipases to attack the triglyceride molecules. These molecules are taken up into the epithelial cells that line the intestinal wall, where they are resynthesized into triglyceride

5. The job of the liver is to produce ketone bodies. If the liver had this enzyme, the ketone bodies it produces would be immediately broken down by the liver before they are released, thereofore, no release of ketone bodies into the bloodstream