Chapter 27 (PBL) Pentose Phosphate Pathway

Question 1

What is the overall equation for the conversion of glucose 6-P to fructose 6-P and glyceraldehyde3-P in the pentose phosphate pathway?

Answer 1

3 Glucose 6-P + 6 NADP+ → 3 CO2 + 6 NADPH + 6 H+ + 2 fructose 6-P + glyceraldehyde 3-P

Question 2

What are glycoproteins?

Answer 2

carbohydrate chain attached to a protein

Question 3

What are glycolipids?

Answer 3

carbohydrate chain attached to lipids

Question 4

Where are glycoproteins found?

Answer 4

Found in mucus, blood, compartments w/in cell (e.g. lysosomes) in ECM, and embedded in cell membrane w/ carb portion in extracellular space

Question 5

Where are glycolipids founds?

Answer 5

Found in cell membrane w/ carb portion extruding from cell surface

Question 6

What does the pentose phosphate pathway bypass and what does it generate in general?

Answer 6

Bypasses the 1st state of glycolysis.

Generates NADPH and ribose 5-P

Question 7

What does the oxidative (1st) stage of the pentose phosphate pathway generate?

Answer 7

2 mol of NADPH per mole of glucose 6-P oxidized

Question 8

What does the non-oxidative stage of the pentose phosphate pathway generate?

Answer 8

Generates ribose 5-P and converts unused intermediates to fructose 6-P and glyceraldehyde 3-P in glycolytic pathway

Question 9

Why is the entry of glucose 6-P into the pentose phosphate pathway controlled by the concentration of NADPH?

Answer 9

NADPH is a strong inhibitor of glucose 6-P dehydrogenase and glucose 6-P dehydrogenase hydrolyzed glucose 6-phosphate, resulting in the creation of a phosphate group and free glucose

Question 10

In the liver what is the major route of NADPH reoxidation?

Answer 10

Synthesis of fatty acids from glucose in the liver is the major route of NADPH reoxidation