Correct Answers
T/F Under physiological conditions, a catabolic pathway will run backwards when there is a high
concentration of ATP. - Correct Answer False
T/F ATP is the energy currency of the cell. - Correct Answer True
Which one of the following statements is correct regarding metabolic pathways? - Correct Answer
Metabolic pathways always end at a specific molecule.
_______ is a bidirectional glucose transporter. - Correct Answer GLUT2
The glycolytic enzyme that is responsible for trapping glucose in a skeletal muscle cell is _______. -
Correct Answer Hexokinase
The most important regulatory step of glycolysis is ______. - Correct Answer Phosphofructokinase-1
T/F Pyruvate kinase is the only step of glycolysis that is regulated and generates ATP. - Correct Answer
True
The most important regulatory step of gluconeogenesis is __________. - Correct Answer Fructose-
1,6-bisphosphatase
The gluconeogenesis enzyme found in the endoplasmic reticulum is ______________. - Correct
Answer Glucose-6-phosphatase
T/F Adipose tissue is capable of complete gluconeogenesis (i.e. can synthesize glucose). - Correct
Answer False
T/F The liver is the major site of gluconeogenesis. - Correct Answer True
Glycogen synthase: - Correct Answer Is the required site of glycogenesis.
Glycogenolysis: - Correct Answer Involves the synthesis of new a(1->4) linkages.
,T/F a-amylase and isomaltase are required for the breakdown of dietary glycogen - Correct Answer
True
In glycogen metabolism, the branching enzyme: - Correct Answer Synthesizes all a(1->6) linkages.
Glucose-6-phosphate is not involved in the regulation of: - Correct Answer Glucokinase
T/F Insulin increases pyruvate kinase activity and decreases the activity of phosphoenolpyruvate
carboxykinase. - Correct Answer False
Fructose-2,6-bisphosphate: - Correct Answer Activates glycolysis via phosphofructokinase-1 while
inactivating glycogenolysis via fructose-1,6-bisphosphatase
In skeletal muscles, glycogen synthase: - Correct Answer Is always active when not phosphorylated
Pyruvate dehydrogenase is NOT regulated by: - Correct Answer Glucagon
The major regulated step in the TCA cycle is: - Correct Answer Citrate synthase
Lactate dehydrogenase: - Correct Answer Replenishes NAD+ so that the glycolytic enzyme
glyceraldehyde-3-phosphate dehydrogenase can continue to run
T/F The entire Tricarboxylic Acid Cycle (or Krebs cycle or TCA cycle) is found in the mitochondria. -
Correct Answer True
How many electrons can Cyt C carry? - Correct Answer 1
When 3 electrons are transferred onto oxygen (O2), the result is: - Correct Answer hydroxyl radical
T/F Complex I is both a flavoprotein and cytochrome - Correct Answer False
, In the liver, cytosolic electrons are transported into the respiratory chain via: - Correct Answer
Malate/aspartate shuttle
The site of ATP synthesis in Complex V (or ATP synthase or F0F1 complex) is: - Correct Answer aB-
subunits
T/F Phosphate translocase may transport a proton (H+) into the mitochondrial matrix. - Correct
Answer True
Which one of the following is not a proton pump? - Correct Answer Complex II
T/F Lipoprotein lipase is the only lipase in humans that can cleave all three fatty acids off of the
glycerol backbone. - Correct Answer True
T/F Triacylglycerols are slightly amphipathic. - Correct Answer False
Triacylglycerols that are synthesized in the liver are packaged into: - Correct Answer Very low density
lipoproteins
Dietary cholesterol is transported to and processed in: - Correct Answer Liver
T/F Adipose triglyceride lipase is the rate limiting step of lipolysis (fat mobilization). - Correct Answer
True
The regulated step of beta-oxidation is: - Correct Answer Carnitine acyltransferase I
During beta-oxidation, cis-unsaturated fatty acids generate less energy than saturated fatty acids
because: - Correct Answer There is no net gain of electrons during the FAD-dependent oxidation step
when double bonds are present.
Synthesis of a fatty acid via megasynthase requires _____ NADPH. - Correct Answer 14