4.1.1 Integrative Metabolism I Flashcards
Describe how tryptophan can be converted to melatonin
Describe the other recycling pathway b/t the liver and muscle.
What is the key control enzyme in glycolysis?
Phosphofructokinase
What is used in the glycogen synthesis? What is required?
Branching enzymes; UDP-glucose and a primer
Glycogen is what type of storage?
Short-term; Used in glycolysis and oxidative metabolism
What are some of the branchpoints off of pyruvate and acetyl CoA?
What is the main control factor of the pentose phosphate pathway?
Concentration of NADP+
Answer
B. Glucose
What are some of the activators/stimulators/inhibitors of acetyl CoA carboxylase?
Activator: Citrate
Stimulator: Insulin
Inhibitors: Glucagon and Palmitoyl CoA
What are two key branch points in the urea cycle?
Arginine and Ornithine
What is the key control enzyme in fatty acid synthesis?
Acetyl CoA Carboxylase
What type of reaction is used to remove glucose off of glycogen?
Phosphorolysis
Describe the process through which glucose can lead to the generation of ketone bodies
How do debranching enzymes work?
How/where are carbohydrates stored within the human body?
Glycogen - Liver, Muscle
Glucose - Extracellular
Describe when these enzymes (glycogen synthase, phosphorylase, phosphorylase kinase, protein phosphatase-1 inhibitor) are activated or inactivated?
Where does the debranching enzyme begin working on glycogen?
Begins at the non-reduced ends
Answer
The pentose phosphate cycle
What are the 7 principles of metabolic regulation?
- Substrate supply
- Allosteric interactions
- Covalent modifications
- Enzyme levels
- Compartmentation
- Organ specialization
- Endocrine controls
What is a key control step (enzyme) in gluconeogenesis?
Fructose-1,6-Bisphosphatase
What are some of the uniftying themes in intermediary metabolsim?
Describe the circular steps of the TCA cycle
Describe the step-wise pathways of glycolysis/gluconeogenesis b/t glucose and pyruvate.
What is glycogen?
A highly-branched structure with (1-6) branches occuring every 4th residue
Describe the conversion of tyrosine to epinephrine
Describe the pattern of liver glycogen content over a 24 hr period
Varies
Electron donor in reductive synthetic reactions?
NADPH
What enzyme aids in the conversion of tyrosine to thyroxine (T4)? What does this enzyme require?
Thyriod peroxidase; H2O2
Electron acceptor in oxidative degradative reactions
NAD+
What are the three main compartments in cells?
Mitochondrial matrix
Cytosol
Interplay of both compartments
Answer
Fructose-1,6-Bisphosphatase
What are some of the activators/inhibitors/stimulators of Fructose-1,6-bisphospatase?
Activator: Citrate
Inhibitors: AMP, F-2,6-BP, Insulin
Stimulators: Glucagon, cortisol
Describe what metabolic pathways occur in the following compartments: Mitochondrial matrix, cytosol, both.
Answer
C. Acetyl CoA Carboxylase
What are some activators/inhibitors of phosphofructokinase?
Activators: F-2,6-BP, AMP
Inhibitors: ATP and citrate
What enzyme converts T4 to T3
5’-deiodinase
Answer
B. Phosphofructokinase 1
What are the key metabolic branch points of glucose metabolism
Describe the recycling pathway that exists b/t the liver and muscle. What is this cycle known as?
Cori Cycle
What reaction must occur in the liver for it to leave the tissue and enter the blood?
The bottom reaction
Summarize the urea cycle
What is an important enzyme in the pentose phosphate pathway?
