Biosynthetic Pathways Flashcards
If a normal biosynthetic pathway is blocked, the organism can often use the reverse of the degradation pathway for synthesis
Flexibility
This disturbs a system at dynamic equilibrium and shifts the equilibrium in the direction that counteracts the change
Le Chatelier’s Principle
Increasing reactant concentration
favors product formation (shifts right)
Increasing product concentration
favors reactant formation (shifts left)
Increasing temperature
favors endothermic (cold) reaction
Decreasing temperature
favors exothermic (hot) reaction
Increasing pressure
favors the side with less molecule
Decreasing pressure
favors the side with more molecules
What takes place in the conversion of CO2 to carbohydrates in plants?
Photosynthesis
Synthesis of glucose from non-carbohydrate sources
Glucogenesis
What kind of sources are pyruvate, citric acid cycle intermediates, and glucogenic amino acids?
Non-carbohydrate sources
T or F: Glucogenesis is the not the exact reversal of glucogenesis
True
What are the irreversible steps in glycolysis?
- Phosphoenolpyruvate + ADP to pyruvate + ATP
- Fructose 6-phosphate to fructose 1,6-biphosphate
- Glucose to glucose 6-phosphate
Steps in Glucogenesis? (after pyruvate)
- Oxaloacetate
- Phosphoenolpyruvate
- Fructose 1,6-biphosphate
- Fructose 6-phosphate
- Glucose 6-phosphate
- Glucose
Converted to other hexoses and to di-, oligo-, and polysaccharides
Glucose
Activation of glucose by Uridine Triphosphate (UTP) forms?
Uridine Diphosphate Glucose (UDP-glucose) + Pi
Where does lactate from glycolysis in muscle is transported to?
Liver
T or F: Glucogenesis converts lactate back to glucose in the cori cycle
True
Synthesis of glycogen from glucose
Glucogenesis
Where does the DEGRADATION of fatty acids take place?
Mitochondria
Where does majority of fatty acids SYNTHESIS take place?
Cytosol
The end product of each spiral of b-oxidation
Acetyl COA
Fatty acids are synthesized ___ atoms?
2
What is the multienzyme complex in fatty acid synthesis?
Acyl carrier protein (ACP-SH)
T or F: ACP has a side chain that carries the growing fatty acid
True
T or F: ACP rotates clockwise
False - counterclockwise
Steps in Fatty Acid Biosynthesis
- Conversion to acetyl-ACP
- Conversion to acetyl-synthase intermediate
- Conversion to acetoacetyl-ACP
- Conversion to butyryl-ACP
- Conversion to hexanoyl-ACP
- Conversion to plamitic acid
- Conversion to stearic acid (for additional carbon fragment)
What are the 2 building blocks for the synthesis of membrane lipids?
- Acyl COA derivatives
- Glycerol 1-phosphate
What is obtained during the reduction of dihydroxyacetone phosphate?
Glycerol 1-phosphate
What is the product when Acyl COA and Glycerol 1-phosphate is combined?
Phosphatidate
An activated serine, choline, or ethanolamine is added to the phosphatidate by formation of a ____________?
Phosphoric ester
Steps in Cholesterol Synthesis (after 3 moles of Acetyl-COA)
- Conversion to 3-hydroxy-3-methylglutaryl-CoA
- Conversion to mevalonate
- Conversion to isopentenyl pyrophosphate
- Conversion to geranyl pyrophosphate
- Conversion to farnesyl pyrophosphate
Isopentyl pyrophosphateis the key building block of?
- Steriods
- Bile acids
What is the building block for the synthesis of geranyl pyrophosphate (C10) and farnesyl pyrophosphate (C15)?
Isopentenyl pyrophosphate
Serves as an intermediate in the synthesis of several amino acids
Glutamate
Synthesis of several amino acids by the transfer of its amino group is called?
Transamination
