Lecture 1 - Principles and Design of Metabolism Flashcards
What are the 2 major goals of metabolism?
- Extract energy and reducing power from the environment
2. Synthesize building blocks needed to make more complex polymeric molecules
_________ pathways are:
- generally OXIDATIVE in nature;
- involve breaking covalent bonds;
- result in release of energy
Catabolic (degradative) pathways
Glycolysis and fatty acid oxidation of examples of ______ pathways.
Catabolic pathways
________ pathways are:
- generally reductive in naturel
- involve bond formation between smaller molecules to synthesize larger molecules;
- consume energy
Anabolic (synthetic) pathways
Glycogen synthesis and fatty acid synthesis are examples of _______ pathways.
Anabolic pathways
The pathway of glycogen/glucose to form fatty acids/ketones/acetyl-CoA is called:
A. Lipogenesis
B. Ketogenesis
C. Gluconeogenesis
D. Synthesis of nonessential aa’s
A.
The pathway of glycogen/glucose to form protein/amino acids is called:
A. Lipogenesis
B. Ketogenesis
C. Gluconeogenesis
D. Synthesis of nonessential aa’s
D
The pathway of protein/amino acids to form fatty acids/ketones/acetyl-CoA is called:
A. Lipogenesis
B. Ketogenesis
C. Gluconeogenesis
D. Synthesis of nonessential aa’s
B
The pathway of protein/amino acids to form glycogen/glucose is called:
A. Lipogenesis
B. Ketogenesis
C. Gluconeogenesis
D. Synthesis of nonessential aa’s
C
_____ is a major carrier of electrons in oxidation reactions.
A. ATP
B. NAD+
C. NADPH
D. Coenzyme A
B (FAD is also a major carrier of electrons)
______ is the universal carrier of acyl groups.
A. ATP
B. NAD+
C. NADPH
D. Coenzyme A
D
_______ supplies the reducing power for biosynthetic reactions.
A. ATP
B. NAD+
C. NADPH
D. Coenzyme A
C
Which type of skeletal muscle fibers contract rapidly, have limited duration and high capacity, and utilize glycogen and glucose breakdown with lactate formation?
White muscle fibers
Which type of skeletal muscle fibers have limited aerobic oxidation due to low mitochondria content?
White muscle fibers
Which type of muscle fibers are slower contracting and have a high mitochondria content?
Red muscle fibers
Which type of muscle tissue has the highest density of mitochondria?
A. Skeletal
B. Heart
C. Liver
D. Brain and nerve
B
The _______ plays a primary role in glucose homoestasis and stores glucose as glycogen.
liver
What organ/system has high glycolytic and oxidative capacity, but cannot oxidize fatty acids?
brain/nerves
The _______ carries out ammonia synthesis and gluconeogenesis using fatty acids, lactate, and ketones as fuels.
kidney
The storage form of carbohydrates is:
A. Glycogen B. Triglycerides C. Glucose-6-P D. Pyruvate E. Lactate
A
Which of the following is NOT a storage form of one of the fuel sources?
A. Glycogen
B. Triglycerides
C. Acetyl CoA
D. Protein
C (Acetyl-CoA is a tissue form.)
Which of the following is NOT a circulating form of one of the fuel sources?
A. Amino acids B. Triglycerides C. Fatty acids D. Lactate E. Pyruvate F. Ketones
E (Pyruvate is a tissue form.)
Which is NOT one of the 4 key intermediates, or “branch points” in metabolism?
A. Glucose-6-P B. Oxaloacetate C. Pyruvate D. Acetyl-CoA E. Glutamate
B (Oxaloacetate is an intermediate in the conversion of pyruvate to G6P.)
The 3 priorities in fuel metabolism after a meal are:
- Meet the immediate energy needs
- Replenish glycogen stores
- Store all remaining calories as fat
Stage ____ in extraction of energy is the conversion of building blocks to common intermediates.
A. Stage I
B. Stage II
C. Stage III
D. None of these
B
Terminal oxidation of acetyl-CoA to CO2 and H2O, where most energy is extracted, is which stage in extraction of energy?
A. Stage I
B. Stage II
C. Stage III
D. None of these
C (Note - Stage III occurs in mitochondria.)
Which is NOT a cytosolic pathway?
A. Pentose Phosphate Pathway B. Fatty Acid Synthesis C. Nucleotide Synthesis D. Tricarboxylic Acid Cycle E. Glycolysis
D (TCA Cycle is a mitochondrial pathway)
Which is a pathway that uses both cytosolic and mitochondrial enzymes?
A. Oxidative phosphorylation B. Ketogenesis and ketone oxidation C. Gluconeogenesis D. Glycolysis E. Protein synthesis
C
Which is a pathway that occurs in the smooth endoplasmic reticulum?
A. Triglyceride synthesis B. Fatty acid synthesis C. Nucleotide synthesis D. Protein synthesis E. Urea synthesis
A
Where do ketogenesis and ketone oxidation occur?
A. Cytosolic Pathway
B. Mitochondrial Pathway
C. Both cytosolic and mitochondrial pathways
D. Smooth Endoplasmic Reticulum
B
Where does cholesterol synthesis occur?
A. Cytosolic Pathway
B. Mitochondrial Pathway
C. Both cytosolic and mitochondrial pathways
D. Smooth Endoplasmic Reticulum
D
