Principles and Design of Metabolism Flashcards
What is the function and metabolic capacity of skeletal muscles?
mechanical work, fuels protein degradation for ATP synthesis. White muscles fibers: contract rapidly, have limited duration, high capacity, limited aerobic oxidation (low mitochondria count), glycogen and glucose breakdown with lactate formation
Red muscle fibers: slower contracting, higher oxidative capacity, high mitochondria count
What is the function and metabolic capacity of heart?
continuous contracting, high oxidative capacitym highest density of mitochondria
What is the function and metabolic capacity of liver?
biosynthetic and detox, rich in mitochondria, store glucose as glycogen, de novo glucose synthesis, urea synthesis, ketone synthesis, assemble lipoproteins, fuel homeostasis
What is the function and metabolic capacity of brain and nerves
ion pumping - maintain membrane potential for electrical activity. high glycolytic and oxidative capacity, major fuel: glucose, can adapt to use ketones, not fatty acids
What is the function and metabolic capacity of adipose tissue
storage, mobilization and synthesis of triglycerides
What is the function and metabolic capacity of kidney?
fluid homeostasis, osmotic work, active transport, acid and base balance, uses fatty acids, lactate, and ketons for fuel, ammonia synthesis and gluconeogenesis possible
What is the function and metabolic capacity of red blood cells?
exchange O2 and CO2. no mitochondria, anaerobic glycolysis, makes 2,3BPG to regulate O2 affinity of hemoglobin
What is the function and metabolic capacity of GI tract
nutrients digested by enzymes and absorbed via membrane transporters
What pathways take place in the cytosol only?
glycolysis, pentose phosphate pathway, fatty acid synthesis, nucleotide synthesis, protein synthesis
What pathways take place in the mitochondria only?
TCA, oxidative phosphorylation, beta-oxidation of fatty acids, ketogenesis and ketone oxidation
What pathways use both cytosolic and mitochondrial enzymes?
gluconeogenesis, urea synthesis, steroid hormone synthesis
What pathways take place in smooth ER?
triglyceride synthesis, phospholipid synthesis, cholesterol synthesis, hydroxylation and detoxification reactions (cytochrome p450)
What are the properties of a protein kinase?
transfer phosphate from the gamma position on ATP to hydroxyl group of serine, threonine, tyrosine, to form phosphate ester linkage
What are the properties of a protein phosphatase?
hydrolyze phosphate ester and return protein/enzyme to dephosphorylated form
What does phosphorylation do to an enzyme in the catabolic pathway?
activate it
What does phosphorylation do to an ezyme in the anabolic pathway?
inhibit it
what is creatine phosphate?
its a storage form used in muscles
How many high energy molecules are formed in glycolysis, TCA, fatty acid oxidation, oxidative phosphorylation?
glycolysis - 2 ATP, 2 NADH
TCA - 1 GTP, 3 NADH, 1 FADH2
Fatty acid oxidation- 1 NADH, 1 FADH2
Oidative phosphorylation: for each NADH - 3 (2.5) ATP, for each FADH2: 2 (1.5) ATP
What do dehydrogenases do?
catalyze transfer of hydrogen from substrate to coenzyme acceptor
What are the differences between NAD+ and NADP+
NADP+ has additional phosphate group
NAD+ primary catabolic and oxidative
NADP+ primarily anabolic, reductive
NAD mostly mitochondria NADP mostly cytosol
What do oxidases do?
they catalyze oxidation/reduction reactions, transfer electrons from some organic substrate to molecular oxygen via an intermediate carrier (like metal ions or flavin nucleotides (FMN or FAD)) Oxygen reduced to water or hydrogen peroxide.
What do oxygenases do?
catalyze incorporation of molecular oxygen into organic substrates
describe the effects of peroxidases and catalases?
peroxidases - reduce hydrogen peroxide to H2O
catalases- catalyse the dimutation of hydrogen peroxide to H2O and O2
