Metabolic_Perspective_Flashcards_Brainscape
(26 cards)
What are the major fuel molecules and their storage forms?
Carbohydrates - Glucose (stored as Glycogen), Lipids - Fatty acids (stored as Triglyceride), Amino acids - stored as Protein.
What is the principal cellular process for ATP generation?
The TCA cycle.
How is phosphofructokinase (PFK) regulated?
Stimulated by AMP, inhibited by ATP.
What is AMPK and its function?
AMP-activated protein kinase; senses cellular energy status and regulates metabolism.
How does the liver uptake and release glucose?
Via GLUT-2 transporter; phosphorylates glucose with glucokinase, stores as glycogen or metabolizes.
How does insulin affect liver carbohydrate metabolism?
Stimulates glucose uptake and storage as glycogen, inhibits glycogen breakdown.
How does glucagon affect liver carbohydrate metabolism?
Stimulates glycogen breakdown and gluconeogenesis.
What maintains glucose homeostasis?
Insulin and glucagon regulate blood glucose, maintaining it between 4-5 mM.
What are the roles of the liver in amino acid metabolism?
Takes up AAs, uses them for glucose/FA/ketone synthesis, provides 50% of its energy.
What are glucogenic vs ketogenic amino acids?
Glucogenic AAs are used to make glucose; ketogenic AAs make ketone bodies.
What happens to fatty acids in the liver?
Oxidized for energy or converted to triglycerides for storage/VLDL export.
How is CPT-1 regulated?
Inhibited by malonyl CoA (fed state); activated by glucagon (fasted state).
What is the primary metabolic role of adipocytes?
Store triglycerides and release free FAs during fasting.
How does insulin affect adipose tissue?
Stimulates TG storage and inhibits lipolysis.
How does adrenaline affect adipose tissue?
Stimulates TG lipase and lipolysis.
What fuels does muscle use at rest?
Fatty acids and ketone bodies.
What fuels does muscle use during intense exercise?
Glycogen (via glycolysis), producing lactate.
What is the role of phosphocreatine in muscle?
Acts as a buffer to rapidly regenerate ATP.
What fuels can the brain use?
Primarily glucose; uses ketone bodies during prolonged fasting.
What are the main fuel stores in the body?
Fat (550 MJ), Protein (210 MJ), Glycogen (7.65 MJ), Free Glucose (0.2 MJ).
What is the adaptation during prolonged starvation?
Protein loss minimized, brain uses ketone bodies, gluconeogenesis from AA/lactate.
Why can’t the liver use ketone bodies?
It lacks β-ketoacyl-CoA transferase.
What are the symptoms of Type 1 Diabetes?
Lethargy, thirst, excessive urination, weight loss.
What are the metabolic consequences of insulin deficiency?
Hyperglycemia, ketonemia, weight loss, acidosis.
