Review of Metabolism Flashcards
(25 cards)
What are the three main fates of consumed glucose?
Oxidation for energy
Synthesis of many compounds
Storage in glycogen and TAG
What is the caloric content of glucose per gram? Fatty acids? Protein?
Glucose: 4 kcal/g
Fatty acids: 9 kcal/g
Protein: 4 kcal/g
What are the three main fates of consumed amino acids?
Oxidation for energy
Protein synthesis
Synthesis of nitrogen containing compounds
What are the three main fates of consumed fatty acids?
Synthesis of membrane lipids
Beta oxidation for energy
Storage in adipose as TAG
What does insulin levels do to glucagon?
Higher levels inhibit release of glucagon
What hormones will be released from a high protein diet?
High glucagon, low insulin
What hormones will be released from a high carb meal?
Lots of insulin, low glucagon
What two pathways are activated by the insulin receptor?
MAPkinase and protein phosphorylase 1
What types of cells release glucagon?
Pancreatic alpha cells
How does the brain respond to being in the fed state? Fasted?
Oxidizes glucose through oxidative phosphorylation
Uses glucose and ketone bodies for the TCA cycle
How do red blood cells respond to a fed, fasted, or starved state?
ALWAYS glucose fermentation to pyruvate and lactate
How do white fat cells react to the fed state? Fasted state?
Ferments glucose to glycerol 3 phosphate, the backbone for TAG synthesis
Fasted: Lipolysis of triacylglycerol produces fatty acids for use in liver and cardiac muscle. Also releases glycerol for liver gluconeogenesis
How do skeletal muscles react to being in the fed state? Fasted?
Fed: Glycolysis, fatty acid metabolism, glycogenogenesis, protein synthesis
Fasted: Proteolysis produces amino acids. Branched chain amino acids are used for fuel. Alanine/glutamine transported to liver for gluconeogenesis
How do cardiac muscle react to being in the fed state? Fasted?
Fatty acid beta oxidation (60-80%)
Glucose metabolism (20-40%)
Fasted: Fatty acid comsumption increases, glucose decreases
What three things are converted to alpha ketoglutarate by the intestinal epithelial cells during the fast state?
Glutamine, glutamate, aspartate
What do coloncytes do in the fasted state?
Use short term fatty acids produced by gut bacteria
How long after eating is considered the fasted state?
4-24 hours
Where does the intestinal epithelium primary source of glutamine come from during the fasted state?
Blood, proteolysis
What molecule becomes the predominant fuel source in the prolonged fast state?
ketone bodies
What are some things that would cause a hypercatabolic state?
Trauma, sepsis, rapid blood loss, burns, surgery
What is epinephrine’s role in the hypercatabolic state?
Activates epinephrine sensitive lipase, mobilize fat from adipose tissue
What is cortisol’s role in a hypercatabolic state?
Activates proteolytic activity in muscles, increases amino acid mobilization
What is glucagon’s role in hypercatabolism?
Activates hepatic glycogenolysis and gluconeogenesis
What is the equation for nitrogen balance?
Nitrogen balance = Consumed Nitrogen - (Urine Urea Nitrogen Level + 2)
