Metabolism Flashcards
Which glycogen storage disease has glycogen phosphorylase deficiency?
Type 5 (McArdle’s disease)
Which glycogen storage disease has glucose-6-phosphatase deficiency?
Type 1 (Von Gierke’s disease)
Which glycogen storage disease has lactic acidosis, hyperlipidemia, hyperuricemia?
Type 1 (Von Gierke’s disease)
Which glycogen storage disease has alpha-1,6-glucosidase deficiency?
Type 3 (Cori’s disease)
Which glycogen storage disease has an alpha-1,4-glucosidase deficiency?
Type 2 (Pompe’s disease)
Which glycogen storage disease has cardiomegaly?
Type 2 (Pompe’s disease) infantile type
Which glycogen storage disease has diaphragm weakness -> respiratory failure?
Type 2 (Pompe’s disease) adult type
Which glycogen storage disease has increased glycogen in the liver, sever fasting hypoglycemia?
Type 1 (Von Gierke’s disease)
Which glycogen storage disease has hepatomegaly, hypoglycemia, hyperlipidemia (normal kidneys, lactate, and uric acid)
Type 3 (Cori’s disease)
Which glycogen storage disease has painful muscle cramps, myoglobinuria with strenuous exercise?
Type 5 (McArdle’s disease)
Which glycogen storage disease has severe hepatosplenomegaly and enlarged kidneys?
Type 1 (Von Gierke’s disease)
What fuels are produced and used in the post absorptive period?
Glucose from liver glycogenolysis/ gluconeogenesis b/c there is no glucose left from your meal anymore.
Fatty acids from adipose tissue.
Brain, muscles and other tissue predominantly use glucose.
When does gluconeogenesis begin in the post-absorptive period? When does it become fully active?
Begins 4-6 hours after last meals.
Fully active when glycogen stores are depleted (10-18 hours after last meal).
How does the pattern of fuel production and usage change in early starvation (24 hours after last meal)?
Mainly gluconeogenesis (possibly a small amount of glycogenolysis).
Fatty acids from adipose tissue.
Brain predominantly uses glucose. Muscles and other tissues use some glucose some glucose but predominanly fatty acids. Brain and RBCs hog the glucose.
In intermediate starvation (48 hours after the last meal) how does the pattern of fuel production and consumption change?
Produced: glucose from liver gluconeogenesis, fatty acids from adipose tissue, ketone bodies from the liver.
Used: brain uses predominantly glucose but also some ketone bodies. Muscles and other tissues use predominantly fatty acids but also some glucose and ketone bodies.
What metabolic scenario favors the synthesis of ketone bodies?
Excess of acetyl CoA from fatty acid metabolism. When there is so much acetly CoA that it cant go thru TCA cycle, the rest of it will be broken down to ketone bodies.
True or false. The ketone bodies can be used by all body tissues including the brain?
False. RBCs need glucose, everything else can use ketone bodies.
What is the pattern of fuel utilization and production in prolonged starvation (5 days after last meal)?
Produced: glucose from liver gluconeogenesis, fatty acids from adipose tissue, ketone bodies from the liver.
Used: Brain uses predominantly ketone bodies. Muscles and other tissues use predominantly fatty acids and some ketone bodies. Whatever glucose is left will be used by RBCs.
Comparing an overnight fast to a 3 day fast, what percentage of energy comes from glucose and from ketone bodies?
Overnight: 95% from glucose (2/3 from glycogen breakdown, 1/3 from gluconeogenesis). 5% from ketone bodies.
3 day fast: 60% from ketone bodies (1/2 are betahydroxybutarate, 1/2 acetoacetate). 40% from glucose (most from gluconeogenesis).
What are the major regulatory enzymes of the citric acid cycle?
Citrate synthase (1st step), isocitrate dehydrogenase (rate limiting step). Alpha ketogluterate dehydrogenase (heavily regulate. Requires lots of coenzymes -> Tender loving care for nobody = Thiamine/ TPP, Lipoic acid, CoA, FAD, NAD)
What is the rate limiting enzyme for glycolysis?
PFK1 (phosphofructokinase)
What is the rate limiting enzyme for gluconeogenesis?
Fructose-1,6-bisphosphatase
What is the rate limiting enzyme for citric acid cycle?
Isocitrate dehydrogenase
What is the rate limiting enzyme for glycogenesis
Glycogen synthase
What is the rate limiting enzyme for glycogenolysis?
Glycogen phosphorylase
What is the functional role of S-adenosyl-methionine?
Transfers methyl (-CH3) groups. Used in the generation of phosphocreatine. Also important in the tetrahydrofolate, folic acid pathway. SAM is the methyl donor man. We use ATP and methionine to make SAM.