Lecture 17 Flashcards
importance of glucose
excellent fuel
versatile biochemical precursor
storage
energy production
production of NADPH and pentoses
structural carb production
in the first five steps of glycolysis, one six-carbon molecule of glucose is split into _____ _____ carbon compounds
two 3 carbon compounds
how many molecules of ATP required for glycoslysis initial steps
2
in glycolysis d-glucose-6-phosphate is turned form the _____ to the _____ dorm
aldo to keto
what do glucokinase and hexokinase do
enzymes that catalyze phosphorylation of glucose to glucose-6-phosphate
is glucokinase or hexokinase inhibited by glucose 6-phosphate
glucokinase
does glucokinase or hexokinase have a higher affinity for glucose
hexokinase
is glucokinase or hexokinase only present in liver and pancreas B cells
glucokinase
phase 2 of glycolysis
glyceraldehyde-3-phosphate converted to pyruvate
how many molecules of ATP produced by phase 2 of glycolysis
4 ATP, 2 for each molecule of pyruvate produced
3 fates of pyruvate
- TCA cycle
- anaerobic glyclysis in contracting muscle
- alcoholic fermentation in yeast
what do peroxisomes have to do with alcohol metabolism
contain catalase, which converts ethanol to acetaldehyde
end state of alcohol metabolism
acetyl coa
can alcohol metabolism acetyl coa go into the tca cycle
no
what are alcohol metabolism acetyl coa used for
fatty acid synthesis
how is fructose metabolized in most cells
same way as glucose
in liver cells, what cannot work on fructose
glycokinase
what is used to convert fructose into fructose-1-phosphate
fructokinase
what can fructose-1-phosphate be converted into
intermediates of glycolysis and TCA cycle
can fructose be stored?
no, it cannot be stored as glycogen
what happens to fructose when ATP pool is saturated
assembled as fat
where does fructokinase put the phosphate
the first carbon, not the sixth, making fructose-1-phosphate
consequences of a high-fructose diet
elevated triglycerides
fatty liver
increased fat storage
leptin insensitivity
