lec2 glycolysis Flashcards
the only metabolite that begins its digestion from the mouth is…….
CHO
the CHO is digested in the mouth via………. enzyme
a-amylase enzyme
the a-amylase enzyme breaks …………. resulting in a mixture of ……….. and ………
a(1>4)bonds of starch
short branched and unbranched oligosaccharides (dextrin)
Humans can not digest cellulose. Why?
Salivary β-amylase that breaks β glycosidic
bonds are not found in humans, therefore humans
cannot digest cellulose.
there is No digestion of carbohydrates In the stomach why?
because high acidity inactivates salivary amylase.
……..it is an enzyme continues the digestion of CHO
Pancreatic α-amylase
The final digestive processes occur at………….
jejunum
write a short note about lactose intolerance.
due to genetic lactase deficiency.
Any deficiency in disaccharides activity of intestinal mucosa causes passage of undigested CHO into large intestine causing osmotic diarrhea→ bacterial fermentation of CHO to 2 or 3-carbon compounds + CO2 + H2 gas→ abdominal cramps and flatulence.
Treatment: remove lactose and give lactase pills, Eating yoghurts, cheeses and green vegetables to ensure adequate calcium intake.
Glycolysis means…………….
oxidation of glucose to give pyruvate (in the presence of oxygen) or lactate (in the absence of oxygen)
the glycolysis occurs in …….
cytosol
the end product of the 1st step in glycolysis is……
glucose 6-phosphate
the 1st step in glycolysis is a reversible state
T or F?
F
irreversible
the initial substrate in 1st step is…….
glucose
the enzyme used in 1st step is ………
kinase enzyme (hexokinase or glucokinase)
write a short note about 1st step
Phosphorylation of glucose into glucose 6-phosphate, using an ATP and a kinase enzyme (glucokinase or hexokinase),
(Irreversible step).
the 2nd step is the irreversible step
T or F?
F reversible
the initial substrate in the 2nd step is…….
glucose 6-phosphate
the enzyme used in the 2nd step is………
phosphohexose isomerase
the product in the 2nd step is……
fructose 6-phosphate
write a short note about the 2nd step
Isomerization of glucose 6-phosphate into fructose 6-
phosphate by phosphohexose isomerase (reversible step).
the 3rd step is the irreversible step
T or F?
T
the initial substrate in the 3rd step is…….
fructose 6-phosphate
the product in the 3rd step is……
fructose1,6 -bisphosphate
the enzyme used in the 3rd step is………
phosphofructokinase-1
