Carbohydrates and Glycolysis Flashcards
All monosaccharides contain a _______ group.
Carbonyl.
What are the two possible carbonyl groups for a monosaccharide?
Ketone or aldehyde.
Which enantiomer is found in nature - D or L glucose?
D-glucose.
Which is more common - beta-D-glucose or alpha-D-glucose?
Beta-D-glucose.
What is sucrose made of?
A glucose and a fructose.
_________ is a branched form of _________.
Amylopectin is a branched form of amylose.
Starch is generally 25% ______ and 75% _______.
25% amylose, 75% amylopectin.
What is the polymerised version of glucose used for storage called?
Glycogen.
Where is glycogen stored?
Muscle and liver cells.
What is a homopolysaccharide?
Formed by at least 6 identical monosaccharides.
In a low energy state, a cell has a lot of ADP and low ATP. True or false?
True.
What accumulates at a very low energy state?
AMP.
What enzyme catalyses glycolysis to leave a low energy state?
Phosphofructokinase.
Is phosphofructokinase activated by AMP or ATP?
AMP.
Are glucose transporters always at the membrane or stored in vesicles?
Vesicles.
Phosphofructokinase has a _______ feedback loop - one of its products, fructose-2,6-bisphosphate, _________ enhances phosphofructokinase.
Positive, allosterically.
Which one inhibits phosphofructokinase - ADP or ATP?
ATP.
Is glucokinase only found in liver cells?
Yes.
What is the end product of hexokinase and glucokinase?
Glucose-6-phosphate.
Glucokinase has ____ affinity for glucose so that it only traps excess to store as glycogen.
Low.
In aerobic cells with mitochondria, how is NAD+ regenerated?
Oxidative phosphorylation.
In anaerobic yeast, what is NAD+ regeneration coupled to?
Ethanol and CO2 production.
In anaerobic skeletal muscle, what is NAD+ regeneration coupled to?
Lactate production.
What is the term for the recycling of lactate to glucose in the liver during exercise?
Gluconeogenesis.
Pyruvate decarboxylation is the first step of which aerobic cycle?
TCA cycle.
Is pyruvate converted into acetyl-CoA in aerobic or anaerobic mitochondrial cells?
Aerobic.
As the first step of the investment phase of glycolysis, what does hexokinase do?
Phosphorylates glucose to trap it in the cell.
What is the result of the preparatory phase of glycolysis?
Two identical cleavage products.
What is the goal of the payoff phase of glycolysis?
Conversion of the cleavage products into pyruvate.
Approximately what percentage of glucose energy is released by glycolysis?
5%.
Can other sugars enter glycolysis?
Yes, but glucose is preferred.
