Glucose Flashcards
How much energy does ATP and NADH provide?
ATP = 30.5 kj/mol NADH = 220 kj/mol
What’s the term for breakdown of energy?
catabolism
What does anabolism mean?
build up of energy
How efficient is the metabolic cycle?
~40%
Does ATP travel as free units?
No, they are bound to Mg
What’s the half life of ATP?
~1 min
How is NADP+ different to NAD?
a hydroxyl group is esterified with phosphate
What is NAD used for?
anti-oxidant and high-energy demanding pathways
What is the product of glycolysis?
2 pyruvate, 2 ATP and 2 NADH
How many carbons do monosaccharides have?
3-7 carbons
How is glucose harmful to the body?
it easily reacts with surface proteins, causing problems in the circulation
What happens to blood vessels when they are glycated?
they become brittle and prone to clots. Hence diabetics can become blind
At what level of blood glucose will result in glucose detected in urine
over 10mM
T/F glycolysis is efficient
False, only 2.1% of glucose energy is captured. This is an anaerobic pathway
which substance in the blood can indicate high glucose level in blood?
haemoglobin A1C, the glycosylated RBC
Where does glycolysis occur in a cell? What prevents it from leaking out of the cell membrane?
in the cytosol. It carries phosphate that has a negative charge to prevent leaking
Where can you find these channels?
1) Glut 1
2) Glut 2
1) all cells in the body
2) on the liver and pancreas
What does Glut 4 respond to?
insulin
What happens to the cells of a diabetic
lack of insulin stimulation to cells, so there is high circulating glucose, but the cells are still starving of energy
What is the action of hexokinase?
converts glucose to glucose 6-phosphate while consuming one ATP
What kind of enzyme is hexokinase?
It is a two-domain enzyme. Glucose binding to one site, and ATP to the other
Which sugars to Glut 2 take?
glucose, fructose and galactose
What is the end product of gluconeogenesis and can be used to make glycogen
glucose 6-phosphate
What is the action of phophohexose isomerase?
regroup 6 member ring to a 5 member ring
convert glucose-6-p to fructose 6-p
What’s the action of phosphofructokinase? When is it active?
initiate the irreversible glycolysis pathway
it is active when there is low [ATP]
What is needed in anaerobic metabolism
NAD+
why do we produce lactic acid in anaerobic metabolism
to regenerate NAD+
Which cells of the body are obligate anaerobes
retina and red cells
T/F fatty acids are glucogenic
False, they are ketogenic
what is lactose made of?
galactose and glucose
what’s the reaction converting galactose to glucose?
epimerisation
Why is fructose bad for you?
it tends to make fatty acid
