Glycolysis Flashcards
(27 cards)
how do we know if FAD is reduced or not
can measure the absorption as it changes when reduced/oxidised
can determine the structure - when reduced flavin ring has a butterfly structure
what are monosaccharides and examples
hexoses and pentoses
saccharide monomers of sugars
glucose, galactose, ribose
examples of disaccharides and what they are made of
sucrose (glucose + fructose)
lactose (galactose + glucose)
maltose (glucose + glucose)
why is glucose the most important sugar in humans
it is the sole energy source for the brain/blood
what are polysaccharides
polymers of mono- or disaccharides
what polysaccharide is glucose stored as in animals
why
glycogen
its structure doesn’t take up too much space
what is the structure of glycogen
1-4 and 1-6 bonds
branched structure every ~10 subunits
what is the function of glycolysis
generation of ATP from free energy from glucose
partially break down glucose and provide a starting point for the TCA cycle
what is the function of the TCA cycle
the completion of oxidation of glucose
where in the body does glycolysis occur
muscle
brain
heart
adipose tissue
intestine
liver
where in the cell does glycolysis occur
cytosol
how does glucose get to the tissues that perform glycolysis
via the blood and enters cells via GLUT transporters
what is the chemical formula of glycolysis
C6H12o^ + 2ADP + 2Pi + 2NAD+ -> 2 pyruvate + 2 ATP + 2H2O + 2NADH + H+
what type of phosphorylation is the generation of ATP
substrate level phosphorylation
what type of phosphorylation is the consumption of ATP
oxidative level phosphorylation
explain the investment stage of glycolysis
two ATP consumed
glucose is phosphorylated and cleaved
explain stage two of glycolysis
four ATP produced
two molecule of G3P (glyceraldehyde-3-phosphate) are converted into pyruvate
what are the three part of glycolysis
priming
cleavage
oxido-reduction-phosphorylation
does hexokinase or glucokinase have a higher affinity for glucose
what does this high affinity allow
hexokinase
allows utilisation of glucose even when blood glucose is low
where is the first regulation of glycolysis
substrates and products of step 1 act as allosteric regulators
products create a negative feedback loop when their concentration is high (fructose-6-phosphate, ATP)
what is oxidative phosphorylation
regeneration of ATP by coupling its formation to more highly exergonic metabolic process
why can stage 2 be seen as exergonic and endergonic
energy is used to create ATP but also half of the energy of the reaction is lost as heat
what are the three irreversible steps in glycolysis
what enzymes catalyse them
1) glucose -> glucose 6-phosphate, hexokinase
3) fructose 6-phosphate ->
which enzymes of glycolysis does ATP inhibit the activity of
phosphofructokinase and pyruvate kinase
