CH. 15 Flashcards
Define Glycolysis?
the breakdown of glucose to pyruvate while using the free energy released to synthesize ATP from ADP and Pi.
Where are the enzymes of glycolysis located.
in the cytosol
How many reactions occur in glycolysis?
10
Glycolysis is divided into two stages, what are they?
1. Energy Input [Energy investment]
2. Energy Output [Energy recovery]
How many reactions occur in the first stage of glycolysis
Reactions 1-5
What is the overall outcome of the first stage of glycolysis?
one molecule of glucose is converted to two glyceraldehyde-3-phosphate (G3P) molecules.
how much energy is consumed in the Energy Imput (stage 1) of glycolysis?
2 ATP
How many reactions occur in the second stage of glycolysis?
reactions 6-10
What is the overall outcome of the second stage of glycolysis?
two glyceraldehyde-3-phosphate molecules are converted to two pyruvate molecules.
how much energy is generated in the energy output (stage 2) of glycolysis?
4 ATP and 2 NADH
What is the overall outcome of glycolysis?
one glucose molecule is converted to two pyruvate molecules, creating a ‘net’ profit of 2 ATP and 2 NADH
What is the overall reaction of glycolysis?
Glucose + 2 NAD+ + 2 ADP + 2 Pi ⇒ 2 pyruvate + 2 NADH + 2 ATP + 2 H2O + 4 H+
What is the primary oxidizing agent for the glycolysis pathway?
NAD+
What happens in Reaction 1 of Glycolysis
the transfer of a phosphoryl group from ATP to glucose to form glucose-6-phosphate (G6P)
Properties of Reaction 1
- Enzyme
- Substrate
- True Co-Substrate
- hexokinase
- Mg2+
- (Mg(ATP))2-
What is a kinase
an enzyme that transfers phosphoryl groups between ATP and a metabolite
Explain Reaction 2 of Glycolysis
Glucose-6-phosphate is converted to fructose-6-phosphate (F6P)
Properties of Reaction 2
- Enzyme
- Catalytic Sequence
- Phosphoglucoisomerase
- Aldopyranose ⇔ Aldose ⇔ Ketose ⇔ Ketofructose
Explain Reaction 3 of Glycolysis
the transfer of a phosphoryl group from ATP to fructose-6-phosphate to form fructose-1,6-bisphosphate (G6P)
Properties of Reaction 3
- Enzyme
- Enzymes special physical properties
- ATP rules
- Phosphofructokinase-1 (PFK-1)
- Has two binding sites
- ATP has a co-substrate (active site) OR ATP is an inhibitor (allosteric site)
At the allosteric site of phosphofructokinase-1, which modulator(s) inhibit the enzyme?
ATP and Citrate
At the allosteric site of phosphofructokinase-1, which modulator(s) activate the enzyme?
ADP & AMP, ß-(D)-Frc-2,6-biphosphate
Explain Reaction 4 of Glycolysis
the cleavage of Fructo-1,6-bisphosphate to form two trioses glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP)
What are the two types of aldolases
Class 1 and Class 2
