Anaerobic Metabolism - The Glycolysis Pathway

Where does glycolysis take place?

Glycolysis takes place in all tissues.

Glycolysis occurs in 4 stages. Fill in the blanks to describe them below. 1. Activation of [blank_start]glucose[blank_end] using [blank_start]ATP[blank_end] 2. [blank_start]Lysis[blank_end] of 6C sugar into two 3C compounds 3. [blank_start]Oxidation[blank_end] 4. Synthesis of [blank_start]ATP[blank_end]

Fill in the blanks on this image to show how D-glucose and L-glucose form different cyclical isomers.

Which of the following is a correct summary of the reactions that take place in the activation stage of glycolysis?

The phosphorylations that occur in the activation stage of glycolysis both require ATP hydrolysis.

Why do we isomerise glucose 6-phosphate to fructose-6 phosphate in the activation stage of glycolysis?

Which reaction of the activation stage of glycolysis is reversible?

Why do we phosphorylate the substrate for a second time in the activation stage of glycolysis?

Fill in the blanks below to describe the activation stage of glycolysis. 1. First, [blank_start]glucose[blank_end] is phosphorylated to [blank_start]glucose-6-phosphate[blank_end]. This is catalysed by either h[blank_start]exokinase[blank_end] or g[blank_start]lucokinase[blank_end] and requires [blank_start]ATP[blank_end] hydrolysis. 2. [blank_start]Glucose-6-phosphate[blank_end] is isomerised in a [blank_start]reversible[blank_end] reaction catalysed by [blank_start]phosphoglucose isomerase[blank_end]. This forms [blank_start]fructose-6-phosphate[blank_end]. 3. [blank_start]Fructose-6-phosphate[blank_end] is phosphorylated to [blank_start]fructose 1,6-biphosphate[blank_end] by [blank_start]phosphofructokinase[blank_end]. This also requires [blank_start]ATP[blank_end] hydrolysis.

Which glucose kinase has the higher Km and thus lower affinity towards glucose?

Hexokinase occurs in all tissues whereas glucokinase only occurs in the liver and pancreatic B cells.

During the lysis stage of glycolysis, fructose 1,6-biphosphate is cleaved to give two 3 carbon molecules.

Which enzyme catalyses the lysis of fructose 1,6-bisphosphate into glyceraldehyde 3-phosphate and dihydroxyacetone phosphate?

Why is dihydroxyacetone phosphate, one of the products of fructose 1,6-bisphosphate lysis, isomerised into glyceraldehyde 3-phosphate by triose phosphate isomerase?

Fill in the blanks below to summarise the lysis stage of glycolysis. [blank_start]Aldolase A[blank_end] enzyme splits [blank_start]fructose 1,6-bisphosphate[blank_end] into g[blank_start]lyceraldehyde 3-phosphate[blank_end] and d[blank_start]ihydroxyacetone phosphate[blank_end]. [blank_start]Triose phosphate[blank_end] isomerase enzyme catalyses the isomerisation of [blank_start]dihydroxyacetone phosphate[blank_end] to [blank_start]glyceraldehyde 3-phosphate[blank_end]. This can then be oxidised in the next stage.

Which coenzyme is used to oxidise glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate in the oxidation stage of glycolysis?

A source of inorganic phosphate is required to form 1,3-bisphosphoglycerate from glyceraldehyde 3-phosphate in the oxidation stage of glycolysis.

Fill in the blanks below to describe the oxidation stage of glycolysis. [blank_start]Glyceraldehyde 3-phosphate[blank_end] is oxidised, forming [blank_start]NADH[blank_end] + H+ from [blank_start]NAD+[blank_end]. [blank_start]Inorganic phosphate[blank_end] is also added. This forms [blank_start]1,3-bisphosphoglycerate[blank_end] in a reaction catalysed by [blank_start]glyceraldehyde 3-phosphate dehydrogenase[blank_end].

Fill in the blanks below to describe the correct sequence of events taking place during the ATP synthesis stage of glycolysis. 1. [blank_start]Dephosphorylation[blank_end] 2. [blank_start]Isomerisation[blank_end] 3. [blank_start]Dehydration[blank_end] 4. [blank_start]Dephosphorylation[blank_end]

During which reactions of the ATP synthesis stage is ATP synthesised? Check all that apply.

Fill in the blanks below to describe the ATP synthesis stage of glycolysis. 1. [blank_start]1,3-bisphosphoglycerate[blank_end] is dephosphorylated to [blank_start]3-phosphoglycerate[blank_end]. This involves the synthesis of [blank_start]ATP[blank_end]. This is catalysed by [blank_start]phosphoglycerate kinase[blank_end]. 2. [blank_start]3-phosphoglycerate kinase[blank_end] is isomerised to [blank_start]2-phosphoglycerate[blank_end] in a reaction catalysed by [blank_start]phosphoglycerate mutase[blank_end]. 3. [blank_start]2-phosphoglycerate[blank_end] is dehydrated to [blank_start]phosphoenol pyruvate[blank_end]. This involves the loss of [blank_start]water[blank_end] and is catalysed by [blank_start]enolase[blank_end]. 4. [blank_start]Phosphoenolpyruvate[blank_end] is dephosphorylated to [blank_start]pyruvate[blank_end]. This involves the synthesis of [blank_start]ATP[blank_end] and is catalysed by [blank_start]pyruvate kinase[blank_end].

Fill in the blanks to describe the ATP yield from glycolysis. In the activation stage of glycolysis, we use [blank_start]2[blank_end] ATP molecules to [blank_start]phosphorylate[blank_end] glucose twice. Later in the [blank_start]ATP synthesis[blank_end] stage of glycolysis, we synthesise [blank_start]2[blank_end] ATP molecules from [blank_start]dephosphorylation[blank_end] reactions. However, because each glucose molecule is split into 2, all the reactions following the [blank_start]lysis[blank_end] stage occur twice. Thus, we yield [blank_start]4[blank_end] ATP from each glucose molecule. However, because of the loss of the [blank_start]2[blank_end] ATP molecules in activation, we have a yet yield of [blank_start]2[blank_end] ATP molecules per glucose molecule.

Which coenzyme is formed in the reduction of pyruvate to lactate?

Which enzyme catalyses the reduction of pyruvate to lactate?

Why is it necessary to convert pyruvate to lactate in anaerobic conditions?

Why is glycolysis important in erythrocytes?

Which substances inhibit phosphofructokinase, preventing the second phosphorylation of fructose 6-phosphate to fructose 1,6-bisphosphate thus halting glycolysis?

WHY does AMP activate phosphofructokinase, thus driving the second phosphorylation of fructose 6-phosphate to fructose 1,6-bisphosphate and increasing the rate of glycolysis?