CONCLUSION_GLYCOLYSIS

Other simple sugars can enter glycolysis if they are converted into what?

Appropriate intermediates

Which simple sugar besides glucose can enter the glycolytic pathway?

Fructose

Which monosaccharide from milk metabolism can enter glycolysis?

Galactose

Which sugar derived from polysaccharides can feed into glycolysis?

Mannose

Entry of alternative sugars into glycolysis depends on what factor?

Specific enzymes converting them to intermediates

Which enzyme catalyzes the conversion of glucose to glucose 6-phosphate?

Hexokinase

What molecule inhibits hexokinase activity through feedback inhibition?

Glucose 6-phosphate

Which step of glycolysis is catalyzed by phosphofructokinase?

Conversion of fructose 6-phosphate to fructose 1,6-bisphosphate

Which substances inhibit phosphofructokinase activity?

ATP and citrate

Which step is catalyzed by pyruvate kinase?

Conversion of phosphoenolpyruvate to pyruvate

What compound inhibits pyruvate kinase activity?

ATP

Which enzymes in glycolysis are allosterically regulated?

Pyruvate kinase and phosphofructokinase

What is the general effect of allosteric regulation in glycolysis?

Controls glucose breakdown rate

What molecule does glycolysis continuously require for oxidation reactions?

NAD+

What must happen if oxygen is unavailable to regenerate NAD+?

NADH must be reoxidized by another pathway

In aerobic conditions, pyruvate is oxidized to what compound?

Acetyl-CoA

Where does oxidation of pyruvate to acetyl-CoA occur?

Mitochondrial matrix

Which enzyme complex catalyzes pyruvate oxidation?

Pyruvate dehydrogenase complex

What kind of conditions are required for oxidation of pyruvate to acetyl-CoA?

Aerobic (oxygen-rich)

Which cycle does acetyl-CoA enter after formation?

Citric acid cycle

Under what conditions does lactate fermentation occur?

Anaerobic (oxygen-deficient)

In which tissue does lactate fermentation mainly take place?

Muscle

Which enzyme catalyzes the conversion of pyruvate to lactate?

Lactate dehydrogenase

What cofactor is regenerated in lactate fermentation?

NAD+

What happens to lactate when oxygen becomes available again?

Converted back to pyruvate

What ions increase in concentration during lactate accumulation?

H+ ions

Under what conditions does ethanol fermentation occur?

Anaerobic conditions in microorganisms

Which enzyme catalyzes the first step of ethanol fermentation?

Pyruvate decarboxylase

Which enzyme catalyzes the second step of ethanol fermentation?

Alcohol dehydrogenase

What are the end products of ethanol fermentation?

Ethanol, CO₂, and NAD+

Which organisms commonly perform ethanol fermentation?

Yeast and bacteria

What are the two main types of fermentation pathways?

Lactate and ethanol fermentation

What determines the fate of pyruvate after glycolysis?

Presence or absence of oxygen

In glycolysis, how many ATP molecules are consumed during the energy investment phase?

Two

How many ATP molecules are produced during the energy payoff phase?

Four

How many NADH molecules are generated in the energy payoff phase?

Two

What is the overall end product of glycolysis?

Pyruvate

Under aerobic conditions, pyruvate is converted to what?

Acetyl-CoA

Under anaerobic conditions in yeast, pyruvate is converted to what?

Ethanol and carbon dioxide

Under anaerobic conditions in muscles, pyruvate is converted to what?

Lactate

Which three enzymes are key regulatory points in glycolysis?

Hexokinase, phosphofructokinase, pyruvate kinase

What is the metabolic pathway that synthesizes glucose from pyruvate?

Gluconeogenesis

Is gluconeogenesis the exact reverse of glycolysis?

No

Most enzymes of glycolysis are also used in which process?

Gluconeogenesis

Why can’t gluconeogenesis simply reverse all glycolytic reactions?

Irreversible high-energy steps exist

Which product of glycolysis requires bypass reactions during gluconeogenesis?

Pyruvate

Which enzyme catalyzes the first bypass reaction in gluconeogenesis?

Pyruvate carboxylase

Which enzyme catalyzes the second bypass reaction in gluconeogenesis?

Phosphoenolpyruvate carboxykinase

What class of enzymes removes phosphate groups from bisphosphate intermediates?

Phosphatases

What cellular condition triggers glycolysis to increase?

Low ATP levels

What cellular condition inhibits glycolysis?

High ATP levels

What cellular process ensures continuous ATP production under anaerobic conditions?

Fermentation

In what organ does gluconeogenesis primarily occur?

Liver

What is the role of NADH in glycolysis?

Electron carrier for oxidation reactions

What is the role of pyruvate dehydrogenase in metabolism?

Converts pyruvate to acetyl-CoA

What is regenerated in both lactate and ethanol fermentation?

NAD+

What is the purpose of fermentation processes overall?

Maintain NAD+ supply for glycolysi