Recording-2025-03-24T16:48:39.344Z

Exam Format

• Questions with multiple-choice answers (true/false).

• Write letters of correct answers next to the question number (e.g., a b c).

X-Y Coordinates Task

• Labeled X and Y coordinates are part of the exam.

• Draw relationships based on lab knowledge and calculations.

Underwater Weighing Lab

• Scheduled for next week; bring a swimsuit/shorts and a towel.

• Locker room available for changing.

Anaerobic Glycolysis Overview

• Anaerobic glycolysis means ATP production without oxygen, occurs in the sarcoplasm.

• Starts with one molecule of glucose; ATP is produced for energy.

• Glucose enters the cell facilitated by insulin.

Initial Steps in Glycolysis

• Glucose is phosphorylated by hexokinase (HK) using 1 ATP, forming glucose-6-phosphate.

• Rearranged to fructose-6-phosphate (PFK catalyzed), which is further converted to fructose-1,6-bisphosphate.

Reaction Doubles After Aldolase

• After the aldolase step:

  • Each glucose leads to two molecules of glyceraldehyde-3-phosphate (G3P).

  • All subsequent reactions are doubled per molecule.

Oxidation-Reduction in Glycolysis

• Conversion of G3P to 1,3-bisphosphoglycerate catalyzed by glyceraldehyde-3-phosphate dehydrogenase.

• NAD is reduced to NADH in this reaction (derived from niacin, vitamin B3).

• Total ATP production so far:

  • Gross ATP: 0

  • Net ATP: 0

  • Reduced NAD: 2.

Phosphorylation Steps

• 1,3-bisphosphoglycerate to 3-phosphoglycerate; net ATP: no ATP produced yet.

• 3-phosphoglycerate to 2-phosphoglycerate catalyzed by phosphoglycerate mutase.

• Transition to phosphoenolpyruvate (PEP) then to pyruvate via pyruvate kinase (PK) produces 2 ATP (for each of the two G3P); net ATP from glycolysis is 2.

Anaerobic Pathways

• Pyruvate to lactate catalyzed by lactate dehydrogenase (LDH); this reduces NAD+, using energy through lactate production.

• Only 2 usable ATP produced from one glucose molecule, which is less efficient but quick.

Fates of Pyruvate

• Pyruvate can lead to:

  • Lactate (via LDH)

  • Alanine (via alanine transaminase)

• In mitochondria, pyruvate can contribute to:

  • Oxaloacetate (via pyruvate carboxylase).

  • Requires CO2; ATP-costing reaction.

Important Concepts

• Metabolic pathways overview, ATP production calculations, and recognition of hormonal and enzymatic roles in anaerobic and aerobic pathways should be well understood for the exam.