Week 7- Introduction to Chemical Energy, Glycolysis

Question 1

Metabolism

Answer 1

• both biosynthesis of complex organic molecules and their breakdown
• Catabolism (exergonic): oxidation reaction and generate energy
• Anabolism (endergonic):
  reduction reaction and require energy

Question 2

Breakdown and Metabolism

Answer 2

• Digested food becomes source of metabolic energy (monomers)
  1. starch to glucose (saliva)
  2. protein to a.a (gastric protease)
  3. Lipid to fatty acid (lipase in pancreas)
• Monomers absorbed by cell through membrane transports
• Metabolism of monomers generate energy for growth and other activities

Question 3

Metabolism and Cofactors

Answer 3

• Catabolism: oxidation and loss of electron
• Anabolism: reduction
• Metabolic cofactors: Q, NAD+ and NADP+
• NAD+ involved in catabolic reactions
• NADP+ involved in anabolic reactions
• Ubiquinone (Q) involved in membrane electron transfer

Question 4

Cofactors and electron transfer

Answer 4

• oxidation-reduction reactions involve transfer of electron
• electron lost during oxidation is accepted by reduction reaction

Question 5

Metabolic pathways

Answer 5

• ATP and NADH
• Glycolysis
• Citric Acid Cycle
• Electron transport
• ATP (chemical energy)

Question 6

Free energy and ATP

Answer 6

• ATP represents chemical energy
• Cleavage of phosphoanhydride bonds releases large amount of energy
• example of energy usage: phosphorylation reaction of glucose

Question 7

Overview of glycolysis

Answer 7

• Glycolysis and fermentation: series of enzymatic reactions to convert 6-carbon glucose to two 3-carbon pyruvate and generate 2 ATPS
• Glucose: breakdown product from carbohydrates and glucose enters cells by membrane transport
• Stages in glycolysis:
  1. energy investment
  2. energy recovery