Molecular Cell Biology Lecture 2, Part B; Chemistry of a cell

Molecular Cell Biology Lecture Series・2 minutes read

Sugars and fats store energy, but ATP powers cell work, mainly produced in mitochondria. ATP's high-energy bond aids in reactions, while NADH drives electron transport, with glycolysis and the citric acid cycle central to cellular metabolism.

Insights

  • ATP is the primary energy source for cellular work, produced mainly in mitochondria through oxidative phosphorylation and storing energy in phosphoanhydride bonds.
  • NADH plays a crucial role in cellular redox reactions, acting as a major electron donor in the electron transport chain, driving ATP synthesis through oxidative phosphorylation, yielding around 30 ATP molecules per glucose molecule.

Get key ideas from YouTube videos. It’s free

Recent questions

  • What is the main energy source for useful work in cells?

    ATP

  • What is the role of NADH in cellular metabolism?

    Major electron donor in the electron transport chain

  • How are molecules like cholesterol built in cells?

    Anabolic processes

  • What is the significance of acetyl coenzyme A in cellular metabolism?

    Vital cellular intermediate

  • How is energy stored in cells for various processes?

    Phosphoanhydride bonds

Related videos

Summary

00:00

Cellular Energy Production and Storage Mechanisms

  • Sugars can be stored in glycogen and fats, but ATP is the main energy source for useful work in cells.
  • The majority of ATP is produced in mitochondria through oxidative phosphorylation, with energy stored in phosphoanhydride bonds.
  • Energy in cells is also stored in GTP, NAD, NADH, and FAD, with the phosphate from ATP aiding in catalysis and forming intermediates.
  • ATP's high-energy phosphoanhydride bond can be transferred to substrates as an intermediate in reactions.
  • NAD and NADP, forming NADH and NADPH, are crucial for redox reactions, with NADH being a major electron donor in the electron transport chain.
  • Anabolic processes involve building molecules like cholesterol, while catabolic processes break down molecules, with a shift from anabolic to catabolic as people age.
  • Acetyl coenzyme A is a vital cellular intermediate, with a high-energy bond between the acetyl group and coenzyme A.
  • ATP-driven catalysis uses energy from the gamma phosphate to facilitate reactions, such as converting bicarbonate to oxaloacetate.
  • Condensation joins molecules and releases water, while hydrolysis breaks molecules and consumes water, crucial in various cellular processes.
  • Glycolysis converts glucose to pyruvate, producing ATP and NADH, with lactate formed in the absence of oxygen and ethanol produced by yeast fermentation.

20:21

Alcohol, Glycolysis, and ATP in Cellular Metabolism

  • Alcohol consumption can lead to the production of acetylaldehyde, a carcinogen, contributing to diseases like cancer.
  • Understanding glycolysis involves focusing on steps six and seven, which produce reduced NADH and ATP.
  • In step six of glycolysis, glyceraldehyde 3-phosphate reacts with glyceraldehyde three phosphate dehydrogenase to produce reduced NADH and ATP.
  • Step seven of glycolysis involves the transfer of a high-energy phosphate to ADP to generate ATP, resulting in three phosphoglycerate.
  • Different phosphoester bonds on proteins have varying energies, with pyrophosphate releasing more energy than the gamma phosphate.
  • Sugars can be stored as glycogen in cells, while fatty acids are stored in fat droplets and can be used in the TCA cycle.
  • Glycolysis and the citric acid cycle are central to cellular metabolism, producing ATP mainly through oxidative phosphorylation.
  • The reduced NADH produced in the citric acid cycle drives ATP synthesis through oxidative phosphorylation, resulting in approximately 30 molecules of ATP per glucose molecule.
Channel avatarChannel avatarChannel avatarChannel avatarChannel avatar

Try it yourself — It’s free.