Name ______Date ______Period _____

STAGE 1: GLYCOLYSIS

Raven Ch.9

Big Idea 2: BIOLOGICAL SYSTEMS UTILIZE FREE ENERGY AND MOLECULAR BUILDING BLOCKS TO GROW, TO REPRODUCE AND TO MAINTAIN HOMEOSTASIS.

Essential Knowledge:

Cell membranes are selectively permeable due to their structure.

Growth and dynamic homeostasis are maintained by the constant movement of molecules across membranes.

Eukaryotic cells maintain internal membranes that partition the cell into specialized regions.

  • All biological systems from cells and organisms to populations, communities and ecosystems are affected by complex biotic and abiotic interactions involving exchange of matter and free energy.
  • Homeostatic mechanisms reflect both common ancestry and divergence due to adaptation in different environments.

Glycolysis

  • Breaking down ______
  • “glyco – lysis” (splitting sugar)
  • ancient pathway which harvests energy
  • where energy transfer ______
  • transfer energy from ______to ______
  • still is starting point for ALL cellular respiration
  • but it’s ______
  • generate only ______for every ______
  • occurs in ______

In thecytosol?Why doesthat makeevolutionarysense? ______

Evolutionary perspective

  • Prokaryotes
  • first cells had no organelles
  • Anaerobic atmosphere
  • life on Earth first evolved without free oxygen (O2) in atmosphere
  • energy had to be captured from organic molecules in absence of O2
  • Prokaryotes that evolved glycolysis are ancestors of all modern life
  • ALL cells still utilize glycolysis

What does it mean that enzymes of glycolysis are “well-conserved”? ______

______

Glycolysis Overview: 10 reactions

Purpose: convert ______(6C) to ______(3C)

Produces: ______& ______

Consumes: ______

Net yield: ______& ______

Glycolysis summary

______

Substrate-level Phosphorylation

  • In the last steps of glycolysis, where did the P come from to make ATP?
  • the sugar substrate (PEP)

Energy accounting of glycolysis

  • Net gain = ______+ ______
  • some energy investment (-2 ATP)
  • small energy return (4 ATP + 2 NADH)
  • 1- 6C sugar  2- 3C sugars

Is that all there is?

  • Not a lot of energy…
  • for 1 billon years+ this is how life on Earth survived
  • no O2 = slow growth, slow reproduction
  • only harvest 3.5% of energy stored in glucose

more carbons to strip off = more energy to harvest

But can’t stop there!

  • Going to run out of ______
  • without regenerating NAD+, energy production would stop!
  • another molecule must accept H from NADH
  • so NAD+ is freed up for another round

How is NADH recycled to NAD+?

  • Another molecule must accept H from NADH

Fermentation (anaerobic)

  • ______

Examples:

______

______

  • ______

Examples: ______

______

Alcohol Fermentation

  • ______
  • at ______, kills yeast
  • can’t reverse the reaction

Lactic Acid Fermentation

  • ______
  • once O2 is available, lactate is converted back to

______by the liver

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