1. Biomolecules and Biofuels Laura Penman

2. Q. Why Biofuel?

3. What are the sources of biofuel? A Biofuel can be any renewable organic molecule that releases usable energy – Renewable: able to be generated repeatedly – Organic: based on carbon skeletons » From living things or once-living things

4. Four different kinds of organic molecules Carbohydrates – Sugar-based (starches, glycogen, cellulose) Proteins – Amino acid based (actin, keratin, collagen) Lipids – Don’t mix well with water (oils and fats) Nucleic Acids – Nucleotide-based (DNA and RNA)

5. Molecules can be put together Dehydration Synthesis!! OH HOHOO O-H H

6. Molecules can also be broken down O OH HOHO O-H H Hydrolysis

7. Note that water (H 2 0) is involved in both! Dehydration synthesis removes H+ and OH- from two different molecules to synthesize (put together) a polymer Hydrolysis uses a water molecule to split (lyse) a big molecule into two smaller ones

8. Connections to biofuel Hydrolysis is often used to release energy from molecules (Dehydration synthesis is used to build complex polymers)

9. Your body uses organic molecules as fuel Calorie : a measure of energy in a molecule 9 calories /gram lipids 4 calories/gram carbohydrate 4 calories / gram protein

10. So do your automobile engines Biodiesel Oil-based plant or animal sources Ethanol Sugar-based Plant sources

11. Q. What is “ethanol”? Aka. ethyl alcohol Clear, colorless liquid Flammable

12. Q. How is alcohol/ethanol made? By fermenting sugars – Fructose – Maltose – Sucrose What do you suppose “-ose” means?

13. Q. How does the sugar get fermented? By yeast, when oxygen isn’t present

14. BASIC ethanol production Carbohydrate source  sugars  ethanol EASY Been there, done that The challenge

15. Does ethanol production from carbohydrates involve Hydrolysis or Dehydration synthesis?

16. BASIC ethanol production Carbohydrate source  sugars  ethanol EASY Been there, done that The challenge

17. “Major players” in biofuel ethanol (NOT grape juice) Corn sugars/starches PRO: fermentation technique is established – Starch  sugar  ethanol CON: $ to plant each year, irrigate, fertilize Sugar cane PRO: fermentation technique is established – Sugar  ethanol CON: doesn’t grow in the USA Switchgrass and willow PRO: native perennial to most of USA, easy to grow CON: processing is not worked out yet – Cellulose-->sugar?????

18. Which leads us to today’s lab… Switchgrass (Panicum virgatum) --a low-cost and low-labor source of cellulose in this region – Perennial (harvest biomass yearly) – Minimal nutrient requirements – Able to handle a range of water conditions

19. Plant cell Cell wall Cellulose fibers Fiber Cellulose + Hemicellulose + Lignin Microfibers Cellulose + Hemicellulose Cellulose Molecule Switchgrass Cellulose is in the cell walls of each plant cell

20. Switchgrass provides a great source of biomass (potential fuel) BIG organic molecules (like cellulose) are called polymers – Made from small subunit molecules called monomers

21. Cellulose structure glucose Cellulose is a chain molecule made of small units of glucose (sugar): Choose one: Cellulose is a monomer or polymer? Choose one: Glucose is a monomer or polymer?

22. A special chemical was found that breaks down cellulose polymers into glucose! If we maximize this breakdown process, we will have plenty of glucose to ferment! Your challenges are : – To determine what kind of molecule “accellerase” is (Part 1) – To determine the effect of pH on this process! (Part 2) AccelLerase

23. Accellerase is an organic molecule You will learn which type in lab (Part II) – Indicators change colors in the presence of certain molecules Benedicts turns blue-- if it is a sugar Iodine turns black-- if it is a starch Biurets turns purple-- if it is a protein Sudan IV turns red-- if it is a lipid

24. What kind of molecule is Accellerase? Sugar Carbohydrate Starch Carbohydrate ProteinLipid Test name Color of negative control Material in positive control Color or positive control Color of Accellerase after test

25. Maximizing “Accellerase” What can we control in order to get the most “bang for our buck”? – Prepare experiment to study two factors 1) pH 2) size of switchgrass material

26. Size of switchgrass material Your group will be assigned one of the following types of switchgrass – Cut switchgrass leaves – Pelletized switchgrass leaves – Powdered switchgrass leaves

27. Every group will examine the effect of pH on “accellerase” activity

28. Treatment series 1 (Tubes 1, 2, 3, and 4) – 4 tubes containing 15 ml of the following solutions pH 3, pH 5, pH 7, pH 9 – Add 5 g switchgrass to each tube – Add 0.5 ml Accellerase Treatment series 2 (Tubes 5, 6, 7, and 8) – 4 tubes containing 15 ml of the following solutions pH 3, pH 5, pH 7, pH 9 – Add 5 g switchgrass to each tube – DO NOT add Accellerase

29. pH ___3____pH ___5____pH ___7____pH ____9___ Switchgrass + Accellerase Switchgrass without Accellerase

30. ASSIGNMENT for next lab period: Complete questions in handout for part I Also form hypotheses regarding pH and pretreatment of switchgrass

31. Did accellerase increase glucose production? Were the effects of accellerase similar for all pH levels? Which pH helped accellerase work the best? Prepare a graph showing your results. Based on your graph, which pH range would you want to test as you “iron out” the technique?

32. “Accellerase” & Cellulose breakdown Some enzymes are used by organisms to break down (digest) polymers (Other enzymes are used by organisms to build polymers) Enzymes end with “-ase” Cellulase enzymes can break down cellulose into its sugar molecules.

33. Conversion of cellulose Cellulase (enzyme) Cellulose molecule 1- The enzyme recognizes the cellulose molecule 2- The enzyme cuts the atomic bond 3- One molecule of glucose is released 4- The enzyme advances to the other unit The enzyme processes along the cellulose molecule The cellulose is converted into fermentable sugars

34. Enzymes are proteins The function of enzymes relies on their shape. Denaturation: permanent loss of enzyme function by permanently altering its shape Temperature – too high pH— too high or too low

35. Biomolecule Review Remember that – Ethanol is “sugar-based” – Biodiesel is “lipid-based”

36. Source for ethanol or biofuel?