Lecture 9

Question 1

Second generation biofuels

Answer 1

Those that are derived from cellulosic biomass

Question 2

Can ethanol be produced by yeast fermentation

Answer 2

Yes

Question 3

What do the sugars come from when ethanol is produced by yeast fermentation

Answer 3

Cellulose/hemicellulose

Question 4

Accessing sugars from the cell wall is complicated by ___

Answer 4

Lignin

Question 5

Challenges of cellulosic ethanol

Answer 5

Deligninfication
Depolymerization
Fermentation

Question 6

Enzymes that help with breaking down the cellulose polymer into glucose unite for fermentation after lignin removal

Answer 6

Endoglucananse
Exoclucanase
Glucosidase

Question 7

Endoglucanase

Answer 7

Cleaves cellulose chains in the middle of the strands

Question 8

Exoglucanase

Answer 8

Processes cellulose chains from an exposed end

Question 9

Glucosidase

Answer 9

Cleaves cellobiose into two glucose units

Question 10

What secretes the enzymes needed to break down the cellulose polymer for fermentation

Answer 10

Various fungi (Trichoderma reesei)