Lecture 5

Question 1

Amount of lignin in xylem

Answer 1

20%

Question 2

Lignin acts as the __ in the cell wall

Answer 2

Concrete

Question 3

Lignin configuration

Answer 3

Not predictable

Question 4

What is lignin

Answer 4

Amorphous polymer

Question 5

What is lignin connected to

Answer 5

Hemicellulose

Question 6

What is lignin composed of

Answer 6

Three phenolics that vary by number of methoxy groups

Question 7

Methoxy groups

Answer 7

p-coumaryl alcohol
coniferyl alcohol
sinapyl alcohol

Question 8

Three basic building blocks of ligin

Answer 8

Hydroxyphenyl
Guaiacyl
Syringyl

Question 9

How are the three basic building blocks of lignin formed

Answer 9

Monolignols are polymerized

Question 10

What does lignin originate from

Answer 10

The amino acid phenylalanine

Question 11

Are the enzymes leading to the production of the three alcohol unite from phenylalanine understood

Answer 11

Yes

Question 12

Are the mechanisms for building the lignin polymer understood

Answer 12

No

Question 13

Theories for the mechanisms of building the lignin polymer

Answer 13

Helper proteins, oxidative enzymes, and random formation

Question 14

What does lignin composition vary by

Answer 14

Species and cell type

Question 15

In softwoods, lignin is almost entirely

Answer 15

G lignin (with some H)

Question 16

In hardwoods, lignin is essentially a mixture of

Answer 16

S and G lignin (with some H)

Question 17

How is the composition of lignin determined

Answer 17

Thioacidolysis (using ethanethiol as a reagent) combined with gas chromatography

Question 18

Phenotype of trees with diminished CAD activity

Answer 18

Reddish color

Question 19

Lignin is a great starting material for ___-based products

Answer 19

Carbon

Question 20

Products of lignin

Answer 20

Carbon fiber
Resins
Adhesives
Binders
Phenolic chemicals

Question 21

____ (flowering agent) is easily released for lignin

Answer 21

Vanillin

Question 22

Lignin product company

Answer 22

ENSYN