Cellulose, Hemicellulose, Lignin Flashcards
1
Q
Which of the following elements cannot be found in cellulose?
A
Nitrogen
2
Q
The molar mass of cellulose in g/mol is:
A
162.14
3
Q
The density of cellulose in g/cm3 is:
A
1.5
4
Q
What is the melting point of cellulose in degrees Celsius?
A
260
5
Q
What is the color of cellulose?
A
White
6
Q
First discovery of cellulose was in the year ___– [French chemist by name ___ ___ ]
A
1838 , Anselme Payen
7
Q
It is a complex carbohydrate consisting of oxygen, carbon, and hydrogen
A
Cellulose
8
Q
It is an organic compound and is water-soluble and biodegradable. It is chiral, tasteless and has no odor
A
Cellulose
9
Q
the first thermoplastic
A
celluloid
10
Q
Majority of the properties of cellulose depend upon the ___ ____ or chain length and the number of glucose
molecules constituting the polymer molecule.
A
degree of polymerization
11
Q
small molecules which may be joined together in a repeating fashion to form more complex molecules called polymers
A
Monomer
12
Q
may be a natural or synthetic macromolecule comprised of repeating units of a smaller molecule (monomers)
A
Polymer
13
Q
Polysaccharide of glucose units in unbranched chains with ß-1,4,- glycosidic bonds
A
Cellulose
14
Q
3 Kinds of Sugar
A
Monosaccharide
Disaccharide
Polysaccharides
15
Q
- contain just one molecule
(ex. Dextrose, Glucose, Fructose and Galactose)
A
Monosaccharide
16
Q
complex structure of sugars
(ex. Sucrose and maltose)
A
Disaccharide
17
Q
major classes of biomolecules; long chains of carbohydrate molecules, composed of several smaller monosaccharides
(ex. starches and cellulose)
A
Polysaccharides
18
Q
both the glucose, alpha glucose and
beta glucose have the same structure, just the ___ ___ __ __ ___ is different.
A
orientation of the hydroxyl group
19
Q
cellulose microfibril are __-__ mm wide
A
5 to 12
20
Q
microfibrils contain __-__ individual chains
A
20 to 40
21
Q
The process of cellulose degradation
A
Cellulolysis
22
Q
The main monomer that composes cellulose
A
Glucose
23
Q
INTERMIDIATE UNITS THAT ARE MADE FROM CELLULOSE
A
Cellobiose
Cellotriose
Cellotetraose
24
Q
when two glucose molecules are connected (ex. maltose)
A
Cellobiose
25
When three glucose units are connected (ex. β -D pyranose form)
Cellotriose
26
four glucose units connected together
Cellotetraose
27
breaking down the crystallinity in the
cellulose to an amorphous strand
Endocellulose
27
hydrolysis of the chain ends to break the
polymer into smaller sugars; products are typically cellobiose and cellotetraose
Exocellulases
28
the disaccharides and tetrasaccharides (cellobiose and cellotetraose) are hydrolyzed to form glucose
β-glucosidases
29
In this process, enzymes are used to hydrolyze the cellulose (C6 Sugars) and hemicellulose (C5 Sugar)
Enzymatic Hydrolysis
30
Produces cellulase enzymes- needed to convert cellulose and hemicellulose to sugars
Trichoderma reesei
31
Enzyme producers
Iogen
Genecor
Verenium
32
In this process, ethanol and required enzymes are produced from the same microorganism
Direct Microbial Conversion
33
The three primary constituents of biomass
Cellulose
Hemicellulose
Lignin
34
means the breakdown of cellulose when it is exposed to high temperature or heat
Thermolysis
35
Thermolysis of cellulose occurs at 350 degrees, when decomposes into vapors of carbon dioxide and other aerosols. This temperature is called ______ ____ or ____ ____.
thermolytic temperature or pyrolytic temperature.
36
process of decomposition of various compounds or materials with thermal decomposition at temperatures around 400–800°C in an oxygen-free atmosphere or contain very small amount of oxygen
Pyrolytic/Pyrolysis
37
Cellulose - Derivative
Cellulose acetate
Cellulose Acetate Butyrate
Carboxymethyl cellulose
ethyl cellulose
38
Synthetic compound derived from the acetylation of the plant substance cellulose
Acetate Compound
39
commonly prepared by treating cellulose with acetic acid and then with acetic anhydride in the presence of a catalyst such as sulfuric acid.
Acetate Compound
40
can be synthesized by using an acid anhydride or an acid chloride as an acylating agent
Acetate Compound Propionate
41
a cellulose ester wherein some of three hydroxyl groups of a cellulose unit (glucose combined with β1-4 glycoside bond) are substituted with acetyl and propionyl
Acetate Compound Propionate
42
a mixed ester thermoplastic derivative of cellulose acetate that contains both acetate and butyrate functional groups.
Acetate Compound Butyrate
43
it was designed for use where low application viscosities at relatively high solids levels is needed. It is soluble in a wide range of solvents and compatible with many other resins
Acetate Compound Butyrate
44
also known as cellulose gum
Carboxymethyl cellulose
45
a cellulose derivative with carboxymethyl groups (-CH2-COOH) bound to some of the hydroxyl groups of the glucopyranose monomers
Carboxymethyl cellulose
46
a derivative of cellulose in which some of the hydroxyl groups on the repeating glucose units are converted into ethyl ether groups
Ethyl Cellulose
47
one of a number of heteropolymers alongside cellulose
Hemicellulose
47
defined as cell wall polysaccharides that have the capacity to bind strongly to cellulose micro fibrils by hydrogen bonds
Hemicellulose
48
a monosaccharide with five
carbon atoms.
Pentose
49
any of the class of simple sugars whose molecules contain six carbon atoms, such
as glucose and fructose.
Hexose
50
grasses (wheat, corn, rice) contain up to __ of the major hemicellulose found in grasses
40%
51
wood fibers are composed of __-__ of hemicellulose by dry weight
25%– 35%
52
has been found in every land plant species that has been analyzed, including mosses EXCEPT in Charophytes
Xyloglucan (XyG)
53
the most abundant hemicellulose in primary walls of spermatophytes except for grasses
Xyloglucan (XyG)
54
a polysaccharide consisting mainly of xylose residues that may constitute more than 30% of the dry weight in plants
Xylans
55
β-(1→4)-linked polysaccharides containing mannose are widely distributed and FOUND AS main hemicellulose in Charophytes
Glucomannans
56
it is present in softwood plants and in hemicellulose in hardwood plants (including the wood of conifers and dicotyledons), where they serve as __ ___ and in some cases ___ ____
energy reserves, playstructural roles
57
a heterogeneous group of polysaccharides)
cross-link glycans interlocking the cellulose fibers and form a mesh like structure to deposit other polysaccharides.
Hemicelluloses
58
extraction of hemicellulose from lignocellulosic biomass include:
a.Hydrothermal extraction;
b. Steam explosion;
c.Acidic; and
d.Alkaline pretreatments, solvent extraction, and ultrasonic-assisted and microwave assisted processes
58
Pretreatment in hemicellulose extraction
Chemical pretreatment
Physical pretreatment
Combined pretreatment
59
Physical pretreatment
Hydrothermal extraction
Steam explosion
60
Chemical pretreatment
Alkaline extraction
Acid extraction
Solvent pretreatment
61
Combined pretreatment
Physical-chemical pretreatment
Combination of chemical and hydrothermal process
others
62
an environmentally friendly pretreatment process, compared with chemical pretreatment also called autohydrolysis or hot water pretreatment
Hydrothermal Extraction
63
can be considered to be a green technology, because of its ability to prevent corrosion problems and not need chemical recycling
Hydrothermal Extraction
64
___ ___ and _____ are used to pretreat lignocellulosic biomass during steam explosion, in which water vapor penetrates into the cell wall.
High temperature and pressure
65
a common process for separating and extracting hemicellulose from lignocellulosic biomass
Alkaline extraction
66
Inorganic alkali solutions are usually used in alkaline procedures, and ____ solution is the most common.
NaOH
67
In the presence of acid, the hydrogen bonds
between hemicellulose and cellulose break and the hydrolysis of hemicellulose occurs. As a result, the main components of lignocellulosic biomass could be separated.
Acid Extraction
67
the dissolved part of wood when treated with nitric acid
Lignin
67
a natural aromatic (phenolic), a heterogeneous biomacromolecule that exists as the second most abundant polymer, next to cellulose
Lignin
68
it is one of the most abundant biopolymer in nature and a large contributor to the residues of the terrestrial biomass, after polysaccharides
Lignin
69
plant polymers made from phenylpropanoid building units
Lignin
70
contain most of the wood methoxyl content
Lignin
71
resistant to acid hydrolysis, readily oxidized, soluble in hot alkaline and bisulfite, and readily condensed with phenols or thiols
Lignin
72
73
fills out the cell walls, which consist predominantly of linear polysaccharidic membranes, providing structural rigidity
Lignin
73
a protective tissue that covers the entire surface of the plant
Epidermal
74
The outermost cell layer of the cortex of
plants. It forms a prominent layer immediately under the epidermis in many but not all plants.
Hypodermal
75
primary building units of lignin
cinnamyl alcohols
coniferyl alcohol
sinapyl alcohol
p-coumaryl alcohol,
76
Gymnosperms are composed almost
exclusively of ___ ___ ___, which are derived from coniferyl alcohol
guaiacyl propane monomers
77
Angiosperm contains approximately equal
proportions of ___ ___units and ___ ___ units, derived from __ ___
guaiacyl propane
syringyl propane
sinapyl alcohol
78
Grasses are composed of about equal proportions of __ ___, ___ ___, and ___ ___ units
guaiacyl propane
syringyl propane
phydroxyphenyl propane
79
ISOLATION OF LIGNIN
Milled Wood Lignin
Enzyme Lignin
Alkali Lignins
Organosolv Lignin
80
first major advance toward separating lignin in a relatively unaltered state. It is based on extensive grinding of plant material in a nonswelling liquid (toluene)
Milled Wood Lignin (Björkman)
80
the best preparation for structural studies of lignins, at least for wood samples.
Milled Wood Lignin
81
produced as a part of natural energy transfer and carbon cycle especially by wood-degrading fungi and bacteria.
Cellulolytic enzymes
82
used to remove most of the polysaccharides from ball-milled wood meal before aqueous dioxane extraction
cellulolytic enzyme
83
Wood lignins require rather drastic hydrolytic treatments (5% sodium hydroxide [NaOH], 130–170 °C) to become soluble in aqueous alkali solutions
Alkali Lignins
84
Lignin dissolved in alkali hydrogen peroxide solution has found no other practical use except for___ ___ in pulping mill
fuel burnt
85
recovered from spent organosolv pulping liquor by precipitation in water after evaporating organic solvents.
Organosolv Lignin
86
Four types of cellulosel
1 Bacterial cellulose
2. Cellulose acetate
3. Ethylcellulose
4. Hydroxypropyl cellulose
