Plant Cell Wall

Question 1

major function of cell wall

Answer 1

to provide cell shape and protection. cell differentiation

Question 2

cell wall constitutes [blank] % of the dry weight of a plant

Answer 2

15 - 30%

Question 3

3 components of the plant cell wall

Answer 3

primary, secondary, middle lamella

Question 4

the primary cell wall:

Which plant have a primary cell wall?

Contains a network of [blank]?

The primary wall forms [blank] and is responsible for [blank]

Answer 4

all

cellulose microfibrils, hemicellulose, pectin, proteins

first, cell shape and growth

Question 5

Secondary Cell Wall

Found in specific cells like [blank], which contributes to the [blank] of wood.
The secondary wall is [blank] to the primary wall and composed of additional layers of cellulose and [blank] for rigidity.

Answer 5

xylem, strength of the wood.

internal

lignin for rigidity

Question 6

Middle Lamella

A [blank] layer that glues [blank] cells together, playing a critical role in maintaining [blank] and tissue integrity.

Answer 6

pectin-rich

adjacent cells

cell adhesion

Question 7

Composition of Cellulose Microfibrils

Cellulose microfibrils are composed of long polymers of [blank].
These microfibrils, by weight, are [blank] than steel.

Answer 7

polymers of glucose (β-1,4-glucosyl bonds).

stronger than steel

Question 8

Synthesis of Cellulose Microfibrils

Synthesized by the enzyme complex [BLANK], which is organized into [blank]

Answer 8

cellulose synthase, rosettes in PM

Question 9

Synthesis of Cellulose Microfibrils

Each rosette contains multiple [blank] producing bundles of [blank] that are crucial for [blank]

Answer 9

cellulose synthase subunits like CESA3

cellulose chains

wall strength

Question 10

Role of Hemicellulose

Composed of [blank] which [blank] via [blank].

These cross-links contribute to the [blank] nature of the cell wall.

Answer 10

linear polymer (xyloglucan), cross-link microfibrils, hydrogen bonds

dynamic and adaptable

Question 11

Role of Pectin

Determines the [blank] of the cell wall and is crucial for the middle lamella structure.

Answer 11

porosity

Question 12

Role of proteins

Expansin proteins facilitate cell [blank] by breaking [blank], allowing for cell expansion.

Answer 12

wall loosening, breaking h bonds

Question 13

Role of proteins

[blank] proteins stabilize the cell wall structure.

Answer 13

extensin

Question 14

Mechanisms of Expansion

Cell walls can loosen to permit growth, which is regulated by the [blank] bonds between [blank]

Answer 14

hydrogen, hemicellulose and microfibrils

Question 15

Mechanisms of cell expansion

Cell expansion is driven by [blank] (a kind of pressure) exerted against the loosened cell wall.

Answer 15

positive turgor

Question 16

Protoplast Formation:

Cell walls can be digested [blank] to produce [blank], which are useful for [blank] and studying [blank]

Answer 16

enzymatically, protoplasts

genetic manipulation, wall regeneration

Question 17

Microtubule Guidance in Cell Wall

The movement and polymerization of cellulose synthase complexes are guided by [blank]

Answer 17

cortical microtubules

Question 18

Microtubule guidance in cell wall

Changes in microtubule [blank] directly affect the [blank] of newly synthesized microfibrils.

Answer 18

orientation, alignment and pattern

Question 19

Coordinated Synthesis of microfibrils

Vesicles deliver [blank] to the membrane, where interactions with microtubule-associated proteins [blank] facilitate the correct assembly and alignment of microfibrils.

Answer 19

MAP4

Question 20

Vesicle-Mediated Transport

Specialized vesicles [blank] transport cellulose synthase from the [blank] to the [blank].
The delivery and fusion of these vesicles are tightly regulated to ensure efficient cellulose synthesis.

Answer 20

SmaCCs and MASCs, golgi to PM