Lecture 3

Question 1

What is produced by photosynthesis

Answer 1

Glucose (fixed carbon)

Question 2

What do plants use glucose for

Answer 2

Structural integrity of plants, energy for basic cell processes

Question 3

What did terrestrial plants evolve from

Answer 3

Primordial algae and scum

Question 4

What helped terrestrial plants evolve

Answer 4

Firm cell wall

Question 5

How did the cell wall help with evolution of terrestrial plants

Answer 5

Strength for upward and downward growth
Water retention
Barrier against bacteria and other creatures

Question 6

How many layers of the modern cell wall

Answer 6

Two

Question 7

Layers of the modern cell wall

Answer 7

Primary and secondary

Question 8

When is the primary wall deposited

Answer 8

Early in the cells life

Question 9

When is the secondary wall deposited

Answer 9

Late in the cells life

Question 10

Is growth from outside to inside or inside to outside

Answer 10

Outside to inside (secondary forms inside the primary wall)

Question 11

What does the thickness of the wall depend on

Answer 11

Species and type of cell

Question 12

Example of cells with thick cell wall (secondary)

Answer 12

Xylem cell in trees (wood)

Question 13

Which wall has subtypes of layers

Answer 13

Secondary

Question 14

Main components to plant cell walls

Answer 14

Cellulose
Hemicellulose
Lignin

Question 15

Parts of the cell wall that act as rebar

Answer 15

Cellulose and hemicellulose

Question 16

Parts of the cell wall that act as concrete

Answer 16

Lignin

Question 17

How does lignin act as concrete

Answer 17

Sticky substance surrounds the structural filaments of cellulose and hemicellulose

Question 18

Most abundant bio polymer and organic compound on earth

Answer 18

Cellulose

Question 19

What percent of a tree is cellulose

Answer 19

40-50%

Question 20

What is cellulose made entirely of

Answer 20

Beta glucose

Question 21

What is starch made entirely of

Answer 21

Alpha glucose

Question 22

How do alpha and beta glucose differ

Answer 22

Orientation of OH group on the first carbon

Question 23

Alpha and beta glucose are —— of each other

Answer 23

Anomers

Question 24

Carbon that gives rise to different anomers

Answer 24

Anomeric carbon

Question 25

What are glucose molecules joined by in cellulose and what bond is formed

Answer 25

#1 carbon of one molecule and the #4 carbon of the other Beta 1,4 glycosidic bond is formed

Question 26

Name of the simplest cellulose unit

Answer 26

Cellobiose

Question 27

Length of cellulose is referred to as

Answer 27

Degree of polymerization

Question 28

What can the degree of polymerization of cellulose be up to

Answer 28

10,000 (10,000 glucose molecules or more)

Question 29

How are stands of cellulose arranged

Answer 29

In parallel

Question 30

Microfibrils make a

Answer 30

Macrofibril

Question 31

Macrofibrils make a

Answer 31

Cellulose fiber

Question 32

Cellulose chain are secreted from the cell by

Answer 32

Cellulose synthase complexes

Question 33

Cellulose synthase complexes are arranged

Answer 33

In rosettes of six subunits

Question 34

How many microfibrils are produced by the subunits at a time

Answer 34

Six

Question 35

Each fibril emerging from the cell wall is composed of how many glucose chains

Answer 35

36

Question 36

What percent of the plant genome is dedicated to construction, architecture, sensing functions, and metabolism of the plant cell wall

Answer 36

10%, 2,500 genes

Question 37

Most genes involved in cell wall polysaccharide synthesis are grouped into gene families for

Answer 37

Substrate generation, glycosyl transfer, targeting and trafficking, cell wall rearrangement, and modification by hydolysases, esterases, and lyases