Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Cels191 > Cell Walls > Flashcards

Cell Walls Flashcards

1
Q

What is the cell wall mainly composed of?

A

Cellulose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What structures does cellulose make within the cell wall?

A

Microfibrils

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the two phases of a cell wall

A
  • Crystalline Microfibrillar Phase

- Noncrystalline Matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the noncrystalline matrix composed of?

A
  • hemicellulose

- Pectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Hemicellulose?

A
  • a heterogenous group of polysaccharides with one long chain of one type of sugar and short side chains
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Pectin?

A

branched, negatively charged polysaccharides that bind water and have gel-like properties

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the extensibility of plant cells controlled by?

A

Extensin cross linking

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What does extensin cross linking do?

A

Dehydrates cell wall, reduces extensibility and increases strength

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the steps of primary cell wall synthesis?

A
  • cellulose myofibrils are synthesized at the cell membrane
  • Polysaccharides (pectin + hemicellulose) in the Golgi apparatus are transported in vesicles to the cell wall
  • Cell wall proteins (extensins) are transported from the rough ER
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is constitutive exocytosis?

A

exocytosis that releases extracellular matrix proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the functions of the cell wall? (3)

A
  • influences cell morphology
  • provides structural support
  • prevents excessive water uptake
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does orientation of cellulose microfibrils influence cell morphology?

A
  • randomly oriented leads to equal expansion in all directions (spherical cell)
  • right angles to ultimate long axis of the cell leads to cell expansion longitudinally along that axis ( rectangle)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a protoplast

A

Name for entire plant cell excluding cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

when is the plant cell rigid?

A

when the protoplast pushes against the cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When are plant leaves wilted?

A

when the protoplast is not pushing on the cell wall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a central vacuole?

A

An organelle surrounded by a highly selective single membrane

17
Q

How does the central vacuole aid in regulation of cell shape?

A
  • There is high concentrations of solutes in the vacuole
  • result is uptake of water by osmosis
  • cell wall limits uptake and prevents cell bursting
  • pressure from vacuole means protoplast pushes on cell wall
18
Q

What happens to an animal cell when put into hypotonic conditions?

A

It bursts - becomes lysed

19
Q

What happens to an animal cell when it is put into hypertonic conditions?

A

It becomes shriveled

20
Q

What happens to a plant cell when put in hypotonic conditions

A

It becomes turgid ( normal / good)

21
Q

What happens to a plant cell in isotonic conditions

A

It becomes flaccid

22
Q

What happens to plant cells under hypertonic conditions

A

Becomes plasmolyzed

23
Q

What is the secondary cell wall

A

Thicker stronger cell wall that is produced once cell growth has stopped and provides more structural support than the primary cell walls

24
Q

Do all cells have primary and secondary cell walls?

A

No

25
Q

What is the structure of a secondary cell wall?

A
  • made up of multiple layers

- microfibrils in each layer have different orientations

26
Q

What are the chemical characteristics of the secondary cell wall?

A
  • more cellulose
  • less pectin
  • lignin
27
Q

What is lignin

A
  • second most abundant organic macromolecule
  • complex polymer
  • adds strength to cell wall by filling in the gaps between cellulose fibres + excludes water
28
Q

What cell types generally have a secondary cell wall?

A

water transporting cells

29
Q

How do cells with a cell wall communicate?

A

Plasmodesmata

30
Q

What are plasmodesmata?

A

intercellular connections that enable cell to cell communication

31
Q

What are the key features of plasmodesmata?

A
  • plasma membrane is continuous between cells
  • small enough to prevent organelle movements between cells although ER is connected through it
  • Allows for free exchange of small molecules

Cels191 (35 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions