Why do phloem and xylem not contain starch?

  • Thread starter Lim Y K
  • Start date
In summary, phloem and xylem do not contain starch because sugars like glucose and sucrose are more soluble in water, making them easier to transport. However, there are some species that have starch in their underground stems and leaves, which suggests that starch may be moved around in the phloem in certain plants. This is likely to account for the buildup of starch in the underground stem, as it is a storage product for photosynthetic sugars.
  • #1
Lim Y K
26
0
Why do phloem and xylem not contain starch?
 
Biology news on Phys.org
  • #2
The phloem transports sucrose that is converted to starch elsewhere. The xylem transports mostly water.
 
  • Like
Likes Lim Y K
  • #3
Looking at it from a different "why":

Starches are not very soluble in water, so dissolving and transporting them in water is not likely. Sugars like glucose and sucrose are soluble.

Actually this a great question. There are species that have starches in underground stems and some starch in the leaves. A priori, you would expect starch to be moved around in phloem in such a plant, at least, to account for getting the starch buildup in the underground stem, since starch is a storage product for photosynthetic sugars.
 
  • Like
Likes Lim Y K

FAQ: Why do phloem and xylem not contain starch?

Why do phloem and xylem not contain starch?

Phloem and xylem are specialized vascular tissues responsible for transporting water, minerals, and organic compounds throughout a plant. They do not contain starch because their main function is to transport substances, not store them.

Do phloem and xylem have different roles in a plant?

Yes, phloem and xylem have different roles in a plant. Xylem transports water and minerals from the roots to the rest of the plant, while phloem transports organic compounds, such as sugars, from the leaves to other parts of the plant.

Why is starch stored in other parts of the plant instead of in phloem and xylem?

Starch is stored in other parts of the plant, such as roots, stems, and fruits, because these organs have the necessary cells and structures for starch storage. Phloem and xylem have specialized cells that are not suitable for storing large amounts of starch.

Can plants survive without phloem and xylem?

No, plants cannot survive without phloem and xylem. These tissues are essential for the transport of water, nutrients, and organic compounds throughout the plant. Without them, the plant would not be able to grow or develop properly.

How do phloem and xylem work together to transport substances?

Phloem and xylem work together through a process called translocation. Xylem transports water and minerals from the roots to the leaves, while phloem transports organic compounds, such as sugars, from the leaves to other parts of the plant. This allows for a constant supply of nutrients and water to all the cells in the plant.

Back
Top