Raw sap and processed sap

vascular plants

Just as human beings have a circulatory system, plants have another type of vascularization. Obviously, we are talking about vascular plants. It's about the raw sap and elaborated sap. In this case, this sap is the one that runs through the entire organism to nourish the plant. However, many people wonder what is the difference between them, the features and function.

For this reason, we are going to focus this article on telling you what raw sap and elaborated sap are and everything you need to know about them.

What is raw sap and elaborated sap

raw sap and elaborated sap ducts

The liquid substance transported through the conductive tissues of plants is called sap, one of the various plant tissues that exist. Thanks to the production of sap, plants can create their own food source. But what forms the juice? Plant juices contain a large amount of inorganic salts, amino acids and hormones. However, this liquid substance is composed mainly of water, specifically 98%, although this may vary from one species to another.

There are two types of sap in plants: raw sap and processed sap. The crude sap is characteristically formed in the roots and is transported through the xylem to the rest of the plant. After photosynthesis, it becomes elaborated sap, which It is transported by the phloem from the leaves to the roots in the opposite direction.

It is important to know that the production of sap in the vast majority of species coincides with periods of high temperature to improve the growth of our plants. For this reason, most of the pruning is done in winter to avoid the loss of this vital material for plant life.

types of sap

raw sap and processed sap

The sap is transported by the conductive tissues of the plant: xylem and phloem. Each of them is responsible for transporting two types of existing sap:

  • raw sap: It is a liquid substance formed after the roots absorb water and mineral salts. This is transported from the roots to the leaves in wooden containers.
  • Elaborated SAP: It is the result of the photosynthetic transformation of the raw juice. Thanks to the phloem, it is transported in the opposite direction, carrying food from the leaves and stems through conductive blood vessels until it passes through the vessels to the roots. The well-processed sap is a real food for plants, since it not only contains water and mineral salts, but also sugars and phytoregulators.

Main functions

xylem and phloem

These are the main functions of the sap:

  • The main function of the sap is nourish the plant so that it can develop and function properly.
  • The sap is responsible for transporting micro and macro elements to the leaves for photosynthesis, It carries food to all parts of the plant.
  • Once this substance is made into processed juice, it is not only used as food for the plant itself, but also as source of food for animals and even humans. In fact, certain types of sap produced by different plant species also have medicinal properties. Birch sap, for example, is known for this.
  • Thanks to the sap, plants can improve their own heat regulation through the transpiration of the leaves and stems of the plant.

The way the sap reaches the top is by transport against gravity thanks to the xylem. Through this conduit, the water and mineral salts captured by the roots of the tree from the soil itself are transported to finally reach all parts of the plant, including the treetops.

The xylem and the phloem are responsible for transporting the sap. The raw sap through the xylem has made the long journey through all the points it reaches, providing the necessary nutrients to the leaves, which are responsible for most of the photosynthesis, thus turning it into the elaborated sap. Rich in carbohydrates, this is transported by the phloem, another conduit responsible for ensuring the transport of nutrients. Eventually, this elaborated sap will take the opposite route to carry food to the rest of the plant. From the roots, through the trunk, to the foliage that covers the crown.

Differences between raw sap and processed sap

The crude sap is the one that is transferred by the xylem and is made up of water, mineral elements, growth regulators and other dissolved substances. It moves from the roots to the leaves through strong tubes. It is made up of water and different inorganic mineral salts, which the roots extract from the soil through the root hairs and transport it through woody or ascending vessels called xylem. This sap is transferred to the leaves where photosynthesis converts it into elaborated sap. The way in which this sap was transported has caused much controversy.

On the other hand, the elaborated sap is transported by the phloem from the origin of its formation, in leaves and green stems towards the roots. It is made up of water, sugars, amino acids, vitamins, organic acids, dissolved minerals and plant regulators.

Transport of the elaborated sap

The pressure flow hypothesis is used as the delivery technique of the elaborated sap. The pressure flow hypothesis explains the displacement of the elaborated sap, since the movement of the fluid in the phloem is determined by the use and production of sugar. It was proposed in this hypothesis that the hydrostatic pressure differentials created by osmosis lead to the movement of the sap produced from the sources (mature leaves and roots that store material) down to the sinkholes (root tips, unfolded leaves, flowers and organs).

Sucrose and other nutrients manufactured by the chlorophyll parenchyma cells enter the phloem companion cells in the leaf veins by active transport and, once there, move by diffusion to the sieve tubes. Inside the sieve, the increase in solutes causes water to enter from the xylem vessels by osmosis. When water enters, the hydrostatic pressure inside the tube increases, pushing the sap produced by the phloem.

Once you reach the sink, sucrose is pumped into cells and used to form storage molecules such as starch or cellulose, which are structural molecules. As sucrose decreases on the sieve, water seeps into the xylem vessels, causing a drop in hydrostatic pressure.

The difference in hydrostatic pressure between the source and the sink, created by osmosis, is what causes the brewed sap to move from the source to the sink.

I hope that with this information you can learn more about raw sap and elaborated sap

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