Transport in plants

Xylem sap movement speed

The speed at which xylem sap, the fluid that carries water and nutrients, can travel in plants, reaching up to 15 meters per hour.

Transpiration

The process by which plants lose water from their leaves to the atmosphere, which helps create a pull that moves water up through the plant.

Root pressure

The force generated in the roots of a plant that helps push water upward through the xylem.

Cohesion in water

The attraction between water molecules that makes them stick together, which is important for water transport in plants.

Adhesion in water

The ability of water molecules to stick to other surfaces, assisting in the movement of water within plant tissues.

Xylem cells

Specialized hollow cells, including tracheids and vessel elements, that are connected end to end to transport water throughout the plant.

Lignin in xylem walls

A water-repellent substance found in the cell walls of xylem cells, providing support and structure.

Transpiration-Cohesion-Tension Theory

A scientific explanation for how water is pulled up through xylem in plants as water evaporates from leaves.

Sources in phloem

Areas in the plant, such as leaves, where sugars are produced or stored, which are then transported through the phloem.

Sinks in phloem

Regions in the plant, such as roots and flowers, where sugars are utilized or stored.

Phloem loading

The process of adding sugars to the phloem, increasing pressure and allowing sap to be pushed into areas of need.

Water potential (y) in phloem

The measure of the ability of water to move within phloem, which decreases when solute concentration increases, promoting sap movement.

Guard cells

Special cells in the plant's epidermis that manage the opening and closing of stomata, the pores that allow gas exchange.

Stomatal pore function

The role of stomatal pores in controlling the exchange of gases like oxygen and carbon dioxide in plants based on the pressure of guard cells.

Turgidity in guard cells

The state of guard cells when they fill with water, causing them to swell and open the stomata.

Potassium ions (K+) in guard cells

Ions that, when they increase inside guard cells, help make the cells turgid and cause stomata to open.

ATP-driven proton pumps

Protein pumps that use energy to move hydrogen ions out of guard cells, facilitating the uptake of potassium and water.

Hydrostatic pressure in phloem

The pressure created from water entering phloem during the process of loading, which helps move the sap.

Transpiration pull

The force that results from water evaporating from leaves, which pulls water up through the plant's vascular system.

Mature maple trees

Large trees that can lose as much as 200 liters of water every hour through the process of transpiration.

Vessel elements

A type of hollow xylem cell that allows for rapid transport of water and nutrients.

Tracheids

Another kind of xylem cell, long and slender, that also facilitates the movement of water.

Hydrophobic lignin

The component in the walls of xylem cells that keeps water from leaking out, aiding in effective water transport.

Regulation of stomata

The control of stomata opening and closing by guard cells, which is essential for managing water loss and gas exchange.

Sources and sinks

Terms used to describe parts of the plant; sources are where resources like sugars are made, and sinks are where they are used.

High sucrose concentration

A condition in phloem where sugar levels are high, creating pressure that drives the movement of sap.

Double duty of plant organs

Some plant parts can serve both as sources (making sugar) and sinks (storing or using sugar) depending on the plant's needs.