Transport in plants - Phloem.

Translocation

The movement of a substance from one place to another, specifically referring to the movement of phloem sap from source to sink in plants.

Phloem Sap

A fluid that consists of assimilates like sucrose and amino acids, produced in the mesophyll cells of the leaves.

Source

A place in a plant where a substance, such as sucrose, is produced or loaded for transport.

Sink

A place in a plant where a substance is unloaded, either for use or storage.

Companion Cells

Cells that support sieve tube elements in the phloem, providing them with energy for transport.

Sieve Tube Elements

Larger conducting cells in phloem responsible for transporting assimilates from sources to sinks.

Hydrostatic Pressure

The 'pushing' force on water due to the pressure in a closed vessel.

Osmotic Pressure

The 'pulling' force on water due to the presence of solutes in solution.

Plasmodesmata

Channels that facilitate movement of substances between plant cells, including phloem sap.

Pressure Flow Theory

A theory that explains how sap moves through the phloem; it involves pressure gradients created by differences in sucrose concentration.

Callose

A polysaccharide made of beta-glucose produced by plants to seal wounds in sieve tubes.

Apoplast Pathway

The route that water and solutes take through the cell walls and spaces between cells.

Sieve Plates

Structures that add support to sieve tubes and have pores to allow flow of phloem sap.

Assimilates

Substances that are produced during photosynthesis and transported through the phloem.

Mitochondria

Organelles found in companion cells that provide energy for the transport of sucrose.

Xylem

Vascular tissue responsible for transporting water and minerals from roots to leaves; operates in one direction.

Microscope Slides

Prepared samples used for observing plant tissues, including phloem and xylem.

Ringing Method

A method of investigating the movement of solutes in stems by removing a ring of bark.

False-color SEM

A technique used to visualize structures at a microscopic level, often used in plant biology studies.