PLANT LIFE PROCESSES

Photosynthesis

The manufacture of sugars and their precursors by green plants in the presence of light and chlorophyll.

Stomata

Small openings on leaves that allow carbon dioxide to enter from the air.

Xylem

The vascular tissue responsible for transporting water from the roots to the sites of photosynthesis.

Chloroplast

The main organelle involved in photosynthesis, typically lens-shaped and bounded by a double membrane.

Granum

A stack of thylakoids within the chloroplast, involved in the light-dependent reactions of photosynthesis.

Chlorophyll

The principal pigment in photosynthesis, located between adjacent thylakoids, essential for light absorption.

Calvin Cycle

A pathway for fixing and reducing CO2 into carbohydrates, requiring ATP and NADPH from the light reactions.

C4 Pathway

A photosynthetic pathway that uses PEP as a CO2 acceptor, producing 4-carbon organic acids.

CAM Pathway

A photosynthetic adaptation found in succulent plants where CO2 is fixed at night and used during the day.

Factors Affecting Photosynthesis

Internal factors include enzymes, genetic factors, and water content; external factors include light, CO2 availability, and temperature.

Glycolysis

The first stage of respiration occurring in the cytoplasm, converting glucose into pyruvic acid and producing ATP.

Krebs Cycle

A stage of respiration where pyruvic acid is oxidized to CO2, generating NADH, FADH2, and ATP.

Electron Transport System

The final stage of respiration occurring in the inner mitochondrial membrane, where ATP is produced via oxidative phosphorylation.

Transpiration

The loss of moisture from plants in the form of water vapor, essential for hydration and nutrient transport.

Stomatal Transpiration

The process accounting for up to 90% of water loss from plants through stomata.

Soil-Plant-Air Continuum

The movement of water from soil to roots, through xylem to leaves, and finally to the atmosphere.

Translocation

The long-distance transport of photoassimilates from sources (producing organs) to sinks (consuming organs).

Assimilation

The process of utilizing food for growth, involving the conversion of substances into simpler compounds for cellular use.

Sink Strength

The ability of a sink to accumulate assimilates, influenced by its size and activity.

Vascular Connections

The nature of connections between source and sink organs that affects the movement of assimilates.