Plant Physiology and Nutrient Uptake

Microscopic pores on the surface of leaves that facilitate gas exchange between the plant and the atmosphere.

The process of water movement through a plant and its evaporation from aerial parts, primarily leaves.

The uptake of carbon dioxide (CO2) from the atmosphere by plants for photosynthesis.

The loss of water vapor from plant tissues, primarily through the stomata.

The balance between CO2 uptake and water loss through the stomata.

Loss of turgor pressure in plant cells, leading to wilting.

The internal pressure within plant cells, maintained by water uptake.

The cooling effect of transpiration, which helps plants regulate their temperature.

The Venus flytrap closes its trap in less than 0.1 seconds after two sensory hairs on its leaves are triggered within 20 seconds.

The Venus flytrap needs to be stimulated twice within a short time period to close its trap.

The Venus flytrap does not close its trap when treated with an anesthetic. This suggests plants have a memory similar to humans.

The Venus flytrap's ability to remember past stimuli suggests that plants possess a form of memory.

The scientific study of how changes in the concentration of hydrogen ions (protons) across a membrane are used to perform work, such as generating ATP.

The ability of a plant to adjust its characteristics based on the environment. For example, a plant growing in high light will develop more stomata to maximize carbon dioxide uptake.

Tiny pores on the surface of leaves that regulate gas exchange, allowing carbon dioxide in for photosynthesis and water vapor out for transpiration.

The number of stomata per unit area of leaf surface. Plants growing in high light often have higher stomatal density to optimize photosynthesis.

Special cells surrounding stomata that control their opening and closing, allowing the plant to regulate gas exchange and water loss.

The process of opening and closing stomata, allowing plants to regulate their water loss and carbon dioxide uptake.

A process that involves the uptake and release of potassium ions (K+) by guard cells, altering their water content and thus controlling stomatal opening and closing. This process requires energy (ATP).

A photosynthetic pathway in which the first stable product is a four-carbon compound. It is often found in plants adapted to hot, dry environments, allowing them to capture more carbon dioxide with less water loss.

A photosynthetic pathway in which carbon dioxide is taken up at night and stored as an organic acid, allowing the plant to photosynthesize during the day with minimal water loss.

Chemical elements absorbed from the soil as inorganic ions. Necessary for a plant to complete its life cycle.

The elements required in large amounts by plants for growth and development. These include carbon, oxygen, hydrogen, nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium.

The elements required in small amounts by plants for growth and development. These include chlorine, iron, manganese, boron, zinc, copper, nickel, and molybdenum.

A mutualistic relationship between plant roots and fungal hyphae. The fungi help the plant absorb nutrients and water from the soil, while the plant provides the fungi with carbohydrates.

Extensions of epidermal cells on plant roots that increase the surface area for nutrient and water absorption.

A continuous network of cell walls and extracellular spaces in plant tissues, allowing for the movement of water and dissolved substances.

A continuous network of cytoplasm connected by plasmodesmata in plant tissues, allowing for the movement of water and dissolved substances within the cells.

The process by which plant roots selectively absorb nutrients from the soil through specialized membrane transport systems.

A membrane potential difference between the inside and outside of a plant cell, with the inside being more negative. This potential drives the uptake of positively charged ions like potassium (K+) into the cell.

Specialized proteins embedded in cell membranes that facilitate the transport of specific molecules across the membrane, either actively or passively.

A waxy layer in the cell walls of endodermal cells that blocks the apoplastic pathway for water and nutrients, forcing them to enter the symplast and allowing for selective uptake.

The central core of a root, located inside the endodermis, where water and nutrients are discharged into the vascular system (xylem).

A process where water is pushed upward through the xylem due to osmotic pressure, driven by the accumulation of salts in the stele. This is more important when transpiration is low, like at night or in humid conditions.

The main mechanism for long-distance water transport in plants, driven by negative pressure created by transpiration at the leaves. This pull is transmitted through the cohesive water molecules in the xylem.

Phloem sap is a fluid that moves throughout the plant, containing sugars, amino acids, and hormones. Sucrose is the primary sugar transported.

A specialized cell in the phloem that connects with other sieve-tube members to form a continuous transport system. These cells are alive but lack a nucleus and ribosomes.

A companion cell is a specialized cell located next to a sieve-tube member in the phloem, connected through plasmodesmata. They play a crucial role in regulating and facilitating the movement of nutrients within the phloem.

The mechanism of loading sucrose into phloem involves active transport against its concentration gradient using ATP. This process uses a chemiosmotic cotransport system with hydrogen ions.

The unloading of sucrose from phloem occurs at the sink, where it can be metabolised, converted into starch, or used for biosynthesis. This process leads to a decrease in pressure at the sink due to water loss.

The capacity of a plant to transport sugars out of the leaf is crucial for optimal yield. This process involves the coordinated functioning of phloem, sources, and sinks.