Plant Biology: Auxins and Water Regulation

Auxin stimulates cell elongation by increasing the activity of proton pumps, making the cell wall more flexible.

The hypothesis explaining how auxin increases cell wall extensibility by decreasing pH, allowing the cell to expand.

Proteins that loosen the cross-linking in the cell wall, increasing its extensibility.

A pump that moves protons (H+) from inside the cell to the cell wall, decreasing the pH and making it easier for the cell to expand.

The ability of the cell wall to stretch and expand, allowing the cell to grow larger.

The process of plant development, involving factors like light, auxin, and cell elongation.

A plant hormone that controls cell elongation and other growth processes.

Directed plant growth in response to light.

A protein that senses light direction.

A light receptor involved in shade avoidance and other responses.

Different light wavelengths that affect plant responses, like stem elongation, germination etc.

Transporters that move auxin within plant cells.

Specialized cells that regulate stomata opening and closing, controlling gas exchange.

Pores on the surface of leaves that allow gas exchange like water and carbon dioxide.

The process where plant cells increase in length.

The total mass of living material in an organism or ecosystem.

Process by which plants convert light energy into chemical energy.

Process plants use to release energy from sugars.

The principle describing how mass is conserved in biological systems.

The boundary between the cell's interior and the surroundings, regulating what enters and exits.

The difference in electrical charge across a cell membrane, created by the unequal distribution of ions.

The continuous network of cell walls and extra-cellular spaces in a plant.

The continuous network of cytoplasm that connects plant cells.

The process where cellulose fibers in the cell wall separate, allowing for expansion and growth.

The movement of positively and negatively charged ions into and out of the symplast.

The tendency of water to move into a solution due to the concentration of solutes. A higher solute concentration results in a lower solute potential and more water moving in.

The pressure exerted by the cell wall on the cell's contents, pushing water out of the cell. A positive pressure potential means water wants to move out.

The overall tendency of water to move from one area to another. It combines solute potential and pressure potential.

Water potential gradient. Water moves from areas of high water potential to areas of low water potential.

Guard cells control the opening and closing of stomata, which are tiny pores on the surface of leaves. They respond to environmental stimuli like light and water availability to regulate transpiration.

It pumps hydrogen ions (H+) into the cell wall, making it more acidic. This acidification loosens the cell wall structure, making it easier for the cell to expand.

They have specialized receptors that detect changes in the environment. For example, photoreceptors in guard cells sense light, and their turgor pressure changes in response to water availability.

A series of events that allows a plant to respond to a stimulus. It involves signal reception, transduction, and a response.

A type of plant vascular tissue that primarily transports water and dissolved minerals upwards from the roots to the leaves. It's composed of dead cells connected end-to-end, forming long tubes.

The process by which plants lose water vapor from their leaves through tiny pores called stomata.

The difference in water potential between two regions, causing water to move from high potential to low potential, like water flowing downhill.

The force that pushes water upwards from the roots into the xylem, driven by active solute uptake by the root cells.

The difference in water potential between the soil and the atmosphere, creating a gradient that pulls water upwards. This is facilitated by transpiration, cohesion of water molecules, and adhesion to the xylem walls.

Factors such as light intensity, humidity, temperature, and wind speed can influence the rate at which water evaporates through stomata.

The attraction between water molecules due to hydrogen bonds, leading to surface tension and resistance to breakage.

A negative pressure potential within the xylem, created by transpiration and pulling water upwards.

This hypothesis explains how water moves upwards in plants. Transpiration creates tension in the xylem, and cohesion between water molecules allows the entire column to be pulled up.

The force at the surface of a liquid caused by cohesive forces, making the surface resist stretching or breaking.

The force of attraction between water molecules and other substances, allowing water to 'stick' to surfaces.

The pressure exerted by water inside a cell against its cell wall, influencing the opening and closing of stomata.

A plant hormone that promotes stomatal closure in response to water stress or other environmental cues.