Cellular Adaptation to Environmental Stress

A cell's ability to change its structure or function in response to external stimuli, enabling it to survive and thrive in different environments. These changes are reversible, meaning the cell can return to its original state once the stimulus is removed.

An increase in the size of a cell due to an increase in the number of cellular components, particularly proteins and organelles.

An increase in the number of cells within a tissue or organ due to increased cell division.

A decrease in the size and number of cells within a tissue or organ.

The transformation of one mature cell type to another mature cell type. This is a protective mechanism to better withstand environmental stress.

A type of cell injury that is reversible, meaning the cell can return to its normal state if the damaging stimulus is removed.

A type of cell injury that is irreversible, leading to cell death.

The point where an injury transitions from reversible to irreversible, causing the cell to die.

A process of programmed cell death that involves a series of biochemical events leading to the dismantling of the cell and the removal of its components by phagocytosis. This process is characterized by specific morphological and biochemical features.

A process of uncontrolled cell death caused by injury or damage to the cell that results in swelling, rupture, and inflammation. The release of intracellular contents can trigger an inflammatory response.

A type of cell injury caused by a lack of oxygen, which leads to a decrease in ATP production and can ultimately lead to cell death. The loss of oxygen can be due to ischemia, respiratory failure, or decreased blood oxygen-carrying capacity.

A crucial organelle in cells responsible for the production of ATP, the main energy currency used by cells to perform various functions.

A group of highly reactive molecules that can damage cells and contribute to various diseases. They are produced as a byproduct of normal metabolism and increased during cell stress or injury.

A pathway for ATP production that requires oxygen. It is the main energy-producing pathway in most mammalian cells.

A pathway for ATP production that does not require oxygen. It can produce ATP in anaerobic conditions, using glucose from the body fluids or glycogen breakdown.

The process of maintaining a stable internal environment within cells and organisms. It involves various mechanisms that regulate factors like temperature, pH, and ion concentrations.

Cells with high glycolytic capacity, like liver cells, can better cope with ATP depletion during oxidative stress due to injury. This is because they can rely on glycolysis to generate ATP even when oxidative phosphorylation is compromised.

Calcium homeostasis is maintained through storage in organelles like the mitochondria and ER. When disrupted, calcium levels rise, leading to various detrimental effects.

Reduced oxygen supply to cells (ischemia) and toxins can disrupt normal cellular function and lead to injury.

Elevated calcium levels open the mitochondrial permeability transition pore (mPTP), causing disruption of ATP production.

Increased calcium leads to activation of various enzymes, like phospholipases, proteases, and endonucleases, causing damage to cell membranes, proteins, and DNA.

Reactive oxygen species (ROS) are produced in various cellular compartments like the ER, mitochondria, and cytosol. They cause damage to lipids, proteins, and DNA, contributing to cell injury.

Antioxidant enzymes like superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH) protect cells from oxidative damage caused by ROS.

Persistent injury leads to biochemical and morphological changes in cells, ultimately resulting in cell death through necrosis.

Stress and its harmful effects on cells are initially detected at a biochemical and molecular level. There's a delay between the onset of stress and visible changes in cell injury or death, known as a "time lag". This delay varies depending on the cell's sensitivity and the observation method used.

Cells continuously adapt to maintain a balanced internal environment, reacting to changes within and outside the cell. This process, called cellular homeostasis, involves mechanisms for repair and restoration.

If the external environment becomes too extreme for too long, cells face a critical point where they decide whether to keep functioning or activate protective mechanisms.

When cells can't maintain normal function, they activate mechanisms like cell senescence (permanent aging) or programmed cell death (RCD). These mechanisms help regulate the overall health of the organism.

Cells adjust their behavior and functions in response to stressful conditions. This adaptation is crucial for survival in constantly changing environments.

The process of cellular aging, influenced by both genetic and environmental factors, leading to cell abnormalities and characteristic aging changes.

Cellular responses to stress are controlled by cell-extrinsic mechanisms that maintain homeostasis. These mechanisms operate locally and systemically, using "danger signals" to regulate cellular responses.

Signals that alert neighboring cells or the entire organism about potential dangers or threats. This communication happens through paracrine (local) or endocrine (system-wide) pathways.

The ability of certain plants, like resurrection plants, to survive extreme drought conditions, unlike non-resurrection plants.

Resurrection plants like Boea hygrometrica are able to survive severe drought by undergoing specific adaptations that allow them to maintain their water content.

A measure of the water content in a plant, indicating its hydration level.

A plant that does not have the ability to survive extreme drought conditions, like Arabidopsis thaliana.

The process of cell shrinking and membrane folding caused by water loss, a key step for survival in dehydration for plants.

Signaling pathways that activate the necessary protection and repair mechanisms in resurrection plants, mainly through changes within the cell walls.

A crucial cellular recycling process activated in resurrection plants to break down and remove damaged cellular components under dehydration.

The shutdown of photosynthesis as a survival mechanism in resurrection plants during dehydration, conserving energy and preventing damage.

An alternative energy pathway used in resurrection plants during dehydration, providing energy when photosynthesis is halted.

The outward manifestations of water loss in resurrection plants, including shrinking and curling of leaves, which help to reduce water loss and protect the plant.

The ability of resurrection plants to survive extreme dehydration and revive when water becomes available, a unique adaptation to arid environments.

The process of water loss that impacts the survival strategies of both resurrection and non-resurrection plants, leading to contrasting responses.