Endocytosis (endo = internal, cytosis = transport mechanism) is a general term for the various types of active transport that move particles into a cell by enclosing them in a vesicle made out of plasma membrane.

Endocytosis is the process of capturing a substance or particle from outside the cell by engulfing it with the cell membrane, and bringing it into the cell. Exocytosis describes the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell.

Pinocytosis (“pino” means “to drink”) is a process by which the cell takes in the fluids along with dissolved small molecules. In this process, the cell membrane folds and creates small pockets and captures the cellular fluid and dissolved substances.

In cellular biology, pinocytosis, otherwise known as fluid endocytosis and bulk-phase pinocytosis, is a mode of endocytosis in which small particles suspended in extracellular fluid are brought into the cell through an invagination of the cell membrane, resulting in a suspension of the particles within a small vesicle …

Examples of Pinocytosis An example of pinocytosis is observed in the microvilli of the small intestine to absorb nutrients from the lumen of the gastrointestinal tract. Similarly, it is also observed in cells in the ducts of the kidneys during the formation of urine.

Examples of Pinocytosis Microvilli in the gut use this process to absorb nutrients from food. Cells in the kidney can use pinocytosis to separate nutrients and fluids from the urine that will be expelled from the body. In addition, human egg cells also use it to absorb nutrients prior to being fertilized.

Phagocytosis (the condition of “cell eating”) is the process by which large particles, such as cells or relatively large particles, are taken in by a cell.

What is pinocytosis? While phagocytosis involves the ingestion of solid material, pinocytosis is the ingestion of surrounding fluid(s). This type of endocytosis allows a cell to engulf dissolved substances that bind to the cell membrane prior to internalization.

Pinocytosis is an example of endocytosis (a cellular process in which substances are brought inside a cell). Examples of endocytosis include phagocytosis and pinocytosis.

Examples of Phagocytosis White blood cells are known as “professional” phagocytes because their role in the body is to find and engulf invading bacteria. Ciliates are another type of organisms that use phagocytosis to eat. Ciliates are protozoans that are found in water, and they eat bacteria and algae.

As nouns the difference between endosome and phagosome is that endosome is (biology) an endocytic vacuole through which molecules internalized during endocytosis pass en route to lysosomes while phagosome is a membrane-bound vacuole within a cell containing foreign material captured by phagocytosis.

Phagocytosis is a process wherein a cell binds to the item it wants to engulf on the cell surface and draws the item inward while engulfing around it. The process of phagocytosis often happens when the cell is trying to destroy something, like a virus or an infected cell, and is often used by immune system cells.

There are four essential steps in phagocytosis: (1) the plasma membrane entraps the food particle, (2) a vacuole forms within the cell to contain the food particle, (3) lysosomes fuse with the food vacuole, and (4) enzymes of the lysosomes digest the food particle.

The process of phagocytosis begins with the binding of opsonins (i.e. complement or antibody) and/or specific molecules on the pathogen surface (called pathogen-associated molecular pathogens [PAMPs]) to cell surface receptors on the phagocyte. This causes receptor clustering and triggers phagocytosis.

The Steps Involved in Phagocytosis

• Step 1: Activation of the Phagocyte.
• Step 2: Chemotaxis of Phagocytes (for wandering macrophages, neutrophils, and eosinophils)
• Step 3: Attachment of the Phagocyte to the Microbe or Cell.
• Step 4: Ingestion of the Microbe or Cell by the Phagocyte.

• Step 1: Activation of Phagocytic cells and Chemotaxis.
• Step 2: Recognition of invading microbes.
• Step 3: Ingestion and formation of phagosomes.
• Step 4: Formation of phagolysome.
• Step 5: Microbial killing and formation of residual bodies.
• Step 6: Elimination or exocytosis.

: orientation or movement of an organism or cell in relation to chemical agents.

Apoptosis induces cell surface changes that are important for recognition and engulfment of cells by phagocytes. The phagocytic removal of apoptotic cells does not elicit pro-inflammatory responses; in contrast, apoptotic cell engulfment appears to activate signals that suppress release of pro-inflammatory cytokines.

Major steps of apoptosis:

• Cell shrinks.
• Cell fragments.
• Cytoskeleton collapses.
• Nuclear envelope disassembles.
• Cells release apoptotic bodies.

Apoptosis is the process of programmed cell death. It is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand. In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair. Apoptosis also plays a role in preventing cancer.

That is, the cells activate an intracellular death programme and kill themselves in a controlled way — a process now known as programmed cell death, or apoptosis. Apoptotic cells shrink and are rapidly eaten by neighbouring cells, before there is any leakage of their contents.

Unsourced material may be challenged and removed. Inhibitors of apoptosis are a group of proteins that mainly act on the intrinsic pathway that block programmed cell death, which can frequently lead to cancer or other effects for the cell if mutated or improperly regulated.

Efforts to prevent excessive lymphocyte apoptosis during severe infection have focused either on modification of the signal processing system to create an inherent bias against the triggering of cell death pathways or on inhibition of caspase activity to block their execution.

Recently, starting from the observation that cancer cells that have defective checkpoints, often because of p53 pathway mutations, can still stop the cell cycle and avoid DNA damage-induced cell death by relying on the other checkpoint branches [33], a novel anticancer therapeutic strategy has begun to develop.

Defective apoptosis is associated with many types of illness including autoimmune diseases, neurodegenerative diseases bacterial and viral diseases, heart diseases, and cancer [42,43]. Several reports have linked autoimmune diseases directly to dysregulated apoptosis and impaired clearance of apoptotic cells [44–49].

In mammals, IAPs can also regulate apoptosis through controlling caspase activity and caspase-activating platform formation.

Caspases, a unique family of cysteine proteases, execute programmed cell death (apoptosis). Caspases exist as inactive zymogens in cells and undergo a cascade of catalytic activation at the onset of apoptosis. The activated caspases are subject to inhibition by the inhibitor-of-apoptosis (IAP) family of proteins.

Inhibitors of Apoptosis Proteins (IAPs) are a class of highly conserved proteins predominantly known for the regulation of caspases and immune signaling. However, recent evidence suggests a crucial role for these molecules in the regulation of tumor cell shape and migration by controlling MAPK, NF-κB and Rho GTPases.

An orally bioavailable second mitochondrial-derived activator of caspases (SMAC) mimetic and inhibitor of IAP (Inhibitor of Apoptosis Protein) family of proteins, with potential antineoplastic activity.