Cells are the foundational level of organization of life. An organism may be unicellular, as with prokaryotes and most eukaryotic protists, or…

The size of cells varies widely among and within organisms. For instance, the smallest bacteria are 0.1 micrometers (μm) in diameter—about a…

One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles—such as the nucleus and…

Prokaryotes are small unicellular organisms in the domains Archaea and Bacteria. Bacteria include many common organisms such as Salmonella and…

The cytoplasm consists of organelles, an aqueous solution called the cytosol, and a framework of protein scaffolds called the cytoskeleton. The…

The nucleus is a membrane-bound organelle that contains a eukaryotic organism’s genetic instructions in the form of chromosomal DNA. This is…

The Endoplasmic Reticulum (ER) in eukaryotic cells is a substantial network of interconnected membranes with diverse functions, from calcium storage…

Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells…

As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are…

There are three types of cytoskeletal structures in eukaryotic cells—microfilaments, intermediate filaments, and microtubules. With a diameter…

Mitochondria and peroxisomes are organelles that are the primary sites of oxygen usage in eukaryotic cells. Mitochondria carry out cellular…

Multicellular organisms employ a variety of ways for cells to communicate with each other. Gap junctions are specialized proteins that form pores…

In order to maintain tissue organization, many animal cells are surrounded by structural molecules that make up the extracellular matrix (ECM).…

Cells with similar structure and function are grouped into tissues. A group of tissues with a specialized function is called an organ. There are four…

The plant cell wall gives plant cells shape, support, and protection. As a cell matures, its cell wall specializes according to the cell type. For…

The organs in a multicellular organism’s body are made up of tissues formed by cells. To work together cohesively, cells must communicate. One…

Analysis of the mitochondrial structure-function relationship is required for a thorough understanding of the regulatory mechanisms of mitochondrial…

Membrane proteins serve important functions in cells such as nutrient transport, motility, signaling, survival and virulence, yet constitute only ~1%…

Gene engineering in mouse embryos or embryonic stem cells (mESCs) allows for the study of the function of a given protein. Proteins are the…

Exosomes are small vesicles ranging in size from 30 nm to 100 nm that are released both constitutively and upon stimulation from a variety of cell…