Cellular Organelles Overview

The nucleus is the cell's control center, containing most of the cell's DNA and directing protein synthesis via making mRNA. DNA is associated with proteins in structures called chromosomes. Each chromosome is composed of a single DNA molecule associated with proteins.

The nuclear envelope is a double membrane with pores allowing material to flow in and out of the nucleus. It's attached to the endoplasmic reticulum.

The nucleolus is a prominent structure in the nucleus responsible for ribosomal RNA (rRNA) synthesis.

Peroxisomes are single-membrane bound compartments that produce hydrogen peroxide and convert it to water. They perform reactions with diverse functions.

The cytoskeleton is a network of protein fibers providing structural support and enabling motility. It interacts with motor proteins for cellular regulation and movement

Microfilaments (actin filaments) are involved in cell shape and motility. They contain the protein myosin for movement.

Microtubules are hollow tubes, larger than microfilaments, involved in cell shape, movement, and vesicle transport. They are composed of tubulin protein

Centrosomes are microtubule-organizing centers in many cells, often containing a pair of centrioles in animal cells which are involved in cell division

Actin filaments are abundant in muscle cells and arranged in parallel lines. Their primary function is in muscle contraction.

Intermediate filaments provide structural support to cells, helping maintain their shape and anchoring organelles in place.

Microtubules, made of tubulin protein, provide rigidity to cells and act as tracks for moving organelles within the cell.

Muscle contraction involves the sliding of actin and myosin filaments past each other, powered by myosin motor proteins.

Cilia and flagella are hair-like projections found on some cells. They are composed of microtubules and aid in movement by bending.

Cilia and flagella have a characteristic 9 + 2 arrangement of microtubules, with a central pair surrounded by nine microtubule doublets.

The extracellular matrix (ECM) is a network of molecules outside animal cells, providing support, holding cells together, and acting as a barrier for the plasma membrane.

Integrins are proteins that connect the ECM to the cytoskeleton, providing a link between the cell's internal structure and its surroundings.

Specialized connections between adjacent cells that allow for communication, interaction, and adhesion. They create a functional unit by coordinating cellular activities.

Prevent leakage of extracellular fluid across a layer of epithelial cells. They act like tight seals.

Anchored to each other and to components of the extracellular matrix. They provide structural support and withstand mechanical stress.

Channels that physically connect adjacent cells, allowing the rapid exchange of small molecules. Important for communication and coordination.

A process that separates cells into their major organelles. Used to study the functions of different cellular components.

A mixture of broken-down cells with organelles released into the solution.

A method that uses a centrifuge to separate organelles based on their size and density. It uses different speeds and durations of centrifugation.

The liquid portion that floats on top of the pellet after centrifugation. Contains smaller organelles or components.

The solid mass of material that settles at the bottom of the centrifuge tube.

A complex of proteins and carbohydrates found on the exterior surface of the plasma membrane. They help in cell recognition and adhesion.