Cell Organelles and Functions

microtubules

Microtubules are conveyer belts inside the cells. They move vesicles, granules, organelles like mitochondria, and chromosomes via special attachment proteins. They also serve a cytoskeletal role. Structurally, they are linear polymers of tubulin which is a globular protein.

cell wall

The cell wall surrounds the plasma membrane of plant cells and provides tensile strength and protection against mechanical and osmotic stress. It also allows cells to develop turgor pressure, which is the pressure of the cell contents against the cell wall.

Rough Endoplasmic Reticulum

The rough endoplasmic reticulum has on it ribosomes, which are small, round organelles whose function it is to make proteins for the rest of the cell to function.

cell membrane

a double layer of lipids and proteins that surrounds a cell; separates the cytoplasm (the contents of the cell) from the external environment; in both prokaryotic and eukaryotic; gives the cell its structure and regulates the materials that enter and leave the cell (selectively permeable)

lysosome

a membrane-bound cell organelle that contains digestive enzymes. Lysosomes are involved with various cell processes. They break down excess or worn-out cell parts. They may be used to destroy invading viruses and bacteria.

Vacuole

a membrane-bound cell organelle. In animal cells, vacuoles are generally small and help sequester waste products. In plant cells, vacuoles help maintain water balance. Sometimes a single vacuole can take up most of the interior space of the plant cell.

Smooth Endoplasmic Reticulum

a membrane-bound network of tubules without surface ribosomes. sER is not involved in protein synthesis. Its main function is the synthesis of lipids, steroids, and carbohydrates, as well as the metabolism of exogenous substances, such as drugs or toxins.

Golgi apparatus

a membrane-bound organelle found in most cells. It is responsible for packaging proteins into vesicles prior to secretion and therefore plays a key role in the secretory pathway.

Cytoskeleton

a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement.

Microfilamets

assist with cell movement and are made of a protein called actin. Actin works with another protein called myosin to produce muscle movements, cell division, and cytoplasmic streaming. Microfilaments keep organelles in place within the cell.

vesicle

compartments formed by a lipid bilayer separating its contents form the cytoplasm or a fluid-based extracellular environment; contain either liquids or gases and have a wide range of function in cells across the living world from regulating buoyancy to secreting hormones; derives from Latin, meaning "small bladder" and can also refer to blisters in the body or gas bubbles in volcanic rocks

nucleus

controls and regulates the activities of the cell (e.g., growth and metabolism) and carries the genes, structures that contain the hereditary information. Nucleoli are small bodies often seen within the nucleus.

nucleolus

dynamic membrane-less structure whose primary function is ribosomal RNA (rRNA) synthesis and ribosome biogenesis

chloroplast

found only in algal and plant cells; cell organelle that produces energy through photosynthesis - take light energy and convert it into a usable form that powers activities; It has a high concentration of chlorophyll and gives many plants and algae a green color; thought to have evolved from once free-living bacteria; comes from the Greek words khloros, meaning "green", and plastes, meaning "formed"

ribosomes

have two main functions — decoding the message and the formation of peptide bonds. These two activities reside in two large ribonucleoprotein particles (RNPs) of unequal size, the ribosomal subunits. Each subunit is made of one or more ribosomal RNAs (rRNAs) and many ribosomal proteins (r-proteins).

Mitochondria

membrane-bound cell organelles (mitochondrion, singular) that generate most of the chemical energy needed to power the cell's biochemical reactions. Chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP).

centrioles

paired barrel-shaped organelles located in the cytoplasm of animal cells near the nuclear envelope. Centrioles play a role in organizing microtubules that serve as the cell's skeletal system. They help determine the locations of the nucleus and other organelles within the cell.

cytoplasm (eukaryotic)

refers to the fluid that fills the cell, which includes the cytosol along with filaments, proteins, ions, and macromolecular structures as well as the organelles suspended in the cytosol; in eukaryotic cells, cytoplasm refers to the contents of the cell with the exception of the nucleus and have elaborate mechanisms for maintaining a distinct nuclear compartment separately; active transport is involved in the creation of these subcellular structures and for maintaining homeostasis