Cell structure and function

Nucleus

Contains the cell’s DNA (genetic code) surrounded by a double layered membrane called the nuclear envelope. Within the nucleus in the nucleolus, which is where ribosomes are assembled.

Endoplasmic reticulum (ER)

A network of cisternae and tubules which link with the cell membrane and other membranous organelles including the nucleus.

Cisternae

Membrane-bound structures found in the endoplasmic reticulum, responsible for the synthesis and modification of proteins and lipids.

Tubules

Cylindrical structures within the endoplasmic reticulum that transport materials and are involved in various cellular processes.

Smooth Endoplasmic reticulum (SER)

A type of endoplasmic reticulum that lacks ribosomes and is primarily involved in lipid synthesis, metabolism of carbohydrates, and detoxification of drugs and poisons.

Rough endoplasmic reticulum (RER)

A type of endoplasmic reticulum that has ribosomes attached to its surface, to produce proteins. Once the proteins are made, enzymes in the endoplasmic reticulum add sugar molecules to form glycoproteins. Then, from the rough endoplasmic reticulum, proteins move into the Golgi apparatus for export out of the cell.

Golgi apparatus

Stack of flattened cisternae which, unlike the rough endoplasmic reticulum, are unconnected. Transport vesicles form at each cisternae to transport proteins made by the rough endoplasmic reticulum into the cystol or out of the cell via a process called exocytosis.

Mitochondria

Double membrane-bound organelles which are the sites of aerobic respiration, whereby ATP is produced.

Chloroplast (only plant cells)

Organelles found in plant cells, fungi, and protists that produce glucose through the process of photosynthesis.

Lysosomes (only animal cells)

Specialised vesicles which contain enzymes that digest (break down) waste or unwanted materials.

Vacuole

A fluid filled, membrane bound organelle that can contain waste products or help with water balance in plants.

Ribosomes

Sites of protein synthesis where mRNA is translated into proteins. Ribosomes are either bound to RER or floating free in the cytoplasm.