Unit 1, AOS1, Chapter 2B: Cell Organelles (definitions)

Cytosol

The fluid within the cell

Cytoplasm

All the organelles (except the nucleus) and the cytosol together

Nucleus

The nucleus has a double membrane and protects and confines the cell's DNA

Nucleolus

The site of ribosome production

Ribosomes

Structures made of ribosomal RNA (rRNA) and proteins that translate messenger RNA (mRNA) to synthesise proteins (all cells contain ribosomes)

Rough Endoplasmic Reticulum (RER)

A membranous chain of connected and flattened sacs coated with ribosomes that can synthesise and modify proteins

Smooth Endoplasmic Reticulum (SER)

A membranous chain of connected and flattened sacs responsible for lipid production in the cell

Golgi Apparatus

The golgi apparatus is made up of stacked flattened sacsis the site of protein sorting, packaging, and modification for use in the cell or export.

Remember: post office of the cell

Lysosome

A membrane-bound containing digestive enzymes for breaking down cell waste, invasive viruses or bacteria and toxins

Mitochondrion

An organelle with a highly folded inner membrane (cristae) within an outer membrane, that is the site of aerobic cellular respiration to produce ATP (contains DNA and ribosomes)

Chloroplast

A double membrane-bound organelle that is the site of photosynthesis (contains DNA and ribosomes)

Vacuole

A membrane-bound sac used for water and solute storage, creating turgor pressure that maintains the plant cell structure.

Centrosome

A centrosome is made up of two centrioles. During meiosis and mitosis, the centrioles separate and move to opposite poles of the cell to efficiently organise the spindle fibres.

Plasma Membrane

A selectively permeable barrier between the intracellular and the extracellular environment that controls what goes in and out of the cell

Cell Wall

A sturdy border outside the plasma membrane that provides strength and structure to plant, bacterial, and fungal cells.

Vesicle

A small, membrane-bound sac that transports substances into or out of a cell, or stores substances within a cell.

Cytoskeleton

A network of protein filaments from the nucleus to the plasma membrane that maintains cell shape and transports vesicles around the cell.

Cilia and Flagella 

Protuberences from the cell membrane (flagella being longer than cilia) that allow the cell to move through fluid.

Identify three features that differentiate plant and animal cells

• A large central vacuole (plants only)

• Chloroplasts (plants only)

• Cell wall (plants only)

• Centrosomes (animal cells only)

• Lysosomes (animals cells only)