2.1: Cell Structure

Eukaryotic: membrane bound nucleus

Plant cells: cell wall, plastids, larger vacuole

Cytoskeleton: used for cell shape, internal structure, movement and cell division

Many cell are surrounded and supported by a complex extracellular matrix, able to interact with adjacent cells and environment via cell junctions.

Prokaryotes: no nuclear membrane, no mitochondria

Subunits of ribosomes are assembled from proteins and DNA in the nucleus

Name	Structure reference/ Analogy	Membrane?	Function
Nucleus	Pearl in an oyster.	Y	Contains & protects almost all the DNA - separated from cytosol or metabolic processes that may damage it. Makes ribosome units.
Endoplasmic Reticulum (ER)	Extension to nuclear envelope. Repeated, flat folds.	Y	Creates new polypeptide chains and sometimes enhances them into lipids or enzymes.
Golgi body	Stack of pancakes.	Y	Vesicles fuse and empty here. Put finishing touches on chains like phosphates and sugars to make membrane proteins and then shipped of to plasma membrane or lysosomes.
Transport/ Secretory vesicle	Marble-like structures.	Y	Transport within the cell or releases them from the cell.
Mitochondrion	Looks like a kidney bean or a small, wrapped baby.	Y	Own DNA. Makes ATP. Basically an aerobic bacteria that got comfortable.
Chloroplast	Two outer membranes with stroma inside. Stroma may look like stacks of coins.	Y	Contains enzymes, pigments and traces of DNA. Plastid.
Lysosomes	Recycling centers: hold digestive enzymes.	Y	Vesicle containing powerful digestive enzymes. Carry disposals.
Peroxisome	Recycling centers: Hold catlase	Y	Vesicle containing enzymes for digesting fatty or amino acids.
Vacuole	Garbage bins.	Y	Vesicle that stores waste and aids in cellular metabolism and water balance. Maintains pressure.
Ribosome	Folded ribbon.	N	Assemble polypeptide chains.
Centriole	Two pills or logs lying on top of each other.	N	Makes tubules for cell division.

Nuclear Membrane: Double membrane of 2 lipid bi-layers. Contains proteins that are receptors, transporters & spanners. Restricts access to DNA.
Nucleoplasm: vicious fluid similar to cytosol
Nucleolus: Dense, irregularly shaped region. Sub-units of ribosomes are assembled from proteins and RNA.
Chromatin: DNA & associated proteins in nucleus.

Plastids: membrane-bound organelle that is involved in photosynthesis and storage in plants and algae
- Chloroplast: double membrane, enzymes and pigments for photosynthesis - in stroma
- Chromoplasts: stores pigments other than chlorophyll
- Amyloplasts: stores starch

Visual Reference