Lysosome Without Labels – Blank Diagram to Print

All 10 parts on the diagram

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Start here: 4 main parts 4

Membrane Keeps the lysosome's contents apart from the rest of its cell. A single membrane, a phospholipid bilayer.
Lumen The acidic space inside. It is about pH 4.5 to 5, while the cytosol round it is about pH 7.2.
Hydrolytic enzymes Over 60 different hydrolases that work best in acid. They break proteins, fats, sugars and nucleic acids down into their building blocks.
Lysosome Full of enzymes that digest what the cell no longer needs. A small membrane-bound organelle, a few hundred to a cell.

In the membrane: 3 3

Glycocalyx A coat of sugar chains on the membrane's proteins, lining the inside. It protects the membrane from the lysosome's own enzymes.
Proton pump A pump in the membrane, a V-ATPase, that pushes hydrogen ions in. That is what keeps the inside acidic.
Transport protein Lets broken-down building blocks out into the cell to be used again. A protein in the membrane.

Where it comes from and what it meets: 4 3

Golgi apparatus Enzymes made in the endoplasmic reticulum are tagged here. They are sent off in vesicles to become part of lysosomes.
Phagosome A bubble of membrane round something the cell has swallowed. That could be a bacterium. The bubble fuses with a lysosome to be digested.
Autophagosome A double membrane wrapped round a worn-out part of the cell. Here it holds a mitochondrion. It fuses with a lysosome in autophagy, or self-eating.

How this list was compiled: Read 2026-09-27. Wikipedia, Lysosome, https://en.wikipedia.org/wiki/Lysosome : a membrane-bound organelle limited by a single phospholipid bilayer; the membrane carries heavily glycosylated proteins forming a glycocalyx that protects it from the enzymes inside; over 60 hydrolases, which need an acidic pH of about 4.5 to 5.0, against the cytosol's 7.2; a proton pump (V-ATPase) in the membrane moves protons into the lumen; products are exported through membrane transporters or vesicles to be reused; hydrolases are made in the endoplasmic reticulum, tagged with mannose-6-phosphate in the Golgi apparatus and sent in vesicles; lysosomes fuse with phagosomes and with autophagosomes carrying damaged organelles (autophagy); several hundred per cell. Licence: own work

The drawing: Drawn for this site by script, 2026-09-27. Own work, nothing traced. Licence: own work

How it works

This unlabeled diagram of a lysosome is two drawings on one sheet. Above, one lysosome cut open. Below, a small lysosome between the stack that supplies it and the two sacs it fuses with. Ten label lines want a name.

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The ten names on the unlabeled lysosome diagram

Six belong to the large lysosome: membrane, lumen, hydrolytic enzymes, glycocalyx, proton pump and transport protein. Four belong to the lower drawing: Golgi apparatus, lysosome, phagosome and autophagosome.

Which shape takes which name

Above, the thick ring is the membrane and the space inside it is the lumen. The notched discs are the enzymes, and the branched twigs lining the ring are the glycocalyx. The dark block at the top right is the proton pump; the pair of pale blocks at the bottom is the transport protein. Below, the stack of curved sacs is the Golgi apparatus, the sac holding a rod is the phagosome, and the one with a double outline is the autophagosome.

The small balls and the two arrows are hydrogen ions going in and digested products coming out. They take no name.
Two lines end on what a sac holds, a bacterium and a mitochondrion. The names wanted are the sacs: phagosome and autophagosome.
The name lysosome itself goes on the small round sac in the middle of the lower drawing.

Questions and answers

What does a lysosome look like?

A small sac with a single membrane, usually round or oval and now and then a tube. Its shape and size change with what it is digesting. The sheet draws it as a circle, cut open to show the inside.

Are lysosomes in plant cells?

Rarely. Lysosomes are in every animal cell except red blood cells, and an animal cell normally holds hundreds of them.

Where is the lysosome located on a cell diagram?

In the cytosol, the fluid that fills the cell around the nucleus and the other organelles. This sheet shows no whole cell. The animal cell diagram on this site shows a lysosome in place among the other organelles.

What is a phagolysosome?

What a phagosome becomes once it has fused with a lysosome: the sac where the enzymes break down what the cell swallowed. An autophagosome that has fused with a lysosome is an autolysosome. The sheet shows the sacs before they fuse.