Animal Cells

This schematic represents an idealized animal cell, e.g., a liver cell. The columns to the left and right of the labels contain links to discussions of the particular structures.

Intermediate filaments

Plasma membrane

Peroxisome

Vacuole

Lysosome

Nucleolus

Centrioles

Nucleus

Nuclear envelope

Golgi apparatus

Pinocytotic vesicle

Actin filaments

Glycogen granules

Smooth endoplasmic reticulum

Microtubules

Ribosomes

Mitochondrion

Rough endoplasmic reticulum

Lysosomes and Peroxisomes

Lysosomes

Lysosomes are roughly spherical bodies enclosed by a single membrane. They are manufactured by the Golgi apparatus (pathway 2 in the figure).

Link to a discussion of how proteins synthesized in the endoplasmic reticulum are sent to the appropriate destinations.

They contain over 50 different kinds of hydrolytic enzymes including

The pH within the lysosome is about pH 5, substantially

Cell Membranes

One universal feature of all cells is an outer limiting membrane called the plasma membrane.

In addition, all eukaryotic cells contain elaborate systems of internal membranes which set up various membrane-enclosed compartments within the cell.

Cell membranes are built from lipids and proteins.

The Plasma Membrane

The plasma membrane serves as the interface between the machinery in the interior of the cell and the extracellular fluid (ECF) that bathes all cells.

The lipids