Lesson 1-1:
Animal and Plant Cells
Main Types of Cells
Main Parts of Cells
Difference
. . . .

Main Parts of Cells

Cytoplasm

  1. Endoplasmic reticulum — a set of interconnected tubes that start from the nucleus and snake through the cytoplasm. It is one of the places in the cell where proteins are made. It can be smooth (with no ribosomes attached) or rough (with attached ribosomes).
  2. Ribosomes — tiny particles that are made up of proteins and ribonucleic acid (RNA), one of the two acids found in cells and which transmits genetic information from the DNA to the proteins that the cells make. Some ribosomes are attached to the endoplasmic reticulum while others are suspended in the cytoplasm.
  3. Golgi apparatus — consists of flattened sacs that are arranged approximately parallel to each other. It refines the proteins that it receives from the endoplasmic reticulum then packages and modifies it before the proteins are delivered to various parts of the body. It also produces the microbodies.
  1. Cytoskeleton — the cell’s framework that provides it with shape and structural support. It is made up of microfilaments, microtubules, and intermediate filaments.
  2. Centrioles — small, dark structures found in animal cells that play an important role in mitotic cell division. They have been observed to exist in algae and fungi and in a few reproductive cells of higher forms of plants.
  3. Vacuoles — membrane-enclosed, fluid-filled spaces consisting of crystals, inorganic salts, and sugars.
  4. Microbodies — made up of the peroxisomes, glyoxysomes, and lysosomes. The peroxisomes and glyoxysomes are vesicles that contain oxidative enzymes that catalyze the removal of amino acids. The lysosomes are made up of digestive enzymes. These microbodies are believed to occur in all animal cells after having been discovered in rats and fungi.

The third major part of the cytoplasm is made up of inclusions, which are nonliving components of the cell that are suspended in the cytosol. They are basically made up of starch and glycogen granules and are used for storing energy for the cell. Among the inclusions are lipids, glycogen, crystals, and pigments.