Algonquin College
2.1 - Review of Cell Structure and Function
Cells are the basic unit of life. Organisms are composed of many different cell types organized into tissues, organs and organ systems.

The cell cycle controls the reproduction of cells. It consists of the S phase, a phase of growth and preparation, and the M or mitotic (cell division) phase. Mitosis occurs during the M phase, and involves five stages: Interphase, Prophase, Metaphase, Anaphase and Telophase. At the end of mitosis, a single parent cell has produced two identical daughter cells that contain the same genetic information as the parent cell.

In sexual reproduction, a special type of cell division called meiosis occurs. In meiosis, two cell divisions occur, resulting in four daughter cells. Each daughter cell only contains one half of the genetic information of the parent cell, and each daughter cell contains a unique combination of genetic information.

Table 2.1 - Organelles and their functions

Part Function
Nucleus Contains the genetic material (chromatin; condensed DNA) that directs cell activities. Surrounded by a double-layered membrane with pores.
Nucelolus Forms the components of ribosomes
Ribosome Manufactures proteins from mRNA templates
Vesicle Membrane-bound sacs for the storage and transport of molecules
Rough endoplasmic reticulum Folded plasma membrane studded with ribosomes; manufacture of proteins and glycoproteins
Smooth endoplasmic reticulum Folded plasma membrane free of ribosomes; manufactures lipids, detoxifies substances in the cell
Golgi apparatus Modifies cell products from other organelles and tags them for export. Forms lysosomes and secretory vesicles.
Lysosome Engulfs particles in the cytoplasm and breaks them down into usable monomer units
Peroxisome Contains products to oxidize molecules and manufactures bile salts
Mitochondrion Folded inner membrane surrounded by an outer membrane. Breaks down carbohydrates to produce ATP (energy).
Cytoskeleton Filaments that provide support and movement for the cell with the aid of ATP and motor proteins.
Plasma membrane Phosopholipid bilayer; selectively permeable with a hydrophilic surface and hydrophobic core. Studded with proteins, carbohydrates, glycoproteins, cholesterol and other molecules in a “fluid mosaic”.

To review the parts of cells and their functions use the activity below.

Activity 2.1: Cell Organelles