Cells

Structure: Double layer of lipids; embedded with proteins.

Function: An external cell barrier; acts in transport of substances in/out of cell.

• Structure: Part of cell that lies internal to plasma membrane, external to nucleus. Jelly like.
• Water, ions and enzymes.
• Function: The cytoplasm plays an important role in a cell, serving as a
• "molecular soup" in which the organelles are suspended and
• held together by a fatty membrane.

• Structure: Dense particles of two sub units; each composed of ribosomal RNA and protein; free or
• attached to rough ER.
• Function: The sites of protein synthesis.

• Structure: Membrane system enclosing a cavity, the cisterna, and coiling through the cytoplasm;
• externally studded with ribosomes.
• Function: Makes proteins that are secreted from the cell; makes the cell’s membranes.

• Structure: Membranous system of sacs and tubules; free of ribosomes.
• Function: Site of lipid and steroid synthesis, lipid metabolism and drug detoxification.

• Structure: A stack of smooth membrane sacs close to the nucleus.
• Function: Packages, modifies, and secretes proteins for secretion from the cell, inclusion in
• lysosomes

• Structure: Rod-like, double membrane structures; inner membrane folded into projections called
• cristae.
• Function: Site of ATP synthesis; powerhouse of the cell.

• Structure: Membranous sacs containing acid hydrolases.
• Function: Sites of intracellular digestion.

• Structure: Membranous sacs of oxidase enzymes
• Function: The enzymes detoxify a number of toxic substances; the most important enzyme,
• catalase, breaks down hydrogen peroxide

• Structure: Cylindrical structures made of tubulin proteins
• Function: Support the cell and give it shape. Involved in intracellular movements, form
• centrioles.

• Structure: Paired cylindrical bodies, each composed of nine triplets of microtubules.
• Function: Organize a microtubule network during mitosis to form the spindle and asters; form the
• bases of cilia and flagella.

• Structure: Surrounded by the nuclear envelope; contains fluid nucleoplasm, nucleoli and chromatin.
• Function: Control center of the cell; responsible for transmitting genetic information and
• providing the instructions for protein synthesis.

• Structure: Dense spherical (non-membrane bounded) bodies
• Function: Site of ribosome subunit manufacture.

• Structure: Granular, thread-like material composed of DNA and hystone proteins.
• Function: DNA constitutes the genes.