Cell Theory and Organelles: Eukaryotic vs Prokaryotic Cells

The cell theory

• A cell is the basic unit of life
• Organisms are made up of cells
• new cells arive from other cells

4.1

• Cells are small because they need to be for purposes of efficiency
• big cells are slow, small cells are efficient

Two types of microscopes

• compound light- it transmits image through your eye by light.
• electronic - through scanning to get every little detail.

two types of cells

• eukarya: an eukaryotic Eukaryotic cells are larger than prokaryotic cells and have a "true" nucleus, membrane-bound organelles, and rod-shaped chromosomes.
• prokaryotic: Prokaryotes lack an organized nucleus and other membrane-bound organelles.

organelles

• the small structures that make up a cell; each organelle performs a special function to
• help the cell do its job for the organism.
• 2. Some of the most important jobs in the cell include making and transporting proteins, releasing
• energy from food, controlling what enters and leaves the cell, and getting rid of wastes. While plant and animal cells have several of the same organelles, there are some structures that are
• found only in plants and not in animals. Many of the organelles found in cells are made up of or are surrounded by membrane and, therefore,
• would not be found in prokaryotic cells.
• II. Organelles Found in Typical Eukaryotic Cells

cell membrane

• Type of cell: both plant and animal
• Location: forms outer boundary of cell; surrounds cytoplasm; separates the cell from its environment
• Description: made up of a double layer of fats (called lipids) with some proteins scattered throughout;
• the proteins form tiny openings or passageways in the membrane called pores
• Function: 1. controls what moves into and out of the cell (only certain materials can get in or out; ex.
• food, oxygen, and materials go in and wastes and cell products move out)
• 2. provides protection and support for the cell
• Other: it is flexible so it can change shape under pressure; by allowing things to move in and out, it
• helps maintain homeostasis

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