Cell Structures

The Cell Theory  All living things are composed of cells.  Cells are the basic units of structure and function in living things.  New cells are produced from existing cells.

2 Basic Types of Cells  Prokaryotes (prokaryotic cells) –Cells that DO NOT have a nucleus –Examples: bacteria  Eukaryotes (eukaryotic cells) –Cells that DO have a nucleus and other organelles –Examples: plant cells and animal cells

Cell Structures  Specialized structures that perform specific functions in the cell are called organelles.  Organelle means “little organ”.

1 - Name: Cell Wall 2 - Picture – this should be an illustration that shows what the structure does; what is the function of the structure? NOT a picture straight from textbook. 3 - Description of the picture that you came up with; Example: the offensive line protects the quarterback. 4 – Function - How does your picture connect to the function of the cell part? Example: the cell wall is like the walls of the factory because it supports and protects the factory. 5 - Type - Plant or Animal cell; Prokaryote or Eukaryote; Example: found in all prokaryotes, fungi and, plant cells; NOT found in animal cells!!!

Cell Membrane  Physical Description: thin, flexible barrier around the cell (just inside the cell wall OR the outside border of animal cells)  Function: controls what enters and leaves the cell; support and protection  Type of Cell: found in all cells  Analogy: it is like the security guard of a factory

Cytoplasm  Physical Description: the fluid-like material inside the cell membrane  Function: contains the organelles; “cell jelly” –Site for chemical reactions  Type of Cell: found in all cells  Analogy: it is like the air of a factory

Nucleus  Physical Description: large organelle that is usually near the center; contains the cell’s genetic material (DNA) a boss controls his/her employees  Function: controls the cells activities and  Type of Cell: found in all eukaryotes  Analogy: it is like the boss of a factory

Nuclear Membrane (aka Nuclear Envelope)  Physical Description: double layered membrane that surrounds the nucleus; has pores  Function: Protects the nucleus; pores allow material in and out of the nucleus.  Type of Cell: found in all eukaryotes  Analogy: it is like the office of a factory

Endoplasmic Reticulum (ER)  Physical Description: internal membrane system  2 Types: Rough—has ribosomes Smooth—NO ribosomes  Function: Smooth—assembles components of the cell membrane; Rough—modifies proteins  Type of Cell: found in all eukaryotes  Analogy: it is like the assembly line of a factory

Ribosomes  Physical Description: very small, round structures either attached to the endoplasmic reticulum or free (floating in the cytoplasm)  Function: makes proteins  Type of Cell: found in all eukaryotes AND some prokaryotes  Analogy: it is like the workers in a factory

Golgi Apparatus  Physical Description: stack of membranes in the cytoplasm  Function: attaches carbohydrates and lipids to proteins; gives proteins the “address” of their final destination  Type of Cell: found in all eukaryotes  Analogy: it is like the mailroom or packaging department of a factory

Lysosome  Physical Description: small, round sacks in the cytoplasm  Function: breaks down lipids, carbohydrates, and proteins into useable molecules; break down old or damaged organelles  Type of Cell: found in all eukaryotes BUT are very rare in plant cells  Analogy: it is like the janitor of a factory

Vacuole  Physical Description: large, spacious sack in the cytoplasm  Function: stores materials for the cell (water, food, waste, etc…)  Type of Cell: found in all eukaryotes (usually one large vacuole in plants and many small vacuoles in animals)  Analogy: it is like the storage warehouse of a factory

Mitochondria  Physical Description: “bean-shaped” organelle that has a folded inner membrane (called cristae)  Function: use FOOD to make high- ENERGY compounds for use by the cell  Type of Cell: found in all eukaryotes  Analogy: it is like the power plant or coal-burning furnace of a factory

Chloroplast  Physical Description: tubular organelle that contains chlorophyll (a green pigment)  Function: use energy from SUNLIGHT to MAKE FOOD molecules through photosynthesis  Type of Cell: found in plant cells  Analogy: it is like the cafeteria OR solar energy panels of a factory

Cytoskeleton  Physical Description: a network of protein filaments in the cytoplasm; made of microtubules and microfilaments  Function: helps support the cell and maintain its shape; moves organelles within the cell; aids in cell movement  Type of Cell: found in all cells  Analogy: it is like the support beams and cranes of a factory

Centrioles  Physical Description: bundles of microtubules  Function: part of the cytoskeleton that aids in cellular division  Type of Cell: found in animal cells  Analogy: it is like the cranes used to move things in a factory

Plant Cells vs. Animal Cells  Cell Wall  Chloroplasts  No Centrioles  Lysosomes are rare  1 Large Vacuole  No Cell Wall  No Chloroplasts  Centrioles  Lysosomes are common  Several Small Vacuoles

Animal Cell

Plant Cell

Job of Cells  The main job of all cells is to make proteins  Different cells make different types  Protein production: –Ribosome  –Endoplasmic Reticulum  –Golgi Apparatus  –Final Destination of the Protein (may be outside of the cell)