Objectives 1. Describe and explain the three parts of the cell theory 1. Describe and explain the three parts of the cell theory 2. Determine why cells are so small 2. Determine why cells are so small 3. Compare and contrast the structure of Prokaryotic and Eukaryotic Cells 3. Compare and contrast the structure of Prokaryotic and Eukaryotic Cells 4. Describe the structure of the cell membrane 4. Describe the structure of the cell membrane

Cell Features

Group Challenge What are 5 characteristics of the cell? What are 5 characteristics of the cell? Why are cells so small? Why are cells so small?

Group Challenge How are cells made? How are cells made? What do cells make up? What do cells make up? What protects the cell? What protects the cell?

Cell Theory Schleiden, Schwann, and Virchow Schleiden, Schwann, and Virchow 1. All living things are made of one or more cells 1. All living things are made of one or more cells 2. Cells are the basic units of structure and function 2. Cells are the basic units of structure and function 3. All cells arise from existing cells 3. All cells arise from existing cells

Common Features of Cells Cell Membrane – encloses the cell and separates the cell interior from outside the cell. Regulates what comes in and out of the cell. Cell Membrane – encloses the cell and separates the cell interior from outside the cell. Regulates what comes in and out of the cell. Cytoplasm – region of cell within the membrane that includes the fluid, cytoskeleton, and all organelles except the nucleus. Cytoplasm – region of cell within the membrane that includes the fluid, cytoskeleton, and all organelles except the nucleus.

Common Features of Cells Cytoskeleton – the cytoplasmic network of protein filaments that play a role in cell movement, shape, and division. Cytoskeleton – the cytoplasmic network of protein filaments that play a role in cell movement, shape, and division. Ribosomes – a cell organelle composed of RNA and protein synthesis. Ribosomes – a cell organelle composed of RNA and protein synthesis.

Prokaryotes Smallest and simplest cell Smallest and simplest cell Single celled, lacks a nucleus and other internal compartments Single celled, lacks a nucleus and other internal compartments Therefore can’t carry out many specialized functions Therefore can’t carry out many specialized functions Example BacteriaExample Bacteria

Characteristics of Prokaryotes Can Exist in a broad range of environments Can Exist in a broad range of environments Enzymes and Ribosomes are free to move around in the cytoplasm. Enzymes and Ribosomes are free to move around in the cytoplasm. No internal structures to divide the cell No internal structures to divide the cell Single circular molecule of DNA Single circular molecule of DNA Have a cell wall that provides structure and support and made of polysaccharides Have a cell wall that provides structure and support and made of polysaccharides Cell wall can be surrounded by a capsule which enables cell to cling to other objects Cell wall can be surrounded by a capsule which enables cell to cling to other objects

Characteristics of Prokaryotes Many Prokaryotes have a flagella. Many Prokaryotes have a flagella. Flagella – a long threadlike structure that protrude from the cells surface. Flagella – a long threadlike structure that protrude from the cells surface. What is the function of a flagella What is the function of a flagella

Prokaryotic Cell

Eukaryotic Cells The first cells with compartment The first cells with compartment Eukaryotic Cells have a nucleus Eukaryotic Cells have a nucleus Nucleus is an internal compartment that houses the cells DNANucleus is an internal compartment that houses the cells DNA The Eukaryotic Cell has membrane bound organelles The Eukaryotic Cell has membrane bound organelles Eukaryotic cell DNA is organized into chromosomes Eukaryotic cell DNA is organized into chromosomes Large Ribosomes Large Ribosomes

Cytoskeleton Provides the interior framework of an animal cell Provides the interior framework of an animal cell

3 Types of Cytoskeleton Fibers Actin Fibers – Play a major role in determining the shape of animal cells by pushing and pulling Actin Fibers – Play a major role in determining the shape of animal cells by pushing and pulling Microtubules – Act as a highway system for transportation of information from the nucleus to different parts of the cell Microtubules – Act as a highway system for transportation of information from the nucleus to different parts of the cell Intermediate Fibers – Provide a frame on which the ribosomes and enzymes can be confirmed to specific regions of the cell. Intermediate Fibers – Provide a frame on which the ribosomes and enzymes can be confirmed to specific regions of the cell.

The Cell Membrane Cell membranes are not rigid but fluid Cell membranes are not rigid but fluid Fluidity is caused by lipids which form the foundation Fluidity is caused by lipids which form the foundation Selectively Permeable Selectively Permeable Made of Phospholipids Made of Phospholipids

Phospholipids Lipid made of a phosphate group and two fatty acids. Lipid made of a phosphate group and two fatty acids. Polar Head and Two Non-Polar tails Polar Head and Two Non-Polar tails Phospholipids arranged in a bi-layer Phospholipids arranged in a bi-layer