Cell Theory Cells were discovered by Robert Hooke in 1665 Observed Cork through a microscope There are three parts to Cell Theory All Living things are made up of one or more cells. The cell is the basic unit of structure, physiology, and organization in living things. Every cell arises from pre-existing cells.

Cells are the basic unit of Life Cells are organized into tissues Tissues are groups of cells that work together Tissues are organized into organs and organ systems Cells Tissues Organs and Organ Systems

Cells are the basic unit of Life Adipose Tissue A Human Heart is an Organ

Cells Arise from Pre-Existing Cells Unicellular Organisms Contain only one Cell Production of a new cell results in a new organism Multicellular Organisms New cells arise for growth or to replace old damaged cells

Prokaryotic and Eukaryotic Cells Prokaryotic Cells Found in bacteria and archaea Eukaryotic Cells Found in all other organisms Plants and Animals

Prokaryotic and Eukaryotic Cells Prokaryotes Lack a membrane-bound nucleus and organelles DNA is free floating in the cytoplasm in circular chromosomes in a region called the nucleoid Nucleoid lacks a membrane Ribosomes are found in prokaryotic cells Involved in Protein Synthesis Cells are enclosed by a cell membrane Barrier to unwanted chemicals Involved in Communication with other cells Most prokaryotic cells have a Cell Wall as well

Prokaryotic and Eukaryotic Cells Eukaryotes Found in Plants, animals, fungi, and Protists Contain organelles enclosed in membranes Organelles are subcellular structures that perform specific tasks for the cell DNA is contained in a nucleus

Animal Cell Organelles

Nucleus All Eukaryotic cells contain a nucleus Contains DNA Occupies 20% of the volume of the cell Covered by a double layered membrane called a Nuclear Envelope Has pores that allow the transport of molecules in and out of the nucleus DNA is organized into chromosomes in the nucleus C’somes consist of DNA, proteins, and some RNA Makes a complex called Chromatin

Nucleus Functions of the Nucleus Include: Organization of DNA Protection of DNA Expression of DNA Nucleolus Where ribosomes are made Ribosomes are made of RNA Important for making proteins

Endoplasmic Recticulum (ER) Rough Endoplasmic Recticulum Site of Protein synthesis Contains ribosomes on its surface Smooth Endoplasmic Recticulum Produces lipids Detoxifies chemicals Transports materials throughout the cell Smooth ER Lacks Ribosomes

Golgi Apparatus Modifies and packages proteins that were made from the ER and sends them to other parts of the cell

Mitochondria Power house of the cell Inner membrane forms folds called cristae Increases surface area Functions of Mitochondria Supply Energy for the cell Through a process called Cellular respiration . Process where Oxygen combines with food molecules and releases energy. In the form of ATP (Adenosine Triphosphate)

Cytoskeleton Function of the Cytoskeleton Helps maintain cell shape Important for transporting molecules Important in cell division The cytoskeleton is made of three types of protein fibers: Microfiliments Intermediate Filiments Microtubles

Cell Membrane Separates the inside from the outside of the cell Made of fat molecules called phospholipids Creates a phospholipid bilayer Each phospholipid has hydrophobic (water fearing) tails and a hydrophilic head (water loving)

Other Animal Organelles Lysosomes: Structures that contain digestive enzymes Vacules: Fluid Filled structures that store nutrients, water, and waste Usually larger in plant cells Centrosomes Cylindrical structures found in animal cells Involved in cell division Peroxisomes Contain enzymes for metabolic reactions

Cilia and Flagella Cilia Used for: Cell Movement Moving substances Sensory Devices Flagella Longer than cilia Whip like movements propel the cell

Plant Cell Organelles Plant Cells have a Cell wall Made of cellulose Functions: Support Protection Chloroplasts Produces sugars for the plant through a process called photosynthesis Larger Vacuole Maintain pressure to keep plant upright Shortage of water causes vacuoles to shrink Plant wilts

Assignment: 7-1 and 7-2 Page 173 1-5 Page 181 1-5

ACTIVITY Get into groups of 3-4 people On one sheet of paper write down each person in your group Comme up with an analogy that you could compare to the cell and its organelles For Example: “The cell is like a factory.” Once your group has an analogy list specific organelles and how the function of the organelle relates to your analogy For Example: “The Golgi Apparatus is like the mail room of the factory. It receives proteins (mail) from the ER and delivers it to where it needs to go in the cell (factory).