1 THE CELL The Smallest Unit of Life Alison Birkmeyer Copyright © Dale Carnegie & Associates, Inc.

2 THE CELL THEORY Observations by the following three people formed the cell theory. Schleiden- plants Schwann – animals Virchow - cells come from other cells

3 CELL THEORY 1. All Living Things are made up of one or more cells. 2. Cells are the basic units of structure and function in organisms. 3. All cells arise from preexisting cells

4 Looking at cells Robert Hooke – 1 st to see cells. (cork) Anton van Leeuwenhoek – living creatures (animalcules) Two types of microscopes Compound LIGHT - uses light and two or more lenses. Electron – uses a beam of electrons.

5 Compound Light Uses two or more lenses Uses light Low magnification View living or dead specimens Magnification= ocular lens X objective lens. ex. Ocular = 10x ; obj. lens = 10x Total magnification = (10 X 10) = 100x

6 Electron Microscope Uses a beam of electrons Specimens must be placed in a vacuum Cannot be used to view living things. Very powerful magnification Two types of electron microscopes are Transmission and Scanning

7 CELL SIZE Surface are is an important factor in limiting cell growth because The cell may become too large to take in enough food and to remove enough waste.

8 Common Features of ALL Cells Cell Membrane Cytoplasm Ribosomes Cytoskeleton DNA

9 Cell Types Prokaryote Eukaryote

10 Prokaryote Functions are controlled by the DNA Plasmid not the nucleus (NO NUCLEUS) Modern prokaryotes (most or majority) are generally known as BACTERIA

11 Prokaryote No internal membrane bound organelles Do NOT have a nucleus Oldest cell types –Their evolution preceded that of eukaryotes Most are unicellular bacteria Ex. Old Kingdom Monera (BACTERIA)

12 EUKARYOTE All other organisms (except bacteria) are eukaryotes The cells of Animals; Plants, Fungus, Protists are Eukaryotic (you are an Eukaryotic) Specialized structures called organelles that perform a specific function Only eukaryotic cells have membrane bound organelles

13 EUKARYOTE A cell with a well defined nucleus surrounded by a nuclear envelope is an EUKARYOTE EUKARYOTE cells have a system of internal membranes

14 CELL MEMBRANE Gate keeper- Allows materials to enter and leave Structure that regulates what enters and leaves the cell All substances that enter or leave a cell must cross the cell membrane Is selectively permeable – allows only some things to pass in or out. Encloses the contents of the cell

15 CYTOSKELETON Provides the internal framework of a cell Mesh like network of protein fibers that supports the shape of the cell Microtubules – highway system Microfilaments - support structures

16 CYTOPLASM Gel-like substance found within the cell Supports the cell Region of the cell within the membrane that includes the fluid; cytoskeleton; and all of the organelles except the nucleus

17 CELL ORGANELLES (Know ALL of these & functions) 1Nucleus 2Ribosomes 3Endoplasmic Reticulum (rough and smooth) 4Golgi apparatus 5Lysosome9. Chromosomes 6Mitochondria10. DNA 7Vesicle or Vacuole11. Cell Wall 8Centrioles12. Plastids

18 NUCLEUS The nucleus houses a cell’s DNA, which contains heredity information. DNA stores information that directs the activities of the cell Has a double membrane surrounding the nucleus called the nuclear envelope

19 NUCLEUS Contains chromosomes Chromosomes are rod shaped structures that are made up of DNA and protein

20 RIBOSOMES Site of PROTEIN synthesis in a cell In the cell, proteins are made on the RIBOSOMES Free (found floating in the cytoplasm Attached (attached to ER)

21 ENDOPLASMIC RETICULUM Helps to maintain homeostasis by moving substances from one parts of the cell to another Rough ER has RIBOSOMES embedded on its surface. Smooth ER has no ribosomes embedded

22 Golgi Apparatus Packaging and distribution center of the cell

23 LYSOSOME Organelle that contains digestive enzymes that breaks down cellular materials (CHO; proteins, nucleoc acids, lipids, etc…) Referred to as a suicide sac Waste management system Digests and recycles cellular components

24 MITOCHONDRIA POWER HOUSE (ENERGY) Mitochondria contain DNA Produces most of the cell’s energy Stores this energy in cpds called ATP More energy requirements – more mitochondria Ex. Muscle cells have more that skin cells

25 CHLOROPLASTS (PLANTS) Use light energy to make CHO (sugar) Glucose. The main organelle associated with plant photosynthesis. Site of Photosynthesis Contain their own DNA Thought to be descendants of prokaryotic cells.

26 CELL WALL NOT FOUND IN ANIMAL CELLS Support and protection for plants, bacteria, and fungi

27 CILIA and FLAGELLA Cilia – shorthair like structures that protrude from the surface of a cell and are packed in tight rows (movement) Flagella – long whip like structure used for movement

28 Major differences between PLANT and ANIMAL cells PLANT: has the following –Chloroplasts/Chlorophyll –Large central vacuole –Cell Wall = made of cellulose –Plant cells are surrounded by a CELL WALL PLANT:do NOT have –Centrioles

29 Animal Cells vs Plant cells KNOW Animal cells do NOT have a cell wall Animal cells do NOT have Chloroplasts Animal cells do NOT have a central vacuole – they have smaller vesicles Animal cells have Centrioles

30 What identifies a cell as an Eukaryote? –The nucleus Chromosomes are found in the? –NUCLEUS Recognize an animal cell because(Main Reasons? –NO CELL WALL –NO CHLOROPLAST

31 DRAW and LABLE ANIMAL CELL 1.Nucleus7. Nuclear Membrane 2.Mitochondria8. Cytoplasm 3.ER9. Chromosomes (DNA) 4.Lysosome10. Ribosomes 5.Golgi Apparatus 6.Cell Membrane

32 DRAW and LABLE PLANT CELL 1.Nucleus9. Nuclear Membrane 2.Central Vacuole10. Ribosomes 3.Cell Wall11. Golgi Body 4.Cell Membrane 5.ER 6.Chloroplast 7.Mitochondria 8.Chromosomes (DNA)