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2 Cells are… The extremely tiny building blocks of living things.

3 So, if they are extremely tiny… How do we know they are there? You only get one guess…

4 toolstechnology In science, the tools (or technology) often must be invented before we can make new discoveries. Cells were discovered and studied after the invention of microscopes… Euglena Amoeba Plant Cells (or tissue) Animal Cells (or Tissue) How were cells first discovered, named, and studied?

5 Antony van Leeuwenhoek ( ) 1665 – Robert Hooke designed the compound microscope that enabled scientists to see the microscopic world. He is credited with discovering and naming “cells.” He described what he observed. The boxlike cells of cork reminded him of the cells of a monastery walls, which in fact were the cells in cork tissue Hooke’s early compound microscopes could not magnify objects more than twenty or thirty times natural size. Leeuwenhoek was skilled at grinding lenses. This allowed him to build microscopes that magnified over 200 times. These microscopes had clearer and brighter images than any of his colleagues’ microscopes. Although he could not draw well, he hired an illustrator to prepare drawings of the things he saw to accompany his written descriptions. Robert Hooke Microscope Practice…Click HERE! A Brief History of the Microscope and the Beginnings of Microbiology Leeuwenhoek’s Microscope

6 Botanist Matthias Schleiden ( ) Anatomist Théodore Schwann (1810 – 1882) Schwann extended Schleiden's cell theory to animals Schleiden observed that all plants seemed to be composed of cells Schleiden and Schwann: Schleiden and Schwann:  proposed that all plants and animals were made of cells.  observed organisms that were unicellular and multicellular.  observed common cell structures such as membranes and nuclei.  made comparisons of various animal and plant tissues. Better Microscopes Led to the Development of the Cell Theory…

– While experimenting with diseases he found that all cells come from other existing cells. Thus, he completed what is known as the cell theory: “cells give rise to other cells; even multicellular organisms begin as single cells.” Physician / Pathologist Rudolph Virchow( ) Plant cell division Animal cell division

8 Schleiden, Schwann, and Virchow contributed to The Cell Theory: 3. New cells come from existing cells. 2. Cells are the basic units of structure and function in living things. 1. All living things are made up of one or more cells.

9 The 20 th century brought many technological advances that allowed scientists to better understand the structure and function of cells... such as the scanning electron microscope (SEM). The SEM produces magnified images like this one that scientists can use to study cells in more detail. Technological Advances

10 Cell Basics Certain structures are common to most eukaryotic cells: nucleus - control center cell membrane - outer boundary of the cell cytoplasm - material between the cell membrane and the nucleus cell wall – some cells have this strong layer around the cell membrane

11  Contains genetic material  Directs the making of proteins  Manages cell activities Nucleus Proteins Manager & Design Team mRNA&Co

12 Cytoplasm Cytoplasm - material between the cell membrane and the nucleus Endoplasmic Reticulum Golgi Apparatus Mitochondria Lysosomes Vacuoles Ribosomes Organelles in the Cytoplasm Chloroplasts

13 Into Fuel  Chloroplasts use the energy from sunlight to make energy-rich food molecules in a process known as photosynthesis. Makes Fuel Food/Energy Chloroplasts In Plant Cells and Energy Producing Protists Chloroplasts In Plant Cells and Energy Producing Protists

14 Power Generator  Function: Changes food energy into high-energy compounds called ATP a cell can use  The cell can use the energy to power growth, development, and movement. ATP ATP Mitochondria Mitochondria ATP ATP

15 Protein … Design to Product. Ribosomes The code to make proteins is sent to the ribosomes and proteins are constructed. The manufacturing of proteins is perhaps the most important function of the cell. Endoplasmic Reticulum Transports materials in the cell Golgi Bodies Modifies, sorts, packages, and transports substances in the cell Mitochondria Exports proteins to their final destination Chloroplasts (or other food energy)

16 Garbage Collectors  Filled with enzymes that aid in the disposal of the cell’s wastes  Break down and digest materials Lysosomes

17 Vacuoles  Animal cells lack a large central vacuole but may contain smaller vacuoles. Storage Tanks  Most plant cells have a large central vacuole filled with liquid.  Vacuoles are saclike structures that store materials such as water, salts, proteins, and carbohydrates.

18 Cell Membrane Allows what enters and leaves the cell Aids in protection & support Maintains balance Gate Keeper

19 Homeostasis  The cell membrane functions as a semi-permeable barrier - like a fence.  This means it allows some molecules in and out while preventing others from crossing. The Cell Membrane: Keeping Internal Conditions in Balance

20 Cell Wall  Cell walls provide support and protection.  Plants, algae, fungi, and nearly all prokaryotes have cell walls.

21 Chloroplast Mitochondria Ribosomes Endoplasmic Reticulum Nucleus Vacuole Golgi Bodies Lysosome Ribosomes often are on the E.R. This is a package” breaking away to be for exporting

22 Proteins Ribosomes Endoplasmic Reticulum Golgi Bodies Lysosome Vacuole Mitochondria Chloroplast Nucleus

23 Specialization of Cells  In multi-cellular organisms, cells are uniquely suited to perform a particular function.  Certain cells are specialized to move, react, protect, or produce special substances.

24 Levels of Organization  In multicellular organisms, cells are organized to form tissues.  Several types of tissues form organs.  Many different organs form organ systems that make up the organism. Organ Systems Organs Tissues Cells Organism