BIO.A.1 Basic Biological Principles Bio.A.1.1 - Explain the characteristics common to all organisms Bio.A.1.2 Describe relationships between the structure & function at biological levels of organization
BIO.A.1 Basic Biological Principles Bio.A.1.1.1 Describe the characteristics of life shared by all prokaryotic and eukaryotic organisms Bio.A.1.2.1 Compare cellular structures & their functions in prokaryotic and eukaryotic cells Bio.A.1.2.2 Describe & interpret relationships between structure & function at various levels of biological organization
The Cell Theory Cells are the basic unit of life All living things are made of cells Plants, animals, bacteria, etc. Cells are the basic unit of structure and function in living things Can you give an example from your own body? New cells are produced only from existing cells
Microscopes We use various types of microscopes to see into and study cells We will use a compound light microscope Uses light and 2 lenses to create an image of the cell Can only magnify the image about 1000 times Not every part of a cell can be clearly seen with a light microscope Electron microscopes use a beam of electrons and offer much higher resolution can be used to study cell structures that are one billionth of a meter in size!
Microscopes There are 2 types of electron microscopes Transmission electron microscopes produce images that are flat and 2 dimensional because the specimen must be cut into ultra-thin slices Scanning electron microscopes produce 3 dimensional images of the specimen s surface Electron microscopes require the specimen to be preserved & placed in a vacuum which means only non-living cells and tissues can be examined
What Do You Think? What type of microscope would you use to examine cellular life in a drop of pond water? Why? What type of microscope would you use to examine the surface of the nucleus? Why? You are presented with a specimen to examine. What are two questions you could ask to determine the best microscope to use?
Prokaryotes and Eukaryotes There are a variety of cells, but all cells have a few characteristics in common All cells (at some point) have DNA (genetic material) All cells have a cell membrane (flexible barrier) All cells have cytoplasm (watery substance) All cells have proteins and ribosomes (structure that makes proteins) All cells (living things) grow, reproduce, obtain and use materials/energy, maintain a stable internal environment and respond to their environment
Prokaryotes Prokaryotes are generally smaller and simpler than eukaryotes Prokaryotic cells do not separate their genetic material into a nucleus They do not have specialized organelles ALL prokaryotes are single celled organisms Bacteria are prokaryotes
Typical Prokaryote What type of microscope do you think would be best to use to examine a typical prokaryotic cell? Why?
Eukaryotes Eukaryotes are generally larger and much more complex than prokaryotes Eukaryotic cells contain many highly specialized internal structures (organelles) One organelle is called the nucleus Eukaryotes store DNA inside the nucleus. Some eukaryotes are single celled (amoeba) and some are multicellular (us)
Eukaryotes Not all eukaryotic cells are the same but there are many parts most or all have in common Nucleus where the DNA is stored Ribosomes make the proteins, also found in prokaryotes
Eukaryotes Rough Endoplasmic Reticulum modifies proteins and is studded with ribosomes How is the rough ER s structure related to its function? Smooth Endoplasmic Reticulum synthesizes membrane lipids and detoxifies drugs What human organ would you expect to have large amounts of smooth ER?
Eukaryotes Golgi Apparatus modifies, sorts and packages proteins from the rough ER Vacuoles membrane bound storage facilities for the cell, often large and filled with water in plants
Eukaryotes Lysosomes membrane bound and filled with enzymes, for breaking down large molecules or older cell parts Centrioles help organize cell division, in animal cells but not plant cells
Eukaryotes Cytoskeleton helps the cell maintain its shape and also helps control cell movement
Eukaryotes Mitochondria convert chemical energy stored in food (glucose) into more useful chemical energy (ATP) Chloroplasts found in plant but not animal cells, convert light energy into chemical energy (glucose)
Eukaryotes Cell membrane all cells have a cell membrane, a fluid-mosaic, phospholipid bilayer that is selectively permeable
Eukaryotes Cell wall provides extra rigid support and protection for the cell, most are porous, not found in animal cells
What do you think? The cell has been compared to a city. Can you determine which cell part would be most like the following parts of a city and why? City Hall Post Office Factories Streets and Highways Recycling Plant Water Tower