Bellringer-November 24, How does the cell in a tadpole compare to the size of a cell in a whale? 2.What makes a whale so much larger than a tadpole? (when it comes to cells) 3.What types of organisms are prokaryotes? (guess!) 4.What types of organisms are eukaryotes? (guess!) 5.What is the difference between prokaryotes and eukaryotes? (guess!)

Prokaryotes vs Eukaryotes Honors Biology

Cell Theory 1. All living things are made of cells 2. Cells are the basic unit of life 3. All existing cells are produced by other living cells. 3 Nerve cells in the retina by Santiago Ramon

FIRST TO VIEW CELLS In 1665, Robert Hooke used a microscope to examine a thin slice of cork (dead plant cells) What he saw looked like small boxes

FIRST TO VIEW CELLS Hooke is responsible for naming cells Hooke called them “CELLS” because they looked like the small rooms that monks lived in called Cells

CELLS! Smallest unit of life in all living things Two basic types: 6 Prokaryotic – Simple Smaller No membrane- bound organelles No nucleus MAY have a cell wall Ex: Bacteria Eukaryotic – More complex Membrane- bound organelles Ex: Plants, Animals, and Fungi

CELL TYPES Three Basic types of cells include: Animal Cell (Eukaryote) Plant Cell (Eukaryote) Bacterial Cell (Prokaryote) **SMALLEST

8 CELL SIZE Typical cells range from 5 – 50 micrometers (microns) in diameter copyright cmassengale

NUMBER OF CELLS Although ALL living things are made of cells, organisms may be: Unicellular – composed of one cell Multicellular- composed of many cells that may organize into tissues, etc.

ALL CELLS… Contain 4 basic cell structures: Cell Membrane Cytoplasm Ribosomes DNA **not an organelle

PROKARYOTES – THE FIRST CELLS Simplest and smallest type of cell – Includes bacteria NO nucleus NO/FEW organelles 1 Single, circular chromosome Think: “Pro” athlete plays with 1 ball

PROKARYOTES Nucleoid region (center) contains the DNA (NO nulceus) Surrounded by cell membrane & cell wall (made of peptidoglycan) Contain ribosomes in their cytoplasm to make proteins Flagella for movement

Prokaryotes Prokaryotes: (pro- means before, and -karyote means nucleus) – First type of cells to evolve – Very small (size of mitochondria) – Unicellular – Two Types: 1)Archaea 2) Eubacteria – Cell Division/Reproduction: Asexual via Binary Fission

Prokaryote Cell Structure Components: cell membrane cell wall ribosomes flagella nucleoid region (NO NUCLEUS) cytoplasm capsule pili NO membrane-bound organelles

Functions Capsule - Found in some bacterial cells, this additional outer covering protects the cell, and helps the cell adhere to surfaces and nutrients. Cell Wall - Outer covering of most cells that protects the bacterial cell and gives it shape. Cytoplasm - A gel-like substance composed mainly of water that also contains enzymes, salts, cell components, and various organic molecules. Cell Membrane or Plasma Membrane - Surrounds the cell's cytoplasm and regulates the flow of substances in and out of the cell. 15

Function cont’d Pili - Hair-like structures on the surface of the cell that attach to other bacterial cells. Flagella - Long, whip-like protrusion that aids in cellular locomotion. Ribosomes - Cell structures responsible for protein production. Nucleiod Region - Area of the cytoplasm that contains the single bacterial DNA molecule. 16

17

EUKARYOTES All eukaryotic cells HAVE: a Nucleus membrane-bound organelles These cell types includes: protists fungi plants animals More complex type of cells

Eukaryotic Cells Divided into compartments Unicellular or Multicellular Organelles → structures that have a specific function in the cell (including the nucleus) Cytoplasm → region between nucleus and plasma membrane that surrounds organelles – Filled with cytosol (watery-jelly part) and organelles – Contains centrioles, which help with cell division  reproduction 19

20 Organelles Organelles are individual structures that have specific functions. Together, these organelles carry out the necessary jobs in order for that cell to survive. Many other things are organized in this way as well. Very small (Microscopic) Perform various functions for a cell Found in the cytoplasm May or may not be membrane-bound copyright cmassengale

Types of Eukaryotes Unicellular (Protozoa) – Protists Paramecium, amoebae – Fungi Yeast Multicellular (Metazoa) – Fungi – Plants – Animals Reproduction for ALL eukaryotes may be asexual or sexual

Features in Common between Eukaryote & Prokayrote Both eukaryote and prokaryote cells have these features in common: 1) Surrounded by a plasma/cell membrane This determines what enters and leaves the cell It is thin and flexible and does not provide much structural support Ex: school doors 2) Have RIBOSOMES MAKES proteins by linking amino acids (protein synthesis) 3) Have DNA or RNA as genetic material 22

TWO MAIN TYPES OF EUKARYOTIC CELLS Plant Cell Animal Cell

Exit Slip-November 24, 2014 Draw your own prokaryotic cell and label the following: (KNOW THIS WITHOUT LOOKING AT YOUR NOTES LATER ON): – Cell membrane – Flagella – Cytoplasm – Cell wall – Nucleoid Region – Capsule – Pili – Ribosomes