The Cell 9/4/09

Cont’d From Yesterday Units of Small Measurement Micrometer (µm ) Scientific Notation is written as 1×10−6 m Nanometer (nm) Scientific Notation is written as 1×10−9 m Angstrom (Å or A) Scientific Notation is written as 1×10−10 m http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/

The Cell Theory Produced by Schleidon, Schwann, and Virchow All living things are made of one or more cells Cells are the basic units of structure and function in organisms All cells arise from existing cells

Cells must be small Average cell size = 5-20 µm Surface area to volume ratio must be high Therefore, substances don’t need to travel as far to reach the center of the cell (Basketball vs. Tennis ball)

Basics of All Cells Cell membrane- encloses the cell and regulates what goes in and out. Cytoplasm- the interior of the cell Cytoskeleton- micro-fibers inside the cytoplasm Ribosomes- make proteins DNA- provides instruction for making proteins, regulates cellular activity, and enables cells to reproduce

Two types of cells Prokaryotes Eukaryotes

Prokaryotes Single-celled Lacks a Nucleus and Organelles Has a Cell wall Ex: Bacteria

Eukaryotes Has a Nucleus Has Organelles Ex: Animal cell, Human cells

Cell Movement Flagella Cilia

We Have Cilia in Us

The Cell Membrane Selectively Permeable Phospholipid bilayer What does that mean? Phospholipid bilayer That’s a big name, lets break it down… A Phosphate Head and Two Fatty Acid Tails Bilayer means two layers

Movement In and Out Proteins stuck inside the Membrane. Proteins are made out of what that allows them to stay inside the cell membrane? Transport Proteins help move substances In and Out of the cell

Membrane Game