A View of the Cell Chapter 7 Background

A View of the Cell Chapter 7

Background Info Cells = smallest unit that can carry life processes 1665 Robert Hooke first observed cells using light microscope Leeuwehoek first observed living cells with a better crafted lens

Think, Pair, Share 1. What 2 parts of the microscope magnify? 2. What 2 parts of the microscope focus? 3. If the objective is 10 X and the ocular is 10 X, what is the magnification?

Light Microscopes (p. 171) Compound Light Microscope = uses lenses to magnify objects, can magnify up to 1500 times

Electron Microscopes (p. 172) Electron Microscope = uses a beam of electrons instead of light to magnify structures, can magnify up to 500, 000 times

SEM = scanning electron microscope, scans the surface of cell TEM = transmission electron microscope, allows view within cell

Think, Pair, Share 4. A scientific theory is based on ? 5. A scientific law is based on ? 6. True or False – Scientific Theories become Scientific Laws.

Cell Theory (p. 172) 1. All living organisms are comprised of one or more cells.

2. Cells are the basic units of structure, function, and organization in an organism.

3. Cells come only from preexisting cells.

Think, Pair, Share 7. List characteristics that scientists would use to classify cells.

Types of Cells (p. 173) 1. Prokaryotes = bacteria cells No true nucleus, not membrane bound Nucleoid = unbound ball of DNA 2 Domains – Archaea = similar to 1 st forms of life on earth – Eubacteria = more closely related to eukaryotic cells

2. Eukaryotes = plant & animal cells with a true membrane bound nucleus Organisms made up of one or more cells Membrane bound organelles Organelles = well-defined structures, perform specific functions, usually surrounded by membrane Larger than prokaryotic cells

Eukaryotic Cell

Basic Parts of A Cell Plasma Membrane = cell membrane, barrier between outside & inside. “Fluid Mosaic Model”

Cytoplasm = fluid (cytosol) and organelles inside the cell Nucleus = membrane bound organelle containing DNA

Compare and Contrast Eukaryotic and Prokaryotic Cells

Plant vs. Animal Cell