chapter 3 notes

Cell Structure

I. Looking at CellsA. Cells Under the Microscope-most cells

are too small to be seen by the naked eye.

1. Robert Hooke- first to observe and name cells by looking at slices of cork.

2. Anton van Leeuwenhoek-first to observe living cells.

3. Magnification-quality of making an image appear larger.

4. Resolution-measure of the clarity of an image.

B. Types of Microscopes1. Compound light microscope-uses two lenses

to view living cells

2. Electron microscope-very powerful; cannot view living cells.

II. Cell FeaturesA. Cell Theory

1. All living things are made of cells.

2. Cells are the basic units of structure and function of living things.

3. Cells come from existing cells.

B. Prokaryote- “pro = no” cell without a nucleus or membrane-bound organelles. The simplest cells. Ex: Bacteria (has DNA, ribosomes, cytoplasm, and cell wall)

C. Eukaryote- “eu = true” true cells with a nucleus and organelles. Ex: plant and animal cells.

D. The Cell Membrane1. Cell membranes are not rigid, they are fluid.2. Function is to control what enters and exits

the cell.Made of phospholipid bilayer that contains

proteins.

III. Cell OrganellesA. Nucleus-control center of the cell. Contains the DNA.

B. Ribosomes-where proteins are made.

C. Endoplasmic reticulum rough or smooth depending on whether it has ribosome. Transports proteins.

D. Golgi Apparatus-package proteins from the e.r.

E. Mitochondria-produces energy in the cell in the form of ATP.

Human cheek cell

Animal Cell-Draw

F. Plant Cell Structures1. Cell Wall-helps provide support and

maintain the shape of the plant cell.

2. Chloroplasts-plant cells only; where photosynthesis takes place.

3. Central vacuole-stores water and other substances.

Plant Cell-Draw

Onion skin slide