Chapter 8 n A Tour of the Cell

How can we see cells? n Light microscope – Uses light and lenses to magnify n Electron microscope – Uses beam of electrons – Gives a 3-D picture n Not a flashcard.

Electron vs. Light What can you see without a microscope? n Not a flashcard.

Here are some pictures of cells View the size of cells n Not a flashcard.

Cell Types Bone Cell Muscle Cell Nerve Cell Cartilage Cell Blood Cell Small Intestine Cell n Not a flashcard.

Discovery of the Cell n Made possible by the development of the microscope n Robert Hooke first used a microscope in 1665 n Examined a thin slice of cork n Found similar formations, “a great many little boxes,” when looking at stems of trees, carrots, and ferns n Cells – named after the small rooms in which monks lived

Cork cells n Not a flashcard.

Cell Theory The 3 Parts to the Cell Theory:  All living things are composed of one or more cells  Cells are the basic units of life  All cells come from pre-existing cells

There are 2 types of cells n Prokaryotic Example: bacteria n Eukaryotic Examples: plant & animal

Which is Bigger? Bacteria Cell Animal Cell Plant Cell Small Bigger Biggest n Not a flashcard.

Cell Type: Prokaryotic n No true nucleus n No organelles with membranes

Cell Type: Eukaryotic n Has at least 1 true nucleus n Has organelles with membranes

Prokaryotes vs. Eukaryotes

Why aren’t cells large? n As cell size, the surface area to volume ratio n Rates of chemical exchange may then be inadequate for cell size n Cell size, therefore, remains small

Cell Size n Not a flashcard.

Surface Area to Volume Ratio n Not a flashcard.

Unicellular vs. Multicellular n Unicellular Made of only ONE cell n or Multicellular Made of more than one cell

Organelles There are 16 organelles I would like you to know. n Be able to label each of them and describe their functions. n Not a flashcard.

Cell Wall n Not in animal cells n Provides: protection shape support

Cell Membrane n Made of phospholipids n Selectively permeable n Maintains homeostasis

The Cell Membrane… Controls what enters and leaves the cell n Not a flashcard.

Cytoplasm n Clear fluid that surrounds the organelles n Jelly-like

The Cytoskeleton n Fibrous network in cytoplasm n Provides support and maintains shape n Made of microtubules

Nucleus The cell’s control center Contains DNA RNA is made here

Nucleolus n Inside the nucleus n Produces ribosomes

Mitochondria n Makes energy n The more mitochondria, the more energy the cell can produce! (muscle cells)

Endoplasmic Reticulum n A folded membrane attached to the nucleus n ‘Intra-cellular highway’

Ribosomes n Small and ‘circular’ n Assembles amino acids to make proteins

Vessicles n Small packages that transport proteins from the ER to the Golgi apparatus

Golgi Apparatus n Flattened sacs n Packages proteins and lipids to leave the cell

Lysosomes n sacs of enzymes n digests particles

Vacuoles n Stores food, enzymes, and waste n Plants: only 1 LARGE

Chloroplasts n Found only in plants n Contains chlorophyll (green) n Converts sunlight to useable energy

Elodea Cells n Not a flashcard.

Centrioles n Used in cell replication; only in animal cells n Pulls chromosomes apart

Cilia vs. Flagella Locomotive appendages: n Cilia is short and hairlike (large #’s) n Flagella is longer and whiplike (small #’s)

Real Pictures of Cilia n Not a flashcard.

It’s all connected! n Not a flashcard.

Difference Between Plant & Animal Cells Plant Cells Have: n A Cell wall n Chloroplasts n Larger vacuole n No centrioles

A Plant Cell n Not a flashcard.

A Real Plant Cell n Not a flashcard.

Another Plant Cell Important Info! n Not a flashcard.

An Animal Cell n Not a flashcard.

Another Animal Cell n Not a flashcard.

Cell Cheer!

The End! See you soon!