Do Now What are cells? Why do we need them? List different types of cells that you know of…

Objective Describe how cells were discovered and named. Identify the scientists that discovered and observed cells. List the 3 parts of the cell theory.

LETS CELLEBRATE! Chapter 1

What are Cells? a) Basic structural and functional unit of all living organisms! b) They come in all shapes and sizes Lets take a look…

How were they discovered? a) The light microscope led to the discovery of cells.

Who discovered cells? i.Observed dead cork cells. ii.Said boxes looked like tiny rooms or cells, that is where they get their name. iii. Used a microscope at 30x magnification

Who discovered cells? i.Observed pond water. ii.1 st to observe living cells. iii. Used a microscope at 300x magnification But WHERE do they come from????

Hmmmm…

What happens when you leave meat out?

Fransisco Redi Experiment He placed meat in both an open container, and a closed container to see what happened…

Redi’s Conclusion… -Maggots come from FLIES, not meat. -Life must come from life, not spontaneous generation right? -Nobody believed him!

Where do cells come from? i. Discovered that cells must come from other cells. ii. He disproved the theory of “spontaneous generation”- theory that life can just appear out of nowhere.

Pasteur’s Experiment

Control group- Experimental group-

Pasteur’s Results flask that was exposed to the air contained bacteria in it from the air. Flask that wasn’t exposed did not contain anything. The cells must come from living things in the air!!

Pasteurization *Pasteur came up with the idea of Pasteurization after discovering bacteria could contaminate milk from the air. This process kills the bacteria so that it does not harm us!

Cell Theory! Cells come only from other living cells. Every living thing is made of 1 or more cells. Cells carry out the functions needed to support life.

Do Now When you drew your slides in lab, were they in 3D? What would be the benefit of seeing something in 3D? Could you see through the specimens that you were looking at? Why might this be beneficial?

Objective Compare and contrast a scanning electron microscope vs. a transmission electron microscope. Describe prokaryotic and eukaryotic cells.

Section MICROSCOPES How small are cells? –We use micrometers (μm )= 1 millionth of a meter! –Range from 1 μm to 1000 μm

Types of Microscopes A)Compound Light Microscrope (LM) B)Scanning electron microscope (SEM) C)Transmission electron microscope (TEM)

Compound Light Microscope i. Uses light ii. Thin specimen iii. Total magnification = 40x-100x iv. Used to see cells, but not organelles inside

Scanning Electron Microscope (SEM) i. Uses electrons that bounce off the specimen ii. 3-D image, must be dead  iii. Specimen is coated in metal iv. Total magnificatio n= 100,000x v. See details of OUTSIDE of cell, cell membrane and cilia.

Transmission Electron Microscope (TEM) i. Uses electrons to deflect through specimen ii. Thin specimen iii. Total magnificat ion= 300,000x iv. Allows us to see organelles INSIDE cell.

Prokaryotes vs. Eukaryotes What do you notice that is different between these 2 cells?

Prokaryotic Cells i. Have circular DNA ii. NO nucleus iii. Doesn’t have membran e-bound organelles iv. Most unicellula r organisms are prokaryot es Example: Bacteria

Eukaryotic Cells i. Have linear DNA that is in a double helix shape. ii. Has a nucleus. iii. Have membrane- bound organelles. iv. Mostly multicellular although there are some unicellular eukaryotes Multicellular Eukaryote Unicellular Eukaryote

Where did these cells come from? Scientist: Lynn Margulis Theory: organelles in eukaryotic cells were once prokaryotes that were engulfed!

Theory= EVIDENCE!! i. Mitochondria have circular DNA like bacteria ii. Replicates (reproduces) like bacteria separate from the host cell iii. Mitochondria make their own proteins iv. Mitochondria have two membranes (one from the host cell and one from their own cell membrane)