THE CELL Chapter 1
Dec 27, 2015
Chapter Objectives
• Differentiate unicellular and multicellular organisms.
• List the characteristics of life/living things.
• Identify the scientists that observed and discovered cells.
• List the 3 parts of the cell theory.
• Compare light, SEM, and TEM microscopes.
• Compare prokaryotic vs. eukaryotic cells AND plant vs. animal cells.
• Explain the term specialization and compare to our bodies.
DO NOW …
• What are cells?
• Name different types of cells you know of...
• What is a difference between living and non-living things?
What is a cell?
• Basic structural and functional unit of all living organisms!
• They come in different shapes + sizes
Who discovered the cell?
ROBERT HOOKE
• Observed dead cork cells
• Said boxes looked like tiny rooms or jail “cells”.
• Used a microscope at 30x magnification
Who else discovered the cell?
ANTON VAN LEEUWENHOEK
• Observed pond water
• 1st to observe “living” cells
• Used a microscope at 300x magnification
Fransisco Redi Experiment
• Placed meat in both an open container and a closed container to see what happened.
Redi’s Conclusion
• Maggots come from flies, NOT the meat!
• Life must come from life, which proved that spontaneous generation is not real!
• People still did not believe him but he was right.
Louis Pasteur Conclusions
• Discovered that cells MUST come from other cells
• Disproved “Spontaneous Generation” and said life cannot just appear out of no where.
• Helped verify Redi’s research!
DO NOW
1. Give an example of a multicellular organism and unicellular organism.
2. What type of cells did Robert Hooke observe?
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!
• Used in milk, cheese, yogurt, etc.
• Cell Theory = • Every living thing is made of one or
more cells• Cells carry out the functions needed
to support life• Cells come only from other living
cells
Characteristics of Life
1. Organization
2. The ability to develop and grow
3. The ability to respond to the environment
4. The ability to reproduce
Section 1.2 - Microscopes
How small are cells?
• Unit used = micrometer (um)
One millionth of a meter
• Most cells range from 1 um to 1000
um.
Light Microscope
• Uses thin light
• Looks at thin specimen
• Total Magnification = 40x-1000x
• Use to see cells, but not detailed organelles
SEM vs. TEM
SEM• “Scanning electron
microscope”
• Beams of electrons bounce of the surface of the coated cell.
• Images appear 3D
• Total Magnification = 100,000x
• Must be dead ☹. Specimen coated in metal
TEM• “Transmission electron
microscope”
• Electrons pass through the think section.
• Images appear 2D
• Total Magnification = 300,000x
• Allows us to see organelles inside the cell
Prokaryotic Cells
• Have circular DNA
• NO nucleus
• Does not have membrane bound organelles ex: snow globe
• Most unicellular organisms are prokaryotes
Example: Bacteria
Eukaryotic Cells
• Have linear DNA – double helix shape
• Has nucleus
• Have membrane bound organelles
• Most multicellular organisms are eukaryotic cells. Some are unicellular though.
Example: You!
Section 1.3 – cell functions
• 3 domains of life:• Eukarya – Have a nucleus. Plants, animals,
and fungi.• Bacteria – prokaryotics. • Archaea – “ancient”. Genetically different
from bacteria.
Specialization
•Specific cells perform specific functions.
Ex: Blood cells can only be blood cells. Muscle cells cannot be turned into blood cells.
Tissue and organs
• Tissue – group of similar cells that are organized to do a specific job.
• Organ – different tissues working together to perform a particular function.
Stem Cells to determine specialization
• https://www.youtube.com/watch?v=evH0I7Coc54
DNA
• Rosalind Franklin – used x-rays to produce images of DNA
• Watson and Crick – put together a 3D model of DNA and present it to the world in 1953