Date: October 25, 2016 Aim #20: How do enzymes control the rate of chemical reactions? HW: Study! Textbook HW due day of test! (Tomorrow!) Do Now: Write down one question you still have about this unit or one topic you would like to review.

Aim #24: How was the cell theory developed? Date: October 28, 2016 Aim #24: How was the cell theory developed? HW: “Dog Ate My Homework” article review Quarterly Exam Thursday 11/3 (period 1), Friday 11/4 (period 5) Do Now: Complete the following statements. All living things are made up of one or more _____________. ___________ is the increase in cell size or cell number. ___________ organisms are made up of ONE cell (i.e. bacteria) ___________ organisms are made up of MANY cells (i.e. humans)

The Wacky History of the Cell Theory http://ed.ted.com/lessons/the-wacky-history-of-cell-theory

How was the cell theory developed? Aim #24: How was the cell theory developed?

1) Unicellular vs. Multicellular Multicellular- made up of MORE THAN ONE cell Unicellular- made up of ONE cell

Organization of Living Things… Cells  Tissues  Organs  Organ Systems  Organisms

2) What are the four characteristics of life? Cells: Basic units of structure & function Metabolism: Chemical reactions in cells Homeostasis: Internal Balance Reproduction: Produce offspring

What instrument was vital for scientists to discover and learn more about cells? Visible light passes through an object & glass lenses then enlarge the image & project it into the human eye. This instrument allows scientists to see larger parts of a cell (cell membrane, nucleus, chromosomes, etc…) A light microscope can magnify objects up to 1000 times. Light Microscope

A Brief History of Cells https://app.discoveryeducation.com/learn/videos/0F349698-ABEF-46B6-BC7C- 5E2162505768?hasLocalHost=false

Anton Van Leeuwenhoek 1600s Developed simple light microscopes that allowed him to examine tiny living organisms he called “animacules”

Robert Hooke 1665 What is this? Cork Cells First compound microscope First person to use the word “cell”

Matthias Schleiden 1838 ALL PLANTS ARE MADE UP OF CELLS!!

Theodor Schwann 1838 ALL ANIMALS ARE MADE UP OF CELLS!!

Rudolf Virchow 1858 CELLS COME FROM PRE-EXISTING CELLS!

6) What are the three parts of the cell theory? All living things are made of cells Cells are the basic unit of structure and function (metabolism) New cells come from pre-existing cells

7) What are some exceptions to the cell theory? Viruses. Are viruses living? contain genetic material and protein but are smaller than cells and cannot reproduce outside of a cell. The first cell. Where did the first cell come from? could not have arisen from a previously existing cell. Mitochondrion and Chloroplasts contain their own genetic information and can replicate on their own inside of cells.

Viruses They are not made up of cells, but are they living?

What do you know about viruses? They can make you very sick They can be transmitted from person to person There are different types of viruses

8) How big is a virus? Too small to be seen with a light microscope. They are microscopic and smaller than cells!!

9) What instrument allows scientists to see viruses? Electron Microscope!

10) What are four features of an electron microscope? Used to view extremely small structures inside cells & viruses Utilizes an electron beam instead of a light beam Can magnify up to a million times Subject must be dead and dry

11) So… is a virus classified as a living thing? NO! A virus is nonliving Viruses cannot reproduce, they must invade a host cell in order to replicate!

Introduction to Viruses Video https://app.discoveryeducation.com/learn/videos/2D78711C- 48C2-454B-91B0-6F95863F04D0?hasLocalHost=false

13) Let’s compare and contrast viruses and bacteria Bigger than a virus Smaller than bacteria It has complex structure Virus has spiky outer skin Both cause disease Rigid cell wall Viruses do not have enough DNA blueprints to reproduce. Must invade a host cell. Bacteria has lots of DNA blueprints to reproduce. Both contain DNA and enzymes First discovered by Anton Van Leeuwenhoek in 1670 Discovered by Martinus Benjerunck in 1898

NPR: Flu Attack! How a virus invades your body https://www.youtube.com/watch?v=Rpj0emEGShQ