1. Cell Structure and Function
Unit 4

2. What is a cell? Cells are the basic units of life.
Muscle Cells Nerve Cells

3. In Robert Hooke examines a slice of cork under a compound microscope and sees empty chambers he calls “cells”. Next Anthony van Leeuwenhoek uses a single lens microscope to view pond water and sees tiny living organisms in the water!

4. In 1838 Mattias Jakob Schlieden concludes that all plants are made of cells. One year later in 1839 Theodor Schwann concludes that all animals are made of cells.

5. Rudolf Virchow
New cells come from existing cells

6. These discoveries lead to…
Cell theory which states-
All living things are composed of cells
Cells are the basic units of structure and function in living things
New cells are produced from existing cells

7. Modern Cell Exploration
Today scientists still study cells but they have better tools to do so.
Flourescent Labels- enable scientists to track molecules throughout the cell

8. From cell to organism
A cell is the basic unit of life, from which larger structures such as tissue and organs are made.
All living things are made up of cells. The appearance of each living thing is the result of the types of cell that it is made up of and how these cells are organized.
Photo credit (left): © 2009 Jupiterimages Corporation
Photo credit (right): © 2009 Jupiterimages Corporation

9. Types of Cells
Prokaryotic (Prokaryote)
Eukaryotic (Eukaryote)

10. Similarities All cells have 2 things in common:
They are surrounded by a cell (plasma) membrane
They contain DNA, the molecule that carries biological information, at some point in their life
Both

11. Differences Prokaryotes Eukaryotes DNA not contained in nucleus
Karyon means kernal in Greek
Pro means before, therefore these cells evolved before nuclei were developed
Generally less complicated
Example: bacteria
Eukaryotes
DNA contained in a nucleus
Karyon means kernal in Greek
Eu means true suggesting that these cells do have nuclei
Generally more complicated
Examples: plants, animals, fungi and protists

12. Specialized cells
Most plants and animals are multicellular. The human body is made up of around 200 different types of cells, all working together.
Most cells are specialized, meaning that each type of cell has a specific structure and function.
All cells with a nucleus contain the same genes, but different cells activate different genes so they only produce the proteins they need.
Photo credit: © 2007 Jupiterimages Corporation
Cross section of the leaf from a Dianthus (carnation) plant. Image shows epidermis, spongy and palisade cells.
Teacher notes
Red blood cells are an example of a type of cell which has no nucleus. Gametes (such as egg cells and sperm cells) only have half a full set of genes.
However, all cells have certain common features and structures called organelles.

13. Organelles are structures within cells which contribute to the overall function of the cell. Organelle means “little organ”
Nucleus
Cytoplasm