UNIT 3 - Cells

Warm Up #7: True or False…What do you think? All cells are the same size and shape – there is a “generic” cell. Molecules such as carbohydrates and proteins are made of cells. False It is possible for an organism to only consist of one cell. There are only two kinds of cells – plant and animal. True Some parts of living organisms are Not made of cells. Cells have to excrete waste. Life processes occur at the cellular level. Cells need molecules of food to carry out life functions. All cells in the body of a human are essentially the same. Cells are filled with water.

Hans Lippershey - 1570 Eyeglass maker who inventory of the telescope.

Galileo Galilei – 1600’s Improved the lenses of a telescope which would later be used to magnify objects in a microscope.

Robert Hooke - 1665 Invented the first microscope and first to observe and name small units that make up organisms. Hooke said the cells looked like the cells in a monestary.

Anton Van Leeuwenhoek - 1670 Improved microscope and procedures for observing cells He was able to clearly see living cells from plaque

Robert Brown - 1820 Discovered the nucleus in a cell and speculated its importance in cell control and function.

Matthias Schleiden - 1839 Observed plant cells under a microscope.

Theodor Schwann - 1839 Observed animal cells under a microscope. “Think Swan”

Rudolf Virchow - 1850 Develop the premise of the cell theory.

Cell Theory All organisms are made up of cells. Cells are the structural and functional units of organisms All cells come from pre-existing cells.

Introduction to Cells Cells: The basic Unit of the structure of life. There are two types of cells that compose all living things: Prokaryotic and Eukaryotic

Are all cells alike? Prokaryotic Cells are each of the following: Simplest type of cell. Includes only bacteria. Structure of a prokaryotic cell: No Nucleus No membrane bound organelles Includes: Circular chromosome (DNA) called plasmids and ribosomes.

Are all cells alike? Eukaryotic Cells are each of the following: More complex than prokaryotic cells. Includes protist cells, fungi cells, plant cells, and animal cells (i.e. – everything EXCEPT bacteria cells) Structure of a eukaryotic cell: Chromosomes contained within a nucleus. In addition to ribosomes contains membrane bound organelles.

Hierarchy of Cellular Organization All physical matter is organized in a specific way, beginning with the smallest unit, an atom.

Living

Cell Specialization Different cells have different specialized structures and functions. Specialized function of cell depends on unique environment of the cell Ex: Fresh water vs. Salt water environments The specific form (structure) of a cell allows it to perform a specific function FORM RELATES TO FUNCTION Nerve cells have branching dendrites attached to the cell body to receive messages and an axon to transmit messages

Specialized Cells in the Human Body

Written Response #1 Who first observed dead cells? Who first observed living cells? Hooke, Leeuwenhoek What are the two main types of cells? Prokaryotic and Eukaryotic How is the location of the DNA different in prokaryotic and eukaryotic cells? Floating the cytoplasm in prokaryotic cells, contained in a nucleus in eukaryotic cells. What is cell specialization? Cells have different specialized structures and function. In cells, form relates to ______________. Function

Compound Microscopes The improvement of the microscope has contributed significantly to these discoveries: Cells were first observed in the 1600’s when the compound microscope was invented. Capable of magnifying 1000 times.

Light Microscopes Light Microscope: Uses light and lenses to magnify an image. Steps for use: Focus on an image with the lowest objective, sharpen with the fine focus, increase magnification.

Scanning Electron Microscope (SEM) SEM Microscope: Scanning Electron Microscope. Steps for use: Uses electron beams to detect molecular composition of a specimen. Benefits: Capable of magnifying with much more detail. Total Magnification: Magnification of eyepiece x objective.

Transmission Electron Microscope (TEM) Designed to look at structures inside a cell. Capable of greatest magnification.

Limitations of microscopes Magnification is limited by the strength of the lens. Calculating magnification: Ocular lens X Objective Lens = Total Magnification As magnification increases resolution (sharpness) decreases.

Written Response #2 Why must specimens be thin for a compound light microscope? Which microscope provides the highest possible magnification? If the ocular lens is 10x and the objective lens is 10x then the total magnification is? As magnification increases resolution _________________.

Microscope Lab 1 Complete Lab and Submit.

Microscope Lab 2 Complete Lab and Submit.