Ch. 4 Section 1 Ch. 4 Section 1 ObjectivesObjectivesNameName the scientists who first observed living and the scientists who first observed living and nonliving cells.nonliving cells.

SummarizeSummarize the research that led to the the research that led to the development of the cell theory.development of the cell theory.

StateState the three principles of the cell theory. the three principles of the cell theory.

ExplainExplain why the cell is considered to be the basic why the cell is considered to be the basic unit of life.unit of life.

The Discovery of CellsThe Discovery of Cells

All living things are made up of one or All living things are made up of one or more cells.more cells.

A A cellcell is the smallest unit that can carry on is the smallest unit that can carry on all of the processes of life.all of the processes of life.

Section 1 The History of Cell Biology

Ch. 4 Cell Discovery cont.Ch. 4 Cell Discovery cont.

HookeHooke Robert Hooke discovered cells in slices of Robert Hooke discovered cells in slices of

cork.cork.

LeeuwenhoekLeeuwenhoek Anton van Leeuwenhoek was the first to Anton van Leeuwenhoek was the first to

observe living cells in microorganisms. observe living cells in microorganisms.

Cell Theory DevelopmentCell Theory Development(Schleiden, Schwann, and Virchow)(Schleiden, Schwann, and Virchow)

1838 Matt Schleiden: All Plants 1838 Matt Schleiden: All Plants are composed of cellsare composed of cells

1839 Theodor Schwann: All 1839 Theodor Schwann: All Animals are composed of cellsAnimals are composed of cells

1847 Rudolf Virchow: Cells come 1847 Rudolf Virchow: Cells come only from other cellsonly from other cells

Cell TheoryCell Theory

The The cell theorycell theory states that all living states that all living organisms are made of one or more organisms are made of one or more cells, cells are the basic units of structure cells, cells are the basic units of structure and function, and cells come only from and function, and cells come only from pre-existing cells.pre-existing cells.

Cell Theory cont.Cell Theory cont.

Cellular Basis of LifeCellular Basis of Life All living things are made of organized parts, All living things are made of organized parts,

obtain energy from their surroundings, obtain energy from their surroundings, perform chemical reactions, change with perform chemical reactions, change with time, respond to their environment, and time, respond to their environment, and reproduce.reproduce.

The Cell TheoryThe Cell Theory

#1 All living things are made of 1 or #1 All living things are made of 1 or more cellsmore cells

#2 Cells are the basic units of structure #2 Cells are the basic units of structure and function of an organism and function of an organism

#3 Cells come only from the #3 Cells come only from the reproduction of existing cells (new cells reproduction of existing cells (new cells come only from other cells)come only from other cells)

Section 2 Introduction to Section 2 Introduction to CellsCells

Explain Explain the relationship between cell shape and the relationship between cell shape and cell function.cell function.

IdentifyIdentify the factor that limits cell size. the factor that limits cell size.

DescribeDescribe the three basic parts of a cell. the three basic parts of a cell.

CompareCompare prokaryotic cells and eukaryotic cells. prokaryotic cells and eukaryotic cells.

AnalyzeAnalyze the relationship among cells, tissues, the relationship among cells, tissues, organs, organ systems, and organisms.organs, organ systems, and organisms.

Objectives:

Cell DiversityCell Diversity Cell ShapeCell Shape

A cell’s shape reflects A cell’s shape reflects its function.its function.

Cell Diversity cont.Cell Diversity cont.

Cell SizeCell Size Cell size is limited by Cell size is limited by

a cell’s surface area–a cell’s surface area–to-volume ratio.to-volume ratio.

Surface AreaSurface Area per per VolumeVolume RatioRatio

4 sides:1 box

4/1=4 sides per square 12 sides:9 boxes

12/9=1.333 sides per square

What is the surface area What is the surface area to volume ratio?to volume ratio?

Cell PartsCell Parts The three basic parts of a cell are the The three basic parts of a cell are the

plasma membrane, the cytoplasm, and the plasma membrane, the cytoplasm, and the nucleus.nucleus.

Cell Parts cont.Cell Parts cont.

Plasma MembranePlasma Membrane The cell’s outer boundary, called the The cell’s outer boundary, called the plasma plasma

membranemembrane (or the cell membrane), covers a (or the cell membrane), covers a cell’s surface and acts as a barrier between cell’s surface and acts as a barrier between the inside and the outside of a cell.the inside and the outside of a cell.

Cell Parts cont.Cell Parts cont.

CytoplasmCytoplasm The region of the cell that is within the The region of the cell that is within the

plasma membrane and that includes the plasma membrane and that includes the fluid, the cytoskeleton, and all of the fluid, the cytoskeleton, and all of the organelles except the nucleus is called the organelles except the nucleus is called the cytoplasmcytoplasm. .

Cell Parts cont.Cell Parts cont.

NucleusNucleus The The nucleusnucleus is a membrane-bound is a membrane-bound

organelle that contains a cell’s DNA. organelle that contains a cell’s DNA.

2 Basic Types of Cells2 Basic Types of Cells ProkaryotesProkaryotes

Prokaryote cellsProkaryote cells lack a nucleus and lack a nucleus and membrane-bound organelles.membrane-bound organelles.

2 Types of Cells cont.2 Types of Cells cont. EukaryotesEukaryotes

Eukaryote Eukaryote cellscells have have a nucleus a nucleus and and membrane-membrane-bound bound organelles.organelles.