Abiotic Origin of Cells, Cell Theory and Tour of the Cell

“Big Idea” Question: How did MASSIVE eukaryotic cells evolve from smaller ancestral prokaryotic cells?

Review: Can you identify the macromolecules?

(and what are the names of their components?)

Cell Theory and A Tour of the Cell

!  I. Review macromolecules !  II. Early Earth, the Origin of Life, and the RNA

World !  III. Cell Theory !  IV. A Tour of the Cell

The Earth’s Early Atmosphere

CH4 CH4

Stromatolites

Pioneers in Cell Biology: Louis Pasteur

How Did Life Originate?

!  Four stages: !  Abiotic synthesis of small organic molecules !  Joining these small molecules into macromolecule

polymers. !  Packaging molecules into “protobionts.” !  Origin of self-replicating molecules that make

inheritance possible.

!  What is the physical evidence?

Experiments in the Origin of Life: Stanley Miller

Stage 1. Abiotically synthesized amino acids from simple molecules found in Earth’s early atmosphere.

Stage 2: Synthesis of polymers

Simple polymers like polypeptides of amino acids may have formed by dehydration synthesis on hot sand or clay and been washed back out by tides.

Simple spheres of lipids may have been the first

cell-like structures.

Stage 3: Packaging macromolecules into “protobionts”

Stage 4: Origin of Self-replicating molecules that make inheritance

possible.

How could these four stages have resulted in life?

Simple macromolecules and genetic material that can be copied and inherited packaged into a simple lipid membrane fulfills the requirements of a simple cell.

The cell: a minimalist view

!  “Must haves:” !  A plasma membrane- delimiting boundary that

allow some passage of substances !  Genetic material- “the blueprint instructions” !  Ribosomes- The machinery that does the

building.

Pioneers in Cell Biology: Robert Hooke

Robert Hooke’s Microscope vs. the Modern Microscope

Pioneers in Cell Biology: Antony van Leeuwenhoek

Schleiden and Schwann

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1.  All organisms are made of cells. 2.  Cells are the structural and

functional units of life. 3.  All cells arise from pre-existing cells.

Tour of the Cell

Why are cells so small?

Eukaryotic Cells are MARVELS of Compartmentalization

A Plant Cell vs. Animal Cell

The Nucleus

The Endomembrane System

Endomembrane System: Endoplasmic Reticulum

The Endomembrane System: The Golgi Apparatus

!  http://www.youtube.com/watch?v=rvfvRgk0MfA

The Endomembrane System: Lysosomes

The Endomembrane System: Review Video in your disk that came with the book!

Lysosome Formation

Vacuoles

The Energy Converters: Chloroplasts

The Energy Converters: Mitochondria

The cytoskeleton!!!

1. How do you provide structural integrity to the insides of a cell?

2. How can you provide SHAPE to a cell?

3. How can you MOVE stuff around inside of a cell?

4. How can you make a cell MOBILE?

What IS the cytoskeleton?

Cytoskeleton: participates in cell division!

http://www.youtube.com/v/P7m3WfzgZdI

Actin Microfilaments enable cells to move.

http://www.youtube.com/v/WAjeMV4Lkmw

Motor proteins carry their cargo and “walk” along microtubule “tracks”

http://www.youtube.com/v/4AnPVuzF7CA

How do cilia and flagella work?

http://www.youtube.com/v/ZQpx9s58xY8

Cell surfaces PROTECT, SUPPORT, and JOIN cells

Plant Cells

Animal Cells

Four Functional Categories of Eukaryotic Organelles

1. Manufacturing 2. Breakdown

3. Energy Converting 4. Support, Movement & Communication

a.  Nucleus

b.  Ribosomes

c.  Rough ER

d.  Smooth ER

e.  Golgi Apparatus

a.  Lysosomes

b.  Peroxisomes

c.  Vacuoles

a.  Chloroplasts

b.  Mitochondria

a.  Cytoskeleton

b.  Cell Walls

c.  Extracellular Matrix

d.  Cell Junctions

Which of the following is NOT a stage that could have resulted in the abiotic origin of cellular life?

A. Abiotic synthesis of small organic molecules B.  Joining these small molecules into macromolecule

polymers. C.  Spontaneous generation of animals from inorganic

material D.  Packaging molecules into “protobionts.” E.  Origin of self-replicating molecules that make

inheritance possible.

Eukaryotic cells are distinct from prokaryotic cells in that…

A.  They contain genetic material B.  They are able to metabolize food into energy C.  They possess internalized membranes D.  They possess ribosomes

Which of the following is NOT a function of the cytoskeleton?

A.  Provide shape and support for the cell. B.  Convert energy from one form into another. C.  Make the cell mobile. D.  Participate in cell division.

Which of the following best summarizes the function of the

endomembrane system?

A.  Enables a cell to be mobile. B.  Provides support, and a means for

communication with other cells. C.  Finishes proteins for secretion or functions in

the plasma membrane or inside other organelles.

D.  The primary means by which messenger RNAs are translated into functional proteins.