Advanced Cell Biology. Lecture 2

Advanced Cell Biology. Lecture 2

Alexey Shipunov

Minot State University

January 13, 2012

Advanced Cell Biology. Lecture 2

Outline

Questions and answers

Introduction to cellsMicroscopyProkaryotic and eukaryotic cells

Model organisms

Advanced Cell Biology. Lecture 2

Outline

Questions and answers

Introduction to cellsMicroscopyProkaryotic and eukaryotic cells

Model organisms

Advanced Cell Biology. Lecture 2

Outline

Questions and answers

Introduction to cellsMicroscopyProkaryotic and eukaryotic cells

Model organisms

Advanced Cell Biology. Lecture 2

Questions and answers

Previous final question: the answer

What is that?

I Synapse—the contact between two neural cells (neurons)

Advanced Cell Biology. Lecture 2

Questions and answers

Previous final question: the answer

What is that?

I Synapse—the contact between two neural cells (neurons)

Advanced Cell Biology. Lecture 2

Introduction to cells

Microscopy

Introduction to cellsMicroscopy

Advanced Cell Biology. Lecture 2

Introduction to cells

Microscopy

MiscroscopesLight microscopy based on visible light rays and glass optics,

most common are “transparency” microscopeswhere light goes through object (stained withspecific dyes or not stained); there are also“reflection” (dissectiscopes) and fluorescentmicroscopes

Transmission electron microscopy (TEM) based of the flow ofelectrons through specially prepared (usuallystained with osmium, Os), extremely thin object;allows to see the internal organization of cells andorganelles

Scanning electron microscopy (SEM) based on the electronicreflection from the surface covered with metals(typically, gold, Au) and provides an image of thesurface of cells and organisms

Advanced Cell Biology. Lecture 2

Introduction to cells

Microscopy

Light microscopy

Advanced Cell Biology. Lecture 2

Introduction to cells

Microscopy

Electron microscopy

Advanced Cell Biology. Lecture 2

Introduction to cells

Prokaryotic and eukaryotic cells

Introduction to cellsProkaryotic and eukaryotic cells

Advanced Cell Biology. Lecture 2

Introduction to cells

Prokaryotic and eukaryotic cells

Organelles in prokaryotic and eukaryotic cells

I Prokaryotic: [cell wall], plasma membrane, cytosol,[vacuoles], [prokaryotic flagella], nucleoid, [tylacoids]

I Eukaryotic: [cell wall], plasma membrane, cytosol, nucleus,mitochondria, [chloroplasts], endoplasmatic reticulum,[Goldgi apparatus], vesicles (vacuoles, lysosomes etc.),cytoskeleton, [eukaryotic flagella]

Advanced Cell Biology. Lecture 2

Introduction to cells

Prokaryotic and eukaryotic cells

Comparison of prokaryotic and eukaryotic cells

Please copy drawings from a board

Advanced Cell Biology. Lecture 2

Introduction to cells

Prokaryotic and eukaryotic cells

Comparative biology of prokaryotic and eukaryoticcells

I Eukaryotic cells are 10–100 times bigger than prokaryoticI Eukaryotes have cell motility and capable to endo- and

exocytosisI Prokaryotes have combined RNA and protein synthesisI Prokaryotes are more diverse chemically, whereas

eukaryotes are more diverse morphologically

Advanced Cell Biology. Lecture 2

Introduction to cells

Prokaryotic and eukaryotic cells

PVC bacteria have nucleus-like structures

[From Lee et al., 2010]

Advanced Cell Biology. Lecture 2

Introduction to cells

Prokaryotic and eukaryotic cells

Symbiotic origin of eukaryotic cell

I Double membrane and own DNA are unique features ofmitochondria and chloroplasts

I Originally, endosymbiosis was an idea of Russianscientists (Konstantin Merezhkovsky and BorisKozo-Poljansky), it was revived in 60s by Lynn Margulis(UMass Amherst).

I The host cell was probably predatory archaeon (belongs toArchaea domain) or PVC bacteria (hypothesis of Forterre,2010)

I Mitochondria were first symbionts, probably proteobacteriaI Chloroplasts appeared later, from cyanobacteria

Advanced Cell Biology. Lecture 2

Model organisms

Diversity of life and model organisms

I Escherichia coli, or E. coli: proteobacteriaI Saccharomyces cerevisae: fungal protistI Arabidopsis thaliana: flowering plant from cabbage familyI Drosophila melanogaster: fly (Diptera) insectI Caenorabditis elegans: round worm (Nematoda)I Mus musculus: common mouse (rodent mammal)

Advanced Cell Biology. Lecture 2

Model organisms

Less common model organisms

I Gallus gallus: chicken (Aves, birds)I Danio rerio: zebrafish (Pisces)I Strongylocentrotus purpuratus: purple sea urchin

(Echinodermata)I Hydra vulgaris: freshwater hydra (Cnidaria)I Trichoplax adhaerens: basal animal (Placozoa)I Neurospora crassa: orange bread mold (fungal protist)I and many others

Advanced Cell Biology. Lecture 2

Model organisms

Zebrafish, Danio rerio

Advanced Cell Biology. Lecture 2

Model organisms

Sea urchin, Strongylocentrotus purpuratus

Advanced Cell Biology. Lecture 2

Model organisms

Hydra, Hydra vulgaris

Advanced Cell Biology. Lecture 2

Model organisms

Trichoplax adhaerens

Advanced Cell Biology. Lecture 2

Model organisms

Orange bread mold, Neurospora crassa underfluorescent microscope

Advanced Cell Biology. Lecture 2

Model organisms

Final question (2 points)

Which organelle is present in most prokaryoticcells and absent in all eukaryotic?

Advanced Cell Biology. Lecture 2

Model organisms

Final question (2 points)

Which organelle is present in most prokaryoticcells and absent in all eukaryotic?

Advanced Cell Biology. Lecture 2

Model organisms

Summary

I Electron microscope can only work with dead cellsI Eukaryotic cells are “cells of second level” where part of

organelles (mitochondria, chloroplasts) originated fromdifferent prokaryotic cells.

Advanced Cell Biology. Lecture 2

Model organisms

For Further Reading

A. Shipunov.Advanced Cell Biology [Electronic resource].2011—onwards.Mode of access: http://ashipunov.info/shipunov/school/biol_250

B. Alberts et al.Essential Cell Biology. 3rd edition.Garland Science, 2009.Chapter 1: Cells under the microscope; The prokaryoticcell; The eukaryotic cell.