LECTURE PRESENTATIONSFor CAMPBELL BIOLOGY, NINTH EDITION

Jane B. Reece, Lisa A. Urry, Michael L. Cain, Steven A. Wasserman, Peter V. Minorsky, Robert B. Jackson

© 2011 Pearson Education, Inc.

Lectures byErin Barley

Kathleen Fitzpatrick

A Tour of the Cell

Chapter 6

The endomembrane system regulates protein traffic and performs metabolic functions in the cell

• Components of the endomembrane system– Nuclear envelope– Endoplasmic reticulum– Golgi apparatus– Lysosomes– Vacuoles– Plasma membrane

• These components are either continuous or connected via transfer by vesicles

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Figure 6.11 Smooth ER

Rough ER

ER lumen

CisternaeRibosomes

Smooth ERTransport vesicle

Transitional ER

Rough ER 200 nm

Nuclearenvelope

Figure 6.12

cis face(“receiving” side ofGolgi apparatus)

trans face(“shipping” side ofGolgi apparatus)

0.1 m

TEM of Golgi apparatus

Cisternae

Figure 6.15-3

Smooth ER

Nucleus

Rough ER

Plasmamembrane

cis Golgi

trans Golgi

A pancreatic beta cell produces and secrete insulin (a protein hormone).

Trace the pathway of production and export of this protein from the nucleus to the blood stream.

Describe what happens at each stop along its way.

Brefeldin A is an antibiotic produced by fungal organisms.

It interferes with transport from the ER to the Golgi apparatus (by blocking receiving end of the Golgi), leading to proteins accumulating inside the ER.

What are the immediate and long-term consequences of this antibiotic on cell structure and function?

Concept 6.5: Mitochondria and chloroplasts change energy from one form to another

• Mitochondria are the sites of cellular respiration

• Chloroplasts are the sites of photosynthesis

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• Mitochondria and chloroplasts have similarities with bacteria

– Enveloped by a double membrane– Contain free ribosomes and circular DNA

molecules– Grow and reproduce somewhat

independently in cells

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The Evolutionary Origins of Mitochondria and Chloroplasts

Figure 6.17

Intermembrane space

Outermembrane

DNA

Innermembrane

Cristae

Matrix

Freeribosomesin themitochondrialmatrix

(a) Diagram and TEM of mitochondrion (b) Network of mitochondria in a protistcell (LM)

0.1 m

MitochondrialDNA

Nuclear DNA

Mitochondria

10 m

Figure 6.18

RibosomesStroma

Inner and outermembranes

Granum

1 mIntermembrane spaceThylakoid

(a) Diagram and TEM of chloroplast (b) Chloroplasts in an algal cell

Chloroplasts(red)

50 m

DNA

• The Endosymbiont theory – An early ancestor of eukaryotic cells engulfed

a nonphotosynthetic prokaryotic cell, which formed an endosymbiont relationship with its host

– The host cell and endosymbiont merged into a single organism, a eukaryotic cell with a mitochondrion

– At least one of these cells may have taken up a photosynthetic prokaryote, becoming the ancestor of cells that contain chloroplasts

© 2011 Pearson Education, Inc.

NucleusEndoplasmicreticulum

Nuclear envelope

Ancestor ofeukaryotic cells(host cell)

Engulfing of oxygen-using nonphotosyntheticprokaryote, whichbecomes a mitochondrion

Mitochondrion

Nonphotosyntheticeukaryote

Mitochondrion

At leastone cell

Photosynthetic eukaryote

Engulfing ofphotosyntheticprokaryote

Chloroplast

Figure 6.16

Figure 6.UN01a

Nucleus

(ER)

Figure 6.UN01c

carbohydrates lipids proteins nucleic acids

Always contain P

Generally contain no P*

Always contain N

Generally contain no N

Frequently contain S

Generally contain no S

Functional group

Polar or Nonpolar?

Hydrophobic or Hydrophilic

Found in all proteins

Found in many proteins

Found in many lipids

—OH

—CH2

—COOH

—NH2

—SH

—PO4

Compare and contrast the two molecules below using the following criteria :A.the arrangement of carbon, hydrogen, and oxygen atomsB.the types of carbon, hydrogen, and oxygen atomsC.the number of carbon, hydrogen, and oxygen atomsD. the number of covalent bondsE. Functional role in cell

The functional group of the amino acid threonine is -OH. The functional group of the amino acid valine is methyl. Where would you expect to find these amino acids in globular protein in aqueous solution? Draw a picture