Housekeeping

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Housekeeping

• EXAM
• The talks
• Bioterrorism 10/29
• Genomes 11/21
• Seminar-David Schindler (p.1090 of your book)
• David Schindler
• 400 pm The Effects of Lost Biodiversity on the
  Functioning of Species-Poor Ecosystems, Viking
  Theater
• 730 pm The Cumulative Effects of Climate Change
  and Other Human Activity on Freshwater
  Communities, Sc 280
• Tuesday
• Library assignment cancelled
• Finish up todays lecture, Ch8

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Discussed What if Fat doesnt make you fat? by
Gary TaubesNew York Times, July 7, 2002
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Who are we?

• We need structure
• We need to reproduce
• We need to grow and develop
• We need energy
• We need to interact with the environment

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What are we composed of?We have structure
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What are we composed of?
Atoms
Compounds
Macromolecules
Cell
Nucleus DNA Ribosomes Endomembrane Organelles
Elements Covalent bonds
Proteins Lipids Carbohydrates Nucleic acid
Carbon compounds Functional groups
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Howd we figure this all out??
Howd we see structure??
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The MICROSCOPE
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The use of a microscope

• Magnification make it bigger
• Resolution the distance between two points
• Contrast enhance the details

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Contrast
brightfield
Phase-contrast
Brightfield stained
Nomarski
Fluorescence
Confocal
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SIZE is important!
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Types of microscopes

• Light microscope
• Electron microscope
• Transmission electron microscope
• Scanning electron microscope

Advantages/Disadvantages?
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Howd we figure this all out??
What are these structures functions??
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Cell fractionation

• Homogenization
• Centrifuge/Ultracentrifuge

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What have we found out?
Revelation of structure and function!
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Compare the cell to a grocery store
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Do the bare minimum!

• Get only what it needs
• Why waste energy?
• Only have so much
• Why waste space?
• Only have so much
• Maintenance

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Grocery store space
Cell size?
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The store
Cells are small!

• Have an optimal size
• Cells requirements
• Stuff (Volume)
• Environment (Surface area)

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What are the components of the grocery
store?The components of the cell
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The actual grocery store building

• Need structure
• Need protection
• Need to get in/out
• Needs to be efficient

Cell/plasma membrane
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The cell membrane
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The cell membrane proteins/carbs, etc..
plasma membrane
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Outside the membrane Extracellular matrix
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Grocery store isnt empty!
Cytosol
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Managers office

• Foundation/center of the store

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Managers office
DNA proteins
Chromosomes
Chromatin
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Need to make the products
Ribosomes
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Production team
Ribosomes

• rRNA and proteins
• 2 subunits
• Make proteins

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Production team
Free ribosomes (Cytoplasm), make protein for
cytosol
Membrane-bound ribosomes (Endoplasmic reticulum
or nuclear envelope), make protein destined for
cell membrane, organelles (needs packaged), or
leaving the cell
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Different production team for different products
Other products besides proteins
Smooth endoplasmic reticulum
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Production Team
Smooth endoplasmic reticulum (ER)

• Makes lipids
• Metabolism of carbohydrates
• Detox of drugs, poisons
• Other functions

Enzymes
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Production team
rough endoplasmic reticulum (ER)

• Have ribosomes
• Secretory proteins
• Protein modifications
• Glycoproteins
• Transport vesicles

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Production successful
Warehouse and shipping
Golgi apparatus
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Golgi apparatus
Warehouse and shipping
Cis receiving
Cisternae
Transport vesicles
Trans shipping
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Golgi apparatus

• Modification of products from the ER
  (glycoproteins)
• Storage
• Shipping and directing

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Grocery store garbage
lysosome
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Lysosome
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Lysosome
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Lysosome
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Lysosome

• Hydrolytic enzymes
• Low pH
• Recycle cellular products (autophagy)
• Cell destruction

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Vacuoles

• Food vacuoles
• Contractile vacuoles
• Protists
• Central vacuole (Plants)
• Cell growth
• Storage
• reserves
• Pigments
• Poisonous products

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The Grocery store
Managers office
Production teams
Waste management
Warehouse and shipping
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Grocery store
Building has structure
cytoskeleton
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Cytoskeleton

• Structural support
• Anchor
• Cell motility
• Regulate cell function?

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Cytoskeleton What is it made of?
Microtubules

• Hollow rods of tubulin (protein)
• Grow out from centrosome
• Centrosome2 pair centrioles
• Centriole9 triplet microtubules

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Microtubule function

• Shape and support
• Separation of chromosome during replication
• Centrioles replicate before division
• Movement
• Cilia
• Flagella

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Cytoskeleton What is it made of?

• Microtubules
• Microfilaments
• Actin (protein)
• Support, bear tension
• Cell motility
• Intermediate filaments
• Keratins
• Cell shape

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The grocery store
Have to sell food!
Energy transformers
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Mitochondria

• Cellular respiration
• Contains DNA and ribosomes

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Chloroplasts

• Contain chlrophyll
• Photosynthesis

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In sum,
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All components must work together!
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Differences in cells
Prokaryotes
Eukaryotes

• Microorganisms (bacteria)
• Macromolecules
• No nucleus
• No organelles
• No cytoskeleton
• Size (1-10 ?m)

• Animals, plants, single-celled organisms
• Macromolecules
• Nucleus
• Organelles
• Cytoskeleton
• Size (10-100 ?m)