lecture 2 outline (ch. 6) i.cell background ii.organelles a. nucleus, ribosomes b. endomembrane...
TRANSCRIPT
Lecture 2 Outline (Ch. 6)
I. Cell Background
II. Organelles
A. Nucleus, ribosomes
B. Endomembrane System
C. Energy Organelles
i. Mitochondria
ii. Chloroplasts
III. Cytoskeleton
IV. Extracellular Spaces
V. Lecture Concepts
Laser scanning microscopyFluorescence
Bright field
Scanning electron microscopy (SEM)
Transmission electron microscopy (TEM)
Microscopy
Stained or unstainedContrast
Prokaryotes vs. Eukaryotes
Prokaryotes:
- Archae and Bacteria
nucleoid (DNA)
ribosomes
plasma membrane
cell wall
capsule
pili
flagella
1-10μm
Eukaryotes:
- Protists, Fungi, Plants, Animals
- Several organelles
- Larger
Prokaryotes vs. Eukaryotes
10-100μm
333 μm
Eukaryotic Organelles Nucleus – genetic material
• chromosomes (DNA +
proteins)
• nucleolus -ribosome RNA made
• nuclear envelope-double bilayer
• nuclear pores• nuclear matrix
Ribosomes – protein synthesis
• Made in nucleolus
• Bound or free
• Two subunits
• Made of RNA & proteins
1. Endoplasmic reticulum (e.r.)
• Two types – rough, smooth
Rough e.r. – proteins for membrane or secretion
Smooth e.r. – detoxification, lipid and carbohydrate synthesis
Endomembrane System
– ”bleb” off in vesicles
• Extensive membrane
• Continuous with nuclear envelope
• Inside - lumen
2. Golgi apparatus• Shipping and receiving
• Flattened sacs
• Vesiscles – transport around cell
• Protein modification & direction
Endomembrane System
3. Lysosomes
• Cellular digestion
• Not in plants
• Bleb off Golgi or cell membrane
• Acidic inside – food particles (a) or old cell parts (b)
Endomembrane System
“phagocytosis” “autophagy”
Plant cell
4. Vacuoles • Storage/maintenance compartments
• Food vacuole
• Water vacuole
-contractile vacuole
• Disposal for by-products
• Central vacuoleAnimal cell
Endomembrane System
5. Plasma membrane
• Lipid bilayer – selective barrier
• Membrane-associated proteins – depend on cell type
Endomembrane System
• Present in bacteria, animals, and plants
Energy production
1.Mitochondria • energy from nutrients ATP
• Two membranes, each bilayer -inner -outer
• Intermembrane space
• Matrix
• Folds – cristae
• Own DNA!
• Own ribosomes!
2. Chloroplasts • Light to chemical energy
• Only in plants
• Outer and inner membranes - bilayer
• Internal membranes – thylakoids, stacks called grana
• Spaces – intermembrane, stroma, thylakoid
• Own DNA
• Own ribosomes
Energy production
Organelle summary
In plant cells only:
ChloroplastsCentral vacuole
In animal cells only:
Lysosomes(Flagella)
Self-Check
Organelle Name
Function Part of Endomembrane
System?
In Bacteria? Plants? Animals?
Nucleus Store genetic info no P, A
Ribosomes
Rough E.R.
Smooth E.R.
Golgi
Plasma MembraneLysosomes
Vacuoles
Mitochondria
Chloroplasts
Cytoskeleton
• Shape/support
• Cell movement
• Internal transport
• Cell division
Unique to eukaryotic cells - essential to cell survival/function
Cytoskeleton overview
Three types of cytoskeletal elements:
Cytoskeleton Components
• Actin filaments (microfilaments)
• Microtubules • Intermediate filaments
• Localized at membrane
• Cell movement
Actin filaments
• Muscle fiber contraction
• Pseudopodia• Cytoplasmic streaming (plants)
• Radiate from center
• Internal transport, motile structures
Microtubules
• Inside flagella
• Inside cilia • Make centrioles
Extracellular Spaces – Cell wall
• In plants
- made of cellulose
• Thick
• cells connected
Why?• plasma membrane
• secondary wall
• primary wall
• Animal cells - glycoproteins Ex. collagen
• ECM – cell communication, movement
Extracellular Spaces – Extracellular Matrix
• Animal cells - three types
1. tight junctions (seal cells)
2. desmosomes (anchoring)
3. gap junctions (communicating)
Extracellular Spaces – Junctions
Lecture 2 concepts
- List at least 3 types of microscopy and pros & cons for each
- Explain differences between prokaryotic and eukaryotic cells
- *For each organelle mentioned, list the name, function and whether it is present in bacteria, plant, & animal cells*
- Name the three fibers of the cytoskeleton and describe the function for each one
- Discuss the cell wall in plants, include purpose and material
- Explain the extracellular matrix of cells, include purpose and material/composition
- Describe how plant and animal cells are connected
- Write out a list of new terminology and provide descriptions