• http://www.sirinet.net/~jgjohnso/aphome.html
• This is a GREAT website made by another AP Biology teacher in Oklahoma. Check it out. There are practice quizzes, notes etc etc.
• Review your metric measurements:SEE PAGE 103
• n = 10-9 m
• µ = 10-6 m
• mm = 10-3 m
• cm = 10-2 m
Using energy gradients (energy at each step) to help do work. Staying away from equilibrium. (like respiration!) how is a human an open system?
Closed system
Open system
Figure 7.3Figure 7.3cell fractionation, centrifugecell fractionation, centrifuge
What are the largest organelles/parts of a cell that fraction off into the pellet first? What are the smallest? (last) (What are microsomes?)
Peroxisomes Peroxisomes
• Consume deadly free oxygen within the cell, transport it to mitochondria.
• Enzymes transfer hydrogen to oxygen, producing hydrogen peroxide (H2O2)
• H2O2 is also toxic to a cell, and an enzyme made by the peroxisome can break down H2O2 into O and H2O when necessary.
The cytoskeleton maintains the cell’s shape and more… p.120
Microtubules
largestcompression resisting (girders)made of tubulin (tube)large scale movements: chromosomes flagella, cilia,
Microfilamentssmallesttension bearing (resists pulling)
made of actinmuscle contractioncytoplasmic movements (see 7.27)
Intermediate filamentsintermediate size tension bearing (resists pulling)made of keratin-type proteinsanchors organelles
Microfilaments and movement
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http://homepage.ntlworld.com/postalmicsoc/spagfr1.jpg
http://www.accessexcellence.org/RC/VL/GG/images/Fig_16.36.jpg
http://ccollege.hccs.cc.tx.us/instru/Biology/AllStudyPages/Cells/Plant_Animal.htm
http://www.emc.maricopa.edu/faculty/farabee/BIOBK/bilayer.gif
Amphipathic nature of the phospholipid bilayer
What can diffuse through the hydrophobic zone of the bilayer and what cannot?
How can molecules get into a cell if they are not able to diffuse through the membrane directly?
The endo-membrane system
Why are there so many different organelles and so many different membranes inside a cell?
Answer: Gives the cell the ability to do many different specialized reactions at one time, in different parts of the cell—complexity!
• Paramecium
• Contractile vacuole
http://www.sirinet.net/~jgjohnso/homeostasis.html
• In your book, page 145 questions 6-10 practice
The Cell = 0.03M sucrose 0.02M glucose
Environment = 0.01M sucrose 0.01M glucose 0.01M fructose
The membrane is permeable to everything but sucrose.