• 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

Negative G = a loss of free

Energy

The products have less energy than the reactants, EXERGONIC

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?)

The endomembrane system’s interconnectedness. All membranes are the same bilayer.

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.

• Fig. 7.19

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

•

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!

Animal cells and osmosis

http://www.sirinet.net/~jgjohnso/table5-1.jpg

• 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.

• Unless cited, most slides/pictures were taken from the Campbell Reece Mitchell textbook, BIOLOGY, 2000. Instructor CD-Rom