Download Homework 4

Full Name: _______________________________
Section (Th/Sa): ___________
Homework 4
1a. What types of molecules make up the membranes around your cells? (Hint, give 3.)
1b. What does semi-permeable mean and how are the molecules arranged in a membrane
to make it semi-permeable?
2a. Define the terms diffusion, osmosis, and concentration gradient.
2b. Give an example of the terms in 2a in your everyday life. For example, you could
say that there is a concentration gradient of wacky professors around PCC. The most
wacky professors are found on campus and as you move away from campus the
concentration gradient decreases.
3. On the back or on another sheet, draw a plant and an animal cell and include labels for
the names of organelles and structures. You must include these structures in at least one
of your drawings: nucleus, nucleolous, rough endoplasmic reticulum, smooth
endoplasmic reticulum, ribosome, mitochondria, central vacuole, golgi complex, vesicle,
lysosome, cell membrane, cell wall, chloroplast, centriole.