4. Dehydration (synthesis) = combine two molecules by taking an H2O away
Hydrolysis = breaking apart a molecule by putting an H2O in (the word lysis from latin means to break apart, like when a cell lyses)
5. Enzyme function depends on pH and temperature. Deviations from optimal causes denaturing of the enzyme since all they are are proteins. (again feel free to email me for more info)
6. Oxidation is the process by which a substance loses electrons and becomes more positively charged
Reduction is when a substance gains electrons and becomes negatively charged.
Together they form a redox reaction
Ex: Na --> Na+ + e- (Oxidation)
Cl + e- --> Cl- (Reduction)
Na + Cl --> Na+ + Cl- (Simply called NaCl or table salt) (redox reaction)
They might try to trick you and ask which is the reducing agent. The reducing AGENT is the one being oxidized, which in this case if Na. The oxidizing AGENT is the one being reduced, which is Cl since it gains an electron.
7. I have never done plant biology but here's a good thread for you to look at for the differences.
http://answers.yahoo.com/question/index?…
good luck with your exam :)