<p>wow, is it just me or was the 2008 Form B Free-Response Questions a lot easier than the ones we had. i could've actually done those well....
and they got to choose 3 out of 5 two times...... so lucky:(</p>
<p>i know i did so bad on the frq's.</p>
<p>Well basically fire can regulate ecological succession because once it destroys most/all of the land in the area, there will be more niches available for other organisms. First there will be the pioneer organisms that first set foot, which are most likely r-strategists (opportunists). Then over a long period of time, there will be more K-strategists and secondary succession will come to an end. Also, fire in a biome like chaparral would be beneficial because the plants can only enter their reproductive cycle after a large fire had occurred. So fire is a regulator in these two cases.</p>
<p>And predators are the regulators in prey-population dynamics because the population of prey will be dependent on how many predators there are. For instance, if there were many predators, there would be less prey. If there were less predators, there would be more prey. This inversely proportional relationship could have been graphed as well. </p>
<p>There's a lot more, but I can't really remember off the top of my head right now. And a question for everyone else: What's the difference between Form A and Form B. More specifically, who takes Form A and who takes Form B? Because everyone I know took Form A.</p>
<p>@ misterwang: i think someone earlier said that form b is for kids who took the makeup test. aka kids who had a really good excuse to study another day and get away with it</p>
<p>predator-prey question
i said some stuff about over population and the life cycle</p>
<p>I made sure to throw in the keystone predator thing, but in the fire one I didn't discuss about opening niches. I basically wrote how carbon is recycled from dead plant material so that the carbon can be once again fixed by autotrophs.</p>
<p>Form B is for people taking it outside of the US.</p>
<p>I wrote about keystone species (sea otters and kelp forests disapearing because of sea otter hunting) but got everything in between mixed up (somehow involved starfish and oysters, didn't really make sense). Would I still get credit you think?</p>
<p>skatj, what did you write that for?</p>
<p>EDIT: I was sick on a day of an AP test and my counselor says that since I don't have a doctor's note, I may possibly lose the ability to make up my test.. does anyone have any experience on this? I'm pretty nervous. :|</p>
<p>^the regulation of predator on prey populations</p>
<p>erm..if your explanation on why it's a keystone species was good, then I suppose so. Then you'd have to elaborate on it disappearing and the negative effects of it, I guess.</p>
<p>Do covalent bond link up the subunits to make the quartenary structure of proteins? Do covalent bonds even exist in proteins?</p>
<p>Tertiary structure is held by disulfide bridges.. the quaternary is when the chains of peptides fold into a 3d form.</p>
<p>Actually, the tertiary structure is also a 3-D form. The tertiary structure is the combination of several tertiary structures (subunits) to make up a fully functional protein.</p>
<p>sooooo...is it right if i said hydrogen bonding and van der waals interactions make the quaternary structure??? My teacher never taught us much about secondary or tertiary...he just basically said primary is the peptide bonds and quarternay is 3-D and has the bonds/interactions.</p>
<p>Actually, it doesn't seem reasonable for Van Der Vaals interactions to be able to hold gargantuan polypeptides together into quaternary structures (Van der Vaals are very weak forces).</p>
<p>I'd rather say that disulfide bridges (for example, those linking heavy and light chains of antibodies) account for quaternary structure.</p>
<p>Quaternary structure is the 3D form of SEVERAL polypeptides being put together (e.g. hemoglobin with 2 alpha and 2 beta polypeptide components). Tertiary is only 1 polypeptide folding into its 3D form.</p>
<p>primary = aa sequance
secondary = alpha helix & beta-pleated sheets due to hydrogen interactions between the common structure of the aa's (like everything BUT the R group)
tertiary = hydrogen bonds, van der waal forces, S-H bridges, ionic bonds between the R groups -> forms the specific shape based on the R groups
quaternary = bonds between multiple polypeptide chains (usually by hydrogen and van derwaal forces i think..)</p>
<p>had to memorize this for my class which was 10x harder than the AP.. we had like 2 full textbook pages just describing this.</p>
<p>I thought the test was just ridiculous. I hope they put a nice fat curve on the test :P</p>
<p>For the Protein:
Primary Structure- peptide bonds between adjacent amino acids.
Secondary- hydrogen bonds between adjacent carboxyl groups and amino groups resulting in alpha- helical segment and beta pleaded sheets.
Tertiary- Ionic bonds between "R" groups, Hydrogen Bonds between "R" groups. Disulfide bonds between "R" groups, and Hydrophobic interactions. The structure of the protein will be globular.
Quaternary-Ionic bonds between "R" groups, Hydrogen Bonds between "R" groups. Disulfide bonds between "R" groups, and other interactions among the "R" groups.</p>
<p>ok can we go on to the other questions and put this one to rest</p>
<p>let's say that i got 60 points on the MC (after all of the wrong questions had been weighted in) and 20-25 points on the FRQs. What score should I expect?</p>
<p>I know what princeton review says but this test was also harder than other ones and so the curve should be better, right?</p>