Biology:Biochemistry vs. Chemistry

[Flyndaran]

How would they differ? It's seems like the first should fall under the second, but they're both Hard skills.

When studying a (formerly) living thing when would I need one versus the other?

[johndallman]

GURPS follows modern academic practice here, as is does for most sciences. The chemistry of living things is of the same order of complexity as the chemistry of everything else put together. Chemistry deals with a vast range of things, including very basic biochemistry. Biochemistry deals with a much narrower field, but its depth is far greater.

The overall subject seems to have ended up divided that way because it's a split into manageable-size fields for study.

For a living creature, you usually need biochemistry. For a deceased one, it can depend what you're trying to find out, and how long it's been dead.

[Flyndaran]

While that makes sense, there's no way to identify when something gets too complicated for basic Chemistry and requires Biology: Biochemistry.

And if one has high Biochemistry skill shouldn't Chemistry default to it and vice versa?

[johndallman]

Originally Posted by Flyndaran

While that makes sense, there's no way to identify when something gets too complicated for basic Chemistry and requires Biology: Biochemistry.

If it's part of a living creature's metabolism, it's likely Biochemistry. 3e had no Biology skill, making the specialisations skills in their own right, which was to some degree realistic, but frustrating to players who haven't studied the fields themselves.

And if one has high Biochemistry skill shouldn't Chemistry default to it and vice versa?

Having a bit of Chemistry is necessary to learn Biochemistry in real life, but I'm not sure if this reaches the level of a whole point in Chemistry, as would be the case of it were a GURPS skill prerequisite. Some defaulting between the skills would make sense.

[Flyndaran]

It still seems like real life biochemistry is a specialization of chemistry, not a separate skill.
It's weird to imagine an expert biochemist unable to analyze unidentified ooze because it didn't come from a living thing. But have no trouble if it turned out to be decomposed slime molds poisoned by arsenic compounds.

[johndallman]

Originally Posted by Flyndaran

It still seems like real life biochemistry is a specialization of chemistry, not a separate skill.

It's weird to imagine an expert biochemist unable to analyze unidentified ooze because it didn't come from a living thing. But have no trouble if it turned out to be decomposed slime molds poisoned by arsenic compounds.

Skills in real life do not have the neat boundaries of GURPS. Our biochemist would be able to discover that the ooze wasn't from a living creature, and then have to start looking up analytical methods they didn't regularly use, if they didn't have a general chemist to pas the job off to.

[Curmudgeon]

Originally Posted by Flyndaran

While that makes sense, there's no way to identify when something gets too complicated for basic Chemistry and requires Biology: Biochemistry.

And if one has high Biochemistry skill shouldn't Chemistry default to it and vice versa?

It isn't that Biochemistry is too complicated for basic Chemistry, exactly. It's a different orientation. Biochemistry is primarily interested in the formation and reactions of carbohydrates, proteins, lipids and nucleic acids, as well as the formation of polymers from monomers. A related but different branch of biology is molecular chemistry which is interested in how molecules regulate formation of these substances, for example gene regulation in DNA.

There was a biochemist, his name escapes me at the moment, who used to do a PBS special on cholesterol during pledge week a decade ago. A You Tube video by Dr. Eric Berg on Blood Sugar and Diabetes is essentially another biochemist explaining things in layman's terms. That is the sort of thing biochemists do.

A biochemist would probably not be very useful for a deceased being as the chemical processes that he normally studies would have ceased. OTOH, he could probably study the chemical reactions of the being as it decomposes and explain how it decomposes.

By the way, the two skills are not both Hard. Biology and its optional specialization Biology (Biochemistry) are Very Hard (B180), Chemistry is Hard (B183). GURPS itself provides no default between the two by RAW. A biochemist really ought to have the Chemistry skill at a level not too far removed from his skill level in Biochemistry to reflect his training in Chemistry at the university level as part of his degree program. I might allow a player to make some "default" rolls if he left Chemistry off his character sheet but only if he genuinely overlooked it and plans to remedy the deficiency in short order.

I might allow a character a roll at a penalty to perform a synthesis of a compound, depending on how close the synthesis sounds to Biochemistry. For example, synthesizing acetylsalicylic acid [Aspirin] from acetyl and salicylic acid, sounds very much like organic, but not bio-, chemistry, so I might allow that at a -2 to his effective biochemistry skill. Synthesizing sulphuric acid on the other hand, while fairly basic, is definitely Inorganic Chemistry so I might rate it at -4 or even -6 as a penalty for being out of field with a +2 or +4 bonus, since it is a fairly simple high school experiment and not a complex operation. In other words, it's something that our biochemist has actually done at some time or other, so he has actual hands on experience but it's not something that comes up all that often in his practice, so he probably has to really think about it to get it right.

[Flyndaran]

Still it seems like there should be some default between the two. But I also don't see why any other branch of Biology would get such a default.
I keep waffling in my own views.

[Curmudgeon]

Biochemistry is by its nature somewhat restrictive. The six major elements involved are carbon, hydrogen, nitrogen, oxygen, calcium and phosphorus. Because nitrogen and phosphorus belong to the same family in the periodic table, they react similarly to the same chemicals. Those five families that are represented cover a bit more than half of the periodic table and you can probably find some of the missing families among the roughly eighteen elements that have minor occurrences in biochemistry but even so, he has probably never dealt with the elements of the lathanide and actinide series in the table.

[johndallman]

Originally Posted by Curmudgeon

By the way, the two skills are not both Hard. Biology and its optional specialization Biology (Biochemistry) are Very Hard (B180)...

Optional specialisations are learned as if they were one level easier. B169-170.