Biology:Biochemistry vs. Chemistry

[Curmudgeon]

Originally Posted by johndallman

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

So it does, I missed the continuation on B170 when I was checking optional specializations.

[whswhs]

Originally Posted by 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.

You've omitted sulfur, which is an essential constituent of proteins, as it's part of the amino acid cysteine/cystine. This is both a structural determinant and a catalytic site.

I'm used to the list being C, H, O, N, S, P; the ions such as halogens and various metals are left off to the side—though biochemistry does study chlorophyll, which contains magnesium, and heme, which contains iron. O and S are also in the same family; there are bacteria that offload hydrogen onto hydrogen sulfide rather than hydrogen oxide.

[ericthered]

The two are not subsets of each other, but are strongly related.

Chemistry is about a broad range of relatively simple chemical reactions.

Biochemistry is about a specialized hyper-complex set of chemical reactions that happen in cells.

I may allow for a generous default between the two, but they are not the same at all.

[Bruno]

As a layman but chemistry enthusiast, I understand the breakdown is roughly

Biochemistry: interested in the crazy complicated chemicals inside organic bodies, what they do, and what they do to each other. EG: "This snake venom causes local swelling and pain in humans, but it has 40 different proteins and compounds in it. What are they all doing?" - "Oh, interesting. Some have specific actions on mammals, and some have specific actions on invertebrates"

Organic Chemistry: interested in synthesizing said chemicals using laboratory processes, and exploring all the analogues of said chemicals. "I bet I can make some of those snake venom compounds in the lab, without needing a snake, or contaminating the sample with the other 39 compounds!" - "Great, now lets start making variations on the 40 compounds and see what they do to mice. I bet some of these nerve agents can be used to make local pain killers, and I think this one protein can be made to dilate blood vessels."

Inorganic Chemistry: Off in another section of the periodic table entirely, working on a shorter/higher yield synthesis of an industrial chemical, finding better aerospace alloys, or seeing what kind of kooky things you can get up to with uranium. There's a team at Nottingham University that figured out how to make a Uranium-Nitrogen bond. No particular goal in mind, other than "They said it couldn't be done" - but now both organic and inorganic chemistry now has a new unit they can attach on to various molecules to see how they react with this enormous uranium atom hanging off the end.

[Ulzgoroth]

In just about every case I've seen, biochemistry has been referring to the chemistry of proteins, more or less. Though you probably can find occasional protein-free RNA or even DNA biochemistry work, most of the stuff to study is going to be protein because when you get down to it that's where most of the magic happens. And sometimes when they're really looking for trouble there will be a lipid bi-layer involved.

Biochemists don't get to ignore elements that aren't found in amino acids, by the way. At best, the ionic content of your buffer is vitally important to the behavior of any protein. And metal ions, sometimes embedded in complex organic chemical frameworks, are essential components of the active sites of many proteins.

While biochemists certainly need to know a bit of general and especially organic chemistry, their work (like other biologists) tends to involve a lot of empirical testing of things which are much too complicated for us to make any kind of strong predictions from theory.

They're also focused on a much narrower range of chemical conditions than general chemists. Nearly everything has to be done in water, buffered to somewhere in a fairly narrow pH range, with a quite restricted salt concentration, sometimes with some detergent added. (Within that you still may need to fiddle with the details considerably to make things work!) Most of the chemist's selection of solvents will promptly denature the biomolecules they work with, and that's often irreversible at least as a practical matter.


EDIT: 'Analyze an ooze' is pretty cinematic science unless you've got a specific idea of what you're analyzing it for. If you want to figure out its broad chemical content that's very much Chemist work whether it's of biological origin or not. If you want to know what kinds of DNA it contains that's some kind of Biology but probably not Biochemistry. If you want to figure out what this ooze is and why it's here, you'll probably want:
-A chemical and toxicology analysis with hazmat handling to figure out whether it's hazardous and what kinds of hazard, as well as some general information about what it is.
-You probably want to do a microbiological analysis to try to figure out what microbes are in it and whether it needs to be considered a highly hazardous infectious material.
-If it's largely water with a lot of organic materials in, you likely want to do a DNA analysis on some of it to get clues about what kind of organism(s) it came from.
-If it has specific activities you want to know more about, you may want a biochemist to fractionate a sample and try to purify the component of the ooze that's responsible for that activity.
-You may want a zoologist/botanist/ecologist of some kind to tell you about what kind of organisms in the environment could have been responsible for this.

[whswhs]

In university curricula, biochemistry courses are often included in chemistry departments, and count as credit toward a chemistry major. What GURPS provides is a simplification. It's a bit messed up by biology being VH and chemistry being H; that says that Biology (Biochemistry)-IQ costs 4 points but Chemistry (Biochemistry)-IQ costs 2 points.

Are they the same specialization at two different prices? Or are they two different fields?

(This problem arises with other interfacial fields: physical chemistry, chemical physics, biophysics, astrophysics, geophysics, geochemistry, psychobiology, mathematical physics. . . .)

Obviously a biochemist has to know some chemistry, at least at a basic level, and therefore a roll vs. Biology (Biochemistry) or vs. Biology in general would allow knowing some minimal chemical facts and processes. On the other hand, a biologist would probably not know the chemistry of the oxidized forms of metals, or the rates of inorganic reactions, or much of anything about elements that are not carbon and are not interacting with carbon. Conversely, a chemist would probably not know the details of what the molecules are doing in living bodies.

When I took biochem at UCSD, it was after two quarters of general chem, one of physical chem, and two of organic chem. But I never took any serious upper division chem courses.

[mukibear]

when you take freshman biology in college, usually the first semester is cytology (cells) plus biochem. the atp cycle in heterotrophs, whereby adp become atp and the citric acid cycle in plants are the big things. in first semester biochem, it's all about amino acids then enzymes. the second semester of freshman biology is a bit of botany, zoology, evolution and mostly ecology. if you want to study life and nature, tough it through bio101 and 102 and go for ecology.

organic chemistry doesn't really get into amino acids and enzymes, it's just about carbon compounds. i've never seen biochem as a part of a chem major, it's usually its own major.

[whswhs]

Originally Posted by mukibear

organic chemistry doesn't really get into amino acids and enzymes, it's just about carbon compounds. i've never seen biochem as a part of a chem major, it's usually its own major.

When I took organic chemistry in 1970, my textbook had chapters on saccharides, amino acids, and I think lipids. We got all that stuff before the biochem course started. On the other hand, I think we got the theory of oxidation-reduction of carbon compounds in biochem, which was taught in the biology department.

At UCSD back then, at least, if you were going to be a bio major you didn't take any bio till upper division. It was solid chem until your junior year. And then the core requirements were biochem, genetics, cell biology, and physical biochem; anything bigger than a cell was an elective. That was part of why I changed majors; I wanted to do organisms, and I was at the wrong school for that.

[Ulzgoroth]

Originally Posted by mukibear

when you take freshman biology in college, usually the first semester is cytology (cells) plus biochem. the atp cycle in heterotrophs, whereby adp become atp and the citric acid cycle in plants are the big things. in first semester biochem, it's all about amino acids then enzymes. the second semester of freshman biology is a bit of botany, zoology, evolution and mostly ecology. if you want to study life and nature, tough it through bio101 and 102 and go for ecology.

This is entirely school-dependent. I was a TA for a second-term freshman bio class, and it had no ecology, botany, or zoology - it was all genetics and evolution.

Originally Posted by mukibear

organic chemistry doesn't really get into amino acids and enzymes, it's just about carbon compounds. i've never seen biochem as a part of a chem major, it's usually its own major.

Amino acids are well inside the scope of organic chemistry. I expect it won't usually focus on biological reactions or anything involving proteins, but the chemistry involved there is certainly in-scope for Organic. Protein structure takes you out of the usual scope for organic chemistry though.

As for biochemistry, at my undergrad there was definitely not a biochem major, but there were biochem courses offered by both the bio and chemistry departments. (They were interchangeable for a bio major, a chem major was required to take the chem department biochem class.)

[Anaraxes]

You can argue that biochem is "just a specialization of chemistry". But by that logic all GURPS skills are just specializations of Physics.

It's a case of emergent behavior. The higher layer of behavior follows its own rules that are worthy of independent study. And while knowledge of the underlying layer might inform your knowledge of how the higher behaves, you don't normally think of it on that level of detail; nor can an expert in the lower layer automatically predict and understand the behavior of the higher layer.