There are three things I can have done to my milk: pasteurization, homogenization, and the process of exposing the milk to the lactase enzyme, which causes the lactose to spontaneously break down into simpler sugars.
Is there a word for that last thing?
Digestion?
Catalization?
Some other possibilities:
biocatalysis
bioprocess
cultured ingredient production
or the technical term:
adding an ingredient
I think the way you should word it depends on the needs and wants of your audience.
Hydrolysis is the name for the type of reaction where lactose is broken down into glucose and galactose (lactase is a hydrolase). So you can call the process enzymatic hydrolysis of lactose.
Won’t “catalysis” do if you want to use a more general term?
There are a few google hits for “catalyztion”, which I guess is being used to distinguish the idea of using a catalyst from just describing the chemical process of catalysis. But I tend to think “catalysis” really covers both meanings. In every google hit I’ve looked at, the word “catalysis” in place of “catalyzation” sounds better to me.
Yeah, that was just a brain fart trying to come up with the term for the process of a catalyst in action. Catalysis is right.
Yes, lactase is a catalyst for the digestion of lactose because it speeds up the reaction by many orders of magnitude. That’s why enzymes exist. Otherwise digestion would be too slow a process to do us any good.
It’s an interesting exercise to think of what digestion would be like without enzymes. Would we become as slow as rocks to allow the time needed for molecules to hydrolyze on their own?
I wonder if multi-celled organisms are even possible without enzymes. Or can you go up to simple animals before they are necessary?
My immediate hunch is that enzymes are required for even the simplest organisms. It’s not just that they speed up reactions, the speeding up of specific reactions and not others means you get preferential reactions.
There is no notion of life without enzymes, pretty much by definition. An enzyme is any molecule that catalyzes a biochemical reaction, so all of metabolism consists of enzyme-catalyzed reactions, including the synthesis of biomolecules.
Without enzymes, you can have no organization and therefore no life - just soup.
The most fundamental enzymatic reaction in life is catalysis of replication of the genetic material. RNA molecules have much greater potential catalytic activity than DNA, and one of the leading hypotheses for the origin of life is RNA World, in which the genetic information was carried by RNA molecules that could catalyze their own replication.
Thanks. I assumed that an enzymeless world is a thought exercise like Flatland, but I’m not on a first-name basis with any single-celled organisms.
There’s a simpler problem here: If you define life as just self-replication, you do indeed get life without enzymes. You even get living rocks. You have, in fact, defined salt crystals to be alive: They have a crystalline structure which they will self-replicate endlessly given the right conditions. No enzymes required.
Biologists don’t think of crystals, or fire, or prions as being alive, but excluding them while including single-celled life requires a more subtle distinction. That distinction is metabolism, and metabolism requires enzymes.
Which is why it’s tricky to classify viruses, which don’t metabolize, but which instead use other cells to create copies of themselves. Prions work differently in that they direct modify proteins, but viruses at least hijack life processes, and can be said to be in control of a cell that they have successfully managed to get to make copies of itself. At that point in time, the virus is sorta alive in that it has managed to used cellular processes to reproduce itself, processes that require the rest of the necessities of life to take place. When the cell bursts with all the virus copies it dies, and the virus goes back to being not-really-alive until one of the copies manages to infect another cell.
As I understand it, there isn’t a lot of definitional uncertainty here: Viruses don’t metabolize, so they’re unambiguously not alive as far as biologists are concerned, even though medical people talk about “live virus” vaccinations and similar. Terminology doesn’t always match up precisely between fields, even closely-aligned fields. (I mean, physicists have two different metric signatures for flat spacetime!)
Somewhat more interesting are bacterial obligate intracellular parasites, like what causes leprosy: They’re not viruses, and they’re alive, but they can’t reproduce outside of the cells of their hosts. They skirt the boundary between alive and non-living matter more closely than viruses and prions do.
Nope. Very contentious issue.
Myself, I like the life definition of life as “a self-sustained chemical system capable of undergoing darwinian evolution” (which itself admittedly doesn’t put paid on the virus question because of possible quibbling over the meaning of “self-sustained.”)
My personal response to the “are viruses alive” question is to say that the entire host-virus system is alive. An individual virus is not alive, same as how an individual mitochondria or nucleus is not alive. That fits the definition that Darren Garrison posts, as long as you can tolerate a bit of fuzziness and overlap in the boundaries between “self” and “not-self”.