Oxidation is the loss of electrons, whereas reduction is the gain of electrons. The mnemonic is OIL RIG: Oxidation Is Loss, Reduction Is Gain.
Oxygen is highly electronegative (second only to fluorine), meaning that it will strongly pull electrons.
The reason that oxygen is so important for respiration is because of its high electronegativity. It is used as the final electron acceptor in a chain of chemical reactions that are used to convert high energy molecules that you’ve eaten into different high energy molecules that your body can use.
Think of the analogy of a staircase and a ball. The ball is an electron and the stairs are energy states of different molecules along the metabolic pathway. As the ball goes down the stairs, the electron loses energy (which is usually converted to ATP or NADH). At the bottom of the stairs is oxygen, once the electron gets there, it doesn’t have anymore potential energy to lose, unless maybe you have some fluorine around.
An oxygen missing an electron (an oxygen radical) is highly reactive. It’ll just steal an electron from whatever molecule is nearby. That may be DNA or any other molecule that you’d rather keep intact. Antioxidants are helpful as electron donors, neutralizing radicals before they do damage.
This is my understanding, at least. It’s been a while since I took chemistry.
peregrin5@lemm.ee 1 day ago
Oxidation is how red blood cells collect oxygen to pass to the rest of the body. In fact it is iron in hemoglobin that “rusts” to collect the oxygen.
Antioxidants have nothing to do with this.
rhombus@sh.itjust.works 8 hours ago
The process you’re thinking of is oxygenation, not oxidation. Oxygenation is the binding of oxygen to other molecules, oxidation is the loss of electrons. When the iron in hemoglobin oxidizes (from Fe2+ to Fe3+) it stops binding with oxygen, and if it oxidizes further (to Fe4+) it can start oxidizing other molecules in your body. Your body has enzymes to reduce the iron back to a reactive state, but antioxidants also play a role in reducing oxidized molecules.
peregrin5@lemm.ee 8 hours ago
It’s actually the opposite. When the oxygen binds to the iron it changes from Fe+2 to Fe+3 so the binding of oxygen to the iron in hemoglobin is an oxidation process. At that point it can’t take more oxygen until it releases it in a reduction reaction.
The term “oxidation” is originally derived from reactions where a substance combines with oxygen but has since been generalized to any reaction where an electron is given up. So “oxidation” is the broader term and “oxygenation” is the specific oxidation reaction that results in binding oxygen.
Winter_Oven@piefed.social 1 day ago
ooh, then I must have gotten the terms wrong...
What I was thinking were the free radicals that are generated during basically most oxygen related reactions in the body, I thought that was called oxidation (at least, in terms of the body).
So, you know anything about how (or if) antioxidants are used against free radicals?
ThoGot@feddit.org 1 day ago
That actually depends on the type of antioxidant. The body has certain innate antioxidants (e.g. enzymes like catalase) to deal with reactive oxygen species but antioxidants that you get through your diet are also very important in that system (like vitamin c and e to prevent oxidation of cell membranes for example). Also some phytochemicals (like polyphenols) can act as an antioxidant.
Greyghoster@aussie.zone 1 day ago
Thanks, this is an unexpected image and a fun fact for the next party.