Can animals synthesize proteins?


Well, I’m vegan and I’ve heard a lot of vegan saying that animals get all their proteins from plants, because they can’t synthesize proteins. Some friends have told me that it’s a lie and some other friends have told me that animals form other proteins with plant proteins.

In: Biology

No sure where your friends are getting their information, but animals can synthesize protiens. All life can for that matter, and it would be impossible for life to continue if they weren’t able to do so.

Proteins are encoded by DNA which is then transcribed into mRNA and translated by protein assembly units called ribosomes.

Protiens are made of building blocks called amino acids which are mostly synthesized by the body, there are a few which we (and animals as well) cant make ourselves and get from plants (This is possibly what your friends are talking about and just mixed up the terminology).

You are saying it like proteins are one thing. In fact there are millions of different proteins and they are all synthesized in the organism that require them. Proteins are put together from 20 different types of amino acids. When food is digested the protein in the food is broken down into its amino acids which can then be used to make new proteins. As for synthesizing amino acids this varies a lot between different organisms and the different amino acids. In general plants have to synthesize all their amino acids, but the ratio in plants is not the same as in animals. So animals have to synthesize some amino acids but do not have to synthesize all the amino acids they need, these are called essential amino acids. For humans this consists of nine different amino acids. However it is possible to get enough of these through a vegetarian diet however as plants have different ratios of amino acids then humans need you often have to eat more protein then if you got your protein from meat in order to get enough of the essential amino acids.

Your friend is on the right track but maybe not seeing the full scope of their answer. All proteins are made from amino acids, these are like building blocks and with only 21 amino acids your body can build the millions of different proteins that it needs. For humans, 9 of these amino acids cannot be made by your body, the other 12 it can synthesize if needed. If you are not getting these 9 essential amino acids your body will suffer from a protein deficiency. Even if you are eating foods that have protein, they may not be the right proteins. Now this is easy for omnivores as any animal meat contains all the essential amino acids. Vegans however do need to know that they are getting these amino acids from the right plants as different plants have a different combination of them. Quinoa happens to be a grain that does contain all 9, while some combinations like rice and beans together cover the 9 essentials. Do some internet searches on “complete proteins” to get more info on what vegan-friendly foods have your 9 essential amino acids.

Cows for example, apparently have 10 essential amino acids, but they are also better at breaking down plant matter and can get nutrition from food that we could not. So their bodies still go through the same process as ours. Eat some amino acids, make some, and put them together to build proteins.

Edits: fucking autocorrects. Always making me sounds like a lunatic…