Updated: Mar 31
By: Tony Wang
Nutrition is commonly referred to as the process by which food necessary for health and growth is obtained, consumed, and absorbed by living organisms. Animals and plants, both of which are living organisms, require sufficient nutrition in order to survive. However, unlike a majority of plants, animals must consume other living organisms in order to survive. They must consume these other living organisms in order to obtain the energy and organic molecules necessary to build up new cells and tissues. With that being said, there are a wide variety of diets among the millions of species of animals that live on our planet.
Herbivores, such as horses, rabbits, giraffes, deer, and elephants, mainly eat plants and algae. On the other hand, carnivores, such as lions, polar bears, wolves, tigers, and spiders primarily eat other animals. Omnivores, such as rats, dogs, and humans, are a bit in the middle, as they regularly consume animals as well as plants and/or algae. As such, omnivores can survive on either a herbivore diet or a carnivore diet.
Although herbivores typically eat plants, and carnivores usually eat other animals, a majority of animals are opportunistic eaters. This means that they can eat foods outside of their standard diet. For instance, even though horses are herbivores, they may occasionally eat bugs or even chicken eggs.
Interestingly, microorganisms such as bacteria are not considered “animals'' when eaten because they are unavoidable in every animal’s diet.
Now, let’s get a bit more into the science of things. An adequate diet for an animal must perform three essential nutritional jobs: provide chemical energy for cellular processes, build blocks for large organic molecules, and provide essential nutrients. The first job is very important, as the activities of all cells, tissues, and organs of an animal depend on massive quantities of chemicals. This energy is what is used to produce ATP (adenosine triphosphate), which powers processes ranging from DNA replication and cell signaling to growth, vision, and flight. To meet the need for ATP, animals need to frequently ingest and digest these nutrients, especially macromolecules such as carbohydrates and proteins.
Additionally, an animal’s diet must provide essential nutrients, which are substances that an animal requires but cannot assemble from simple organic molecules. These include many vitamins and minerals, essential amino acids, and essential fatty acids. All organisms require a standard set of twenty amino acids in order to make a complete set of essential proteins. Microorganisms and most plants can normally produce all twenty on their own.
Vitamins are organic molecules that are required in the diet in very small amounts. Dietary minerals are inorganic nutrients, such as iron and sulfur, that are usually required in small amounts. A diet that lacks one or more essential nutrients or is consistently in low supply of the chemical energy that the body requires results in malnutrition, a failure to obtain adequate nutrition.
Overall, in order to survive and produce offspring, all animals, including humans, must carefully balance their constipation, storage, and use of food. Eating too much food, too little food, or the wrong mixture of foods can all endanger an animal’s health. Most wildlife animals have not only succeeded in determining what diet works for them, but are also able to adapt if their usual food sources are unavailable. However, many humans today fail to meet their nutritional needs, whether it be due to unfortunate circumstances or malpractice. In fact, malnutrition affects one out of four children worldwide and has negative impacts on health and survival. It is essential that we solve this problem, as healthy people create a happier and stronger society.
What Did You Learn?
1. Why are so many animals opportunistic consumers?
As stated earlier, animals are split into three broad categories of consumers: herbivores, carnivores, and omnivores. However, a majority of consumers are opportunists, meaning that they will eat whatever is present in their environment that can help them survive. Most animals are forced to be opportunistic consumers, as, in nature, the availability and quantity of a food supply can fluctuate very often.
2. What is ATP and how is it used?
ATP, or adenosine triphosphate, is “a compound consisting of an adenosine molecule bonded to three phosphate groups.” It is present in all living tissue and is, essentially, the battery that all living things use to function. ATPs contain energy, which they release through the breaking of their phosphate linkage. Once this energy is used up, the ATP becomes ADP, which are, essentially, dormant versions of ATP. Energy can be stored in ADP through the building of phosphate linkages, and once the phosphates have all been linked together, can become ATP.