There are three macro-nutrients:
Macro-nutrients provide calories, or energy.
The body needs large amounts of macro-nutrients to sustain life,
Protein provides calories.
One gram of protein contains 4 calories.
One gram of fat has 9 calories
When protein is broken down in the body it helps to fuel muscle mass, which helps metabolism, it helps the immune system to stay strong and helps to stay full.
The structure and function of our pets’ bodies depend on proteins.
Proteins are large molecules that cells need to function properly.
Protein consists of amino acids, and amino acids are the building blocks of protein.
Amino acids are organic molecules that consist of carbon, hydrogen, oxygen, nitrogen, and sometimes sulphur.
It is these amino acids, that synthesise proteins and other important compounds in the body, such as creatine, peptide hormones, and some neurotransmitters.
There are around 20 amino acids.
These amino acids can be arranged, each with a specific function.
The regulation of the body’s cells, tissues, and organs cannot happen without them.
Plants can synthesise all of the amino acids, animals can’t.
Plants can grow in a medium containing inorganic nutrients that provide nitrogen, potassium, and other substances essential for growth.
They utilise the carbon dioxide in the air to form organic compounds such as carbohydrates.
Animals have to get organic nutrients from outside sources.
Because the protein content of most plants is low, very large amounts of plant material is needed by animals such as cows, that eat only plant material to meet their amino acid requirements. Non-ruminant animals, especially carnivores get their proteins predominantly from animals and their products e.g. meat, and eggs as they are more bio-viable compared to plant-based protein
The seeds of legumes are being used to prepare inexpensive protein-rich food
The protein content of animal organs is much higher than that of the blood plasma.
Muscles contain about 30 percent protein, liver 20 to 30 percent, and red blood cells 30 percent.
Higher percentages of protein are found in tissues with a low water content (bones, and other organs).
The high protein content of some organs does not mean that the importance of proteins is related to their amount in an organism or tissue, some of the most important proteins, such as enzymes and hormones, occur in extremely small amounts.
The importance of proteins is related to their function.
Enzymes, which are the catalysts of all metabolic reactions, enable an organism to build up the chemical substances necessary for life
Life without enzymes is not possible.
There are several protein hormones with important regulatory functions.
In all vertebrates, the respiratory protein haemoglobin acts as oxygen carrier in the blood, transporting oxygen from the lung to body organs and tissues for example.
A large group of structural proteins maintains and protects the structure of the animal body.
Protein is an essential nutrient, or macro-nutrient, but not all the protein eaten converts into proteins in the body.
When eating foods that contain amino acids, these amino acids make it possible for the body to create, or synthesise, proteins.
If some amino acids are not consumed, the body will not synthesise enough proteins to function correctly.
The main functions of proteins in the body are to build, strengthen and repair or replace things, such as tissue.
They can be:
- Structural – like collagen
- Hormonal – like insulin
- Carriers – for example, haemoglobin
- Enzymes – such as amylase
All of these are proteins.
Keratin is a structural protein that strengthens protective coverings, such as hair.
Collagen and elastin, to have a structural function, and they also provide support for connective tissue.
Most enzymes are proteins and are catalysts, which means they speed up chemical reactions.
They are necessary for respiration in cells for example.
Types of protein:
There are three types of protein foods:
Complete proteins: These foods contain all the essential amino acids.
They mostly come from animals, such as meat, dairy and eggs.
Incomplete proteins: These foods contain at least one essential amino acid, so there is a lack of balance in the proteins.
Plant foods, such as peas, beans, and grains
Complementary proteins: These refer to two or more foods containing incomplete proteins. Examples include rice and beans.
Protein deficiency due to a low intake of protein in a species appropriate diet is unusual however, a lack of protein in the diet is a matter of concern, as these can be life-threatening.
A deficiency can arise if a pet has a health condition, such as:
- certain genetic conditions
- the later stages of cancer
- difficulty absorbing nutrients, due, for example, to IBS
- Other variables include the proportion of amino acids available in specific protein foods and the digestibility of individual amino acids. It is unclear how protein metabolism affects the need for protein intake.
Very low protein intake can lead to:
- weak muscle tone
- skin lesions
- loss of muscle mass
- stunted growth.
As we’ve learned above, proteins that come from animal sources are more bio viable for our carnivorous pets.
This means that when you feed a balanced raw meat diet, your pet will get all the nutrients he/she needs.
To create such balance diversity in protein source as well as different cuts and organs is essential, as they all play a different role within the body and thus vary in nutritional values.
Each page within the Protein Explained category, will explain each protein individually and give its nutritional break down
Lyle McDonals: The protein Book
Gregory Petsko: Protein Structure and Function
International Library of medicine https://ghr.nlm.nih.gov/
Encyclopedia Britannica https://www.britannica.com/
Harvard School of Public Health
Medical News Today https://www.medicalnewstoday.com/
Lice Science https://www.livescience.com/
Web MD https://www.webmd.com/
Science Notes https://sciencenotes.org/
Genetic science Learning Centre https://learn.genetics.utah.edu/