In one of our previous articles, we briefly touched on the differences between peptides and proteins. Even though they are basically built up of the same building blocks (amino acids), we can generally say that peptides differ from proteins in that they are shorter (peptides usually come in chains of 2-50 amino acids), and have a simpler structure since proteins can combine multiple amino acid chains.
What Are Amino Acids?
As we already said, amino acids are the building blocks of proteins (and peptides), but what exactly are they? In the chemical sense, amino acid is an organic compound consisting of two parts:
- Amino group – made up of nitrogen and hydrogen atoms
- Carboxylic acid group – made up of carbon, oxygen and hydrogen atoms
Each amino acid has something called a side chain, which is what differentiates them from one another.
In total, there are 20 different types of amino acids involved in building up proteins, of which nine are essential, meaning our body can not synthesize them on its own – they must be supplied through our diet.
What Are Peptides?
Peptides are short chains of amino acids, 2-50 in length, held together by peptide bonds. Since we already covered this topics in great length, we’re going to keep it short and go over the necessities you should know:
- Chain length – peptides are shorter in length, compared to proteins, and their structure is less complex
- Building blocks – just like proteins, peptides are built up of amino acids, held together with peptide bonds
- Roles – since there are over 7400 different types of peptides within our body, it doesn’t come as a surprise to see them performing all kinds of different functions such as acting as hormones, neurotransmitters, signaling molecules, immune system regulators and many more
- Structure – the peptide structure is determined by the amino acid length and sequence
The Function Of Amino Acids
Besides being used to create proteins, amino acids can also:
- Break down food
- Grow and repair various tissues within our body
- Serve as energy sources
- Affect hormones and brain chemicals
- Build muscle
- Boost immune system
- Aid in digestion
Difference Between Amino Acids And Peptides
If you’ve been following along closely, you pretty much know the difference, but let’s use a metaphor to further explain this difference…
If we used construction terms, amino acids are the bricks and peptides/proteins are different types of houses. Of course, you can order these “bricks” in many different ways, to a varying degree of complexity and end up with either peptides or proteins.
So, the biggest takeaway here is that there is really no comparison between the two, though they are similar we cannot compare them using the same merit.
References:
1. KAUFFMAN, SA, JELENFI, DP, VATTAY, G. “The clock of chemical evolution”.
2. LEHNINGER, AL, Nelson, DL, COX, MM (2000). Lehninger principles of biochemistry, 6th ed. New York: Worth Publishers. Chapter 3: “Amino acids, peptides and proteins”.
3. TRÖNDLE, N, “Different methods of protein analysis – characterisation of proteins and peptides” [Genaxxon bioscience]
4. MARENGO-ROWE, AJ. “Structure-function relations of human hemoglobins” Baylor University Medical Center Proceedings 2006; 19: 239-245.
Our support team is at your service, ensuring customer satisfaction.
