In biology, the central principle is that genetic information flows in one direction—from DNA to RNA to protein. This process, known as protein synthesis, is how your body creates the proteins essential for building muscle, maintaining organs, and keeping your body healthy. DNA provides the blueprint, and RNA delivers the instructions to produce proteins. Discovered by Francis Crick, the process of protein synthesis is fundamental to life. Understanding how protein synthesis works can help you make smarter choices about your health, like building muscle and staying strong.
Protein synthesis is how cells make proteins. Understanding this concept is important if you are working to build and maintain muscle mass. Learn how protein synthesis occurs, why it's important, and how to encourage it in your body.
What is Protein Synthesis?
Protein synthesis is the process by which cells in your body make proteins. Proteins are molecules that do most of the work in cells. Your body needs proteins to regulate and give structure to tissues and organs and manage bodily functions.
Some of the primary functions of proteins include the following:
- Antibodies (binds to viruses and bacteria to protect the body)
- Enzymes (carry out chemical reactions in the cells)
- Messengers (transmit signals between cells, tissues, and organs)
- Structural (allow the body to move and support the cell)
- Transport/Storage (carry atoms within cells and throughout the body)
Amino acids are the building blocks of proteins. There are 20 types of amino acids involved in protein synthesis. Scientists classify these amino acids into essential, nonessential, and semi-essential. Our body cannot synthesize essential amino acids, so we must acquire them through eating and drinking. There are 9 essential amino acids.
Our bodies can produce non-essential amino acids. However, we need semi-essential amino acids, such as arginine and histidine, during pregnancy, adolescence, and trauma recovery because our bodies may not be able to produce them in sufficient amounts.
The order of the amino acids determines the structure and function of the protein. Genes in your DNA code the sequence of amino acids. Proteins often consist of single polypeptide chains. Some can have two or more peptide chains. These arrangements are called the protein's quaternary structure.
The Importance of Maintaining a Healthy Balance of Proteins in Your Cells
As you age, your proteostasis (the ability to maintain the building and turnover of proteins) can decline. This can lead to a higher risk of diseases such as Alzheimer's, Type 2 Diabetes, and other age-related diseases. These diseases often present with protein denaturation, which alters and unfolds the structure of proteins. This process is usually irreversible.
Since proteins are essential to our bodies, understanding how protein synthesis works can help you make decisions about your workout and food choices to encourage more efficient protein synthesis and help prevent the onset of age-related diseases.
How Does Protein Synthesis Work?
DNA, or genome, carries the instructions to make proteins. However, DNA resides in the chromosomes, which stay inside the nucleus of a cell. So, the eukaryotic cell must get the DNA template for proteins to produce them in the ribosomes. Protein synthesis has two steps. The first stage is transcription, the beginning of gene expression.
A messenger RNA (mRNA) molecule carries messages to cells. RNA molecules are small enough to pass through the nuclear membrane. There are several types of RNA. So, to get the instructions about producing protein molecules outside of the nucleus, an mRNA needs to transcribe the instructions to carry them to the production site.
The gene that is being transcribed has three regions: a promoter, a coding sequence, and a terminator.
From DNA to Protein: The Intricate Journey of Transcription and Translation
Transcription occurs when the enzyme RNA polymerase binds to a gene's promoter. The promoter is a region on a gene. It signals the strand of DNA to unwind using a methionine start codon, allowing the enzyme to read the base pair of the DNA strands. The four bases of RNA are adenine, cytosine, guanine, and uracil. Then, the enzyme makes complementary bases in a strand of mRNA.
Next, elongation occurs. Nucleotides are added to the mRNA strand. At the end of transcription, the RNA polymerase copies the terminator, or stop codon, and detaches from the DNA molecule, completing the mRNA strand.
Before the pre-mRNA can leave the nucleus, it must undergo some modifications to mature, such as splicing, editing, and polyadenylation. Regions on the gene called introns are removed during this process, allowing the mRNA to make more than one protein. After these modifications, mRNA moves to the next stage.
Translation is the second stage of protein synthesis. Essentially, this is where the body reads the genetic code to make the protein. Ribosomes are cellular machinery inside each cell. They have two subunits that lock around mRNA. Then, they travel along the mRNA molecule to read it.
Once the ribosome reads the codons in mRNA, molecules of transfer RNA (tRNA) bring amino acids to the ribosome. The tRNA molecule has an anticodon that carries the amino acid. These anticodons bind with the mRNA, and then the tRNA gives up its amino acid. The ribosomal RNA (rRNA) then forms bonds between the specific amino acids useful for growing polypeptide chains.
After the chain of amino acids is completed, it may undergo other changes to modify the protein for its specific job, completing protein synthesis. Then, the ribosomes release the protein into the cytoplasm.
Why Is Protein Synthesis Important?
Muscle proteins break down during exercise. To repair the damage, you need to consume more protein to build up your proteins. You can lose muscle size and strength if protein breakdown is faster than protein synthesis. So, if you are going to the gym and working your hardest but not replenishing your protein stores, you may not see the gains you'd like.
Also, older men can experience muscle breakdown as a part of aging. Sarcopenia is when you lose muscle mass, strength, and function. Your muscle mass decreases by about 3-5% per decade after age 30. After age 60, that number increases.
Sarcopenia can make daily activities difficult. It affects the musculoskeletal system, putting people at risk of frailty, falls, and fractures. So, to stay independent and healthy, it's important to maintain healthy, strong muscles as you age.
Muscle hypertrophy happens when muscle cells grow. You want protein synthesis to occur faster than breakdown to encourage this growth. So, you should promote protein synthesis to aid in muscle growth, especially while you work out.
The Role of Testosterone and Thyroid Hormones in Protein Synthesis
Both testosterone and thyroid hormones play crucial roles in muscle protein synthesis, helping the body build and maintain muscle mass. Together, these hormones regulate protein production, energy levels, and overall muscle health.
Testosterone's Role in Muscle Growth
Testosterone is a key hormone that stimulates muscle protein synthesis, which your body uses to repair and build muscle fibers. It promotes muscle growth by increasing the production of proteins and enhancing the effects of growth hormone. Testosterone also helps prevent muscle breakdown, making it essential for anyone looking to build or maintain muscle mass, especially as they age. Lower testosterone levels, which naturally decline over time, can result in reduced muscle size, strength, and recovery.
Thyroid Hormones and Muscle Metabolism
Thyroid hormones, specifically triiodothyronine (T3) and thyroxine (T4), regulate your body's metabolism, affecting how efficiently your cells use energy. This energy regulation directly impacts muscle protein synthesis, helping your body repair muscle tissue after exercise. When thyroid hormone levels are balanced, they support muscle growth by providing the energy needed for efficient protein production. However, low thyroid levels (hypothyroidism) can slow metabolism, leading to muscle weakness, fatigue, and reduced muscle protein synthesis. On the other hand, high thyroid levels (hyperthyroidism) can cause muscle breakdown by speeding up metabolism excessively, sometimes leading to muscle loss.
Maintaining Hormonal Balance
Both testosterone and thyroid hormones play critical roles in muscle health, and maintaining their balance is key to supporting muscle growth and preventing muscle loss. If you're experiencing symptoms of low testosterone, like fatigue, muscle weakness, or difficulty gaining muscle, it could be due to testosterone or thyroid hormone imbalances. Addressing these imbalances can help improve protein synthesis and recovery, keeping you active and healthy.
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What Stimulates Protein Synthesis?
To build muscle, your body must continually synthesize and break down proteins, a process called turnover. Muscle protein synthesis is stimulated by three of the nine essential amino acids: leucine, isoleucine, and valine, also known as branched-chain amino acids (BCAAs). These amino acids are found in meat, dairy, and legumes.
Some evidence suggests that consuming protein after exercise may stimulate protein synthesis. Milk protein seems to work better than soy protein at encouraging protein synthesis. Whey protein and carbohydrates may also be important for promoting intracellular signaling. The type, timing, and amount of protein you consume before and after exercise can affect muscle mass.
Some people choose to take BCAA supplements to attempt to stimulate protein synthesis and reduce muscle breakdown. These supplements are also used to help with reduced brain function and may be used in people with advanced liver disease.
However, studies have found that BCAA supplements alone cannot support increased muscle protein synthesis. Rather, focusing on the right diet before and after exercise is important to promote protein synthesis.
What Foods Increase Protein Synthesis?
If you want to boost protein production to keep your mind and body in top condition, you want to add high-quality proteins to your diet. Experts advise that eating proteins before and after a workout can help to stimulate muscle growth. These proteins provide the essential amino acids your body needs to create proteins.
Here is a list of some high-quality proteins you can add to your diet to encourage protein synthesis:
Meats
- Poultry: Chicken, turkey, or other fowl are full of proteins that break down into amino acids. Chicken contains all 9 essential amino acids, which are essential to protein synthesis. Dark meat contains more vitamins and minerals than white meat. These cuts contain micronutrients such as riboflavin, thiamin, Vitamins B6 and B12, and minerals such as iron and zinc. When you prepare poultry, be sure to choose lean cuts. Limit the amount of fried or processed poultry that you eat. Opt for grilled, baked, or stir-fried options.
- Fish: Fish contain omega-3 fatty acids, which lowers the risk of heart disease and maintains brain health. Fish is a lean protein rich in potassium, a micronutrient used in muscle building. Fish also contains Vitamins D and B2, calcium, iron, zinc, iodine, phosphorus, selenium, and magnesium. This protein source can help improve sleep quality and promote brain development during pregnancy. This protein is also great for helping build strong muscles.
Other Sources of Protein
- Eggs: This protein source is rich in critical branched-chain amino acids. They also have lots of L-arginine and monounsaturated fats. These support weight loss and muscle building. They also contain choline, important for cell functioning, and vitamin D for muscle functioning.
- Dairy: Low-fat dairy contains casein protein. It slows muscle breakdown and helps to boost protein synthesis. Dairy also is a great source of calcium to help maintain bone health. It also contains potassium and vitamin D, which are important for musculoskeletal health.
- Beans: Although beans are not a complete source of amino acids, they still promote protein synthesis. If you combine beans with brown rice, you can have a vegetarian-friendly source of protein that gives you the amino acids you need for optimal protein synthesis. They also supply low-glycemic carbohydrates, which aid in speedy muscle recovery. They contain plenty of fiber, vitamins, and minerals and aid in lowering cholesterol, reducing blood pressure, lowering the risk of Type 2 diabetes, and supporting gut and immune health.
- Nuts and Seeds: Walnuts, sunflower seeds, peanuts, almonds, and pistachios are other sources of essential fatty acids. They also contain healthy fats, fiber, vitamins, and minerals to promote protein synthesis. Nuts and seeds are loaded with antioxidants, may reduce inflammation, and aid in heart health.
Food Prep to Optimize Protein Synthesis
So, now you know what to eat. What's a good way to prepare these foods before and after a workout to optimize protein synthesis?
Eating protein before a workout will help supply your body with the proteins it needs to fuel a good workout. However, you should time this meal correctly. If you eat immediately before a workout, you could have a stomach ache. Being too full can also lead to heartburn. Try eating a snack of a handful of nuts and yogurt 1-3 hours before your workout to ensure you have enough time to digest before exercise.
You could also opt for a smoothie full of fruits and veggies with a scoop of protein powder. Peanut butter and jelly sandwiches are a simple and easy way to give yourself a quick dose of protein before a workout. Peanut butter also makes you feel fuller, which can curb cravings.
After your workout, you want to restore your energy and protein levels. So, try eggs and toast. You could also drink a glass of milk or have a turkey wrap or sandwich post-workout. For more full meals, consider chicken, brown rice, veggies, salmon, and sweet potatoes.
These meals contain amino acids that help boost protein synthesis and prevent loss during breakdown.
Conclusion
Protein synthesis is a fundamental process that your body relies on daily to create and maintain the proteins needed for muscle growth, organ function, and overall health. Maintaining healthy protein synthesis becomes even more crucial as we age to prevent muscle loss, stay strong, and protect against age-related diseases.
By understanding how protein synthesis works, you can make smarter choices about your diet, exercise routine, and hormone balance. Incorporating high-quality proteins into your meals, timing your nutrition around workouts, and addressing potential hormonal imbalances, such as low testosterone or thyroid issues, can significantly improve your muscle-building efforts.
Whether you're aiming to build muscle, stay active, or improve your health as you age, promoting efficient protein synthesis is key. Small changes in your diet, workout habits, and hormonal health can greatly impact how well your body creates and maintains muscle. Take charge of your health by fueling your body with the right nutrients, staying active, and considering hormonal support.
With the right approach, you can boost your protein synthesis, build stronger muscles, and keep your body healthier for years to come.
