Protein Requirements Study Flashcards
Describe the composition of proteins.
Proteins are made up of carbon, hydrogen, oxygen, and nitrogen atoms, which are built from amino acids.
Explain the role of peptide bonds in protein structure.
Peptide bonds bind amino acids together to form polypeptides, which are the building blocks of proteins.
Define essential amino acids and their significance in diet.
Essential amino acids are those that must be supplied through the diet because the body cannot synthesise them.
How many amino acids are there?
20
List the functions of proteins in the body.
Proteins are involved in cell turnover, enzyme activity, transportation (e.g., blood cells), hormone production, muscle contraction, and immune functions.
Differentiate between isolate and concentrate protein types.
Isolate protein has no non-protein components, while concentrate protein contains non-protein components.
Explain the difference between complete and incomplete proteins.
Complete proteins contain all or nearly all essential amino acids, while incomplete proteins lack one or more essential amino acids.
What are limiting amino acids and their impact on protein synthesis?
Limiting amino acids are the essential amino acids present in the lowest quantity in food, which can hinder the body’s ability to synthesise proteins if inadequate.
How many branched-chain amino acids are there, and why are they important?
There are three branched-chain amino acids, which are important for muscle metabolism and energy production.
What is the simplest amino acid, and what is its structure?
The simplest amino acid is Glycine, which has a structure consisting of a hydrogen atom as its R group.
Explain the significance of protein quality in nutrition.
Protein quality is important as it determines whether a protein source provides all essential amino acids needed for bodily functions.
What is the PDCAAS and what does it do?
Protein Digestibility Corrected Amino Acid Score evaluates the quality of a protein in food by considering the amino acid profile and how easily the body can digest it.
Explain the DIAAS method
Digestible Indispensable Amino Acid Score evaluates the amount, profile, and digestibility of indispensable amino acids in protein foods.
Why are DIAAS better than PDCAAS?
They provide a more accurate prediction of protein utilisation by humans and allows for ranking protein sources without an upper limit.
Explain the process of amino acid absorption in the human body.
Amino acids are primarily absorbed in the upper small intestine, specifically in the ileum, which is more efficient than absorption in the colon, leading to better utilisation of proteins consumed.
Describe the issues associated with the PDCAAS method.
The PDCAAS method tends to overestimate the digestibility of protein and the delivery of amino acids, which can lead to inaccurate assessments of protein quality.
Describe the role of leucine in muscle protein synthesis (MPS).
Leucine is an amino acid that stimulates muscle protein synthesis (MPS) and is considered the primary driver for muscle hypertrophy.
Explain the concept of the Leucine Threshold.
The Leucine Threshold refers to the minimum amount of leucine required to trigger an increase in muscle protein synthesis, typically around 0.05g per kg of body mass.
How does the amount of protein consumed relate to the MPS threshold for optimal adaptation?
The MPS threshold for optimal adaptation is between 1.7 to 3.5 grams of leucine, indicating that consuming protein within this range is beneficial for muscle growth.
Describe the method used to determine protein quality.
Protein quality should be determined utilising DIAAS (Digestible Indispensable Amino Acid Score).
How does leucine content affect the dosage of protein required for muscle protein synthesis (MPS)?
Proteins higher in leucine content are required in lower doses to stimulate muscle protein synthesis (MPS).
