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Give a detailed account of protein and refer to: • how a peptide bond is formed • essential and non-essential amino acids • supplementary value/complementary role - Leaving Cert Home Economics - Question b - 2020
Question b
Give a detailed account of protein and refer to: • how a peptide bond is formed • essential and non-essential amino acids • supplementary value/complementary role... show full transcript
Worked Solution & Example Answer:Give a detailed account of protein and refer to: • how a peptide bond is formed • essential and non-essential amino acids • supplementary value/complementary role - Leaving Cert Home Economics - Question b - 2020
Step 1
how a peptide bond is formed
Answer
A peptide bond is formed through a process known as condensation. During this reaction, the carboxyl group (-COOH) of one amino acid reacts with the amino group (-NH2) of another amino acid. This results in the elimination of a water molecule. Specifically, the hydroxyl (–OH) from the carboxyl group and a hydrogen atom (H) from the amino group are released, allowing the two amino acids to bond together. Therefore, a peptide bond can be described as:
Step 2
essential and non-essential amino acids
Answer
Amino acids are the building blocks of proteins and can be categorized as essential or non-essential.
- Essential Amino Acids: These cannot be synthesized by the body and must be obtained from the diet. Examples include leucin, lysine, methionine, and phenylalanine.
- Non-Essential Amino Acids: These can be produced by the body and are not required to be consumed through food sources. Examples include alanine, aspartic acid, and glutamic acid. It is crucial for a balanced diet to include both types to support bodily functions.
Step 3
supplementary value/complementary role
Answer
The supplementary value or complementary role of proteins refers to the ability of different protein sources to combine and provide a complete amino acid profile. For instance, when certain plant-based proteins are consumed together (like legumes and grains), they can compensate for each other's deficiencies in essential amino acids. An important consideration is that some food combinations can enhance nutritional value, particularly for those who rely on vegetarian or vegan diets.
Step 4
gel formation
Answer
Gel formation occurs when proteins denature and rearrange into a network that traps water molecules. For example, when collagen is heated, it converts to gelatin, which can absorb large amounts of water. This process is crucial in culinary applications, such as in making jellies or aspics, where the gelatin serves as a setting agent. The ability of proteins to gel is utilized in various dishes like mousse, jellies, and desserts.
Step 5
foam formation
Answer
Foam formation involves the whisking of proteins, particularly egg whites, which unfold and trap air bubbles. This process is essential in creating stable foams that contribute to the texture and volume of various culinary products. For instance, when egg whites are whisked to peaks, they expand significantly; this property is utilized in meringues and soufflés. The whipped mixture can later be set into permanent forms for culinary applications, offering lightness and structure to cakes and mousses.