This question tests knowledge of basic carbohydrate chemistry, specifically the composition of common disaccharides. Sucrose is a disaccharide, meaning it is formed from two monosaccharide units joined together.
Correct Option: B) Sucrose is a disaccharide composed of one molecule of glucose and one molecule of fructose linked together.
The question asks to identify the two main components that make up starch, which is a polysaccharide. We need to recall the composition of starch from biochemistry or biology.
D) Amylose and amylopectin — Starch is indeed a mixture of these two polysaccharides. Amylose is a linear polymer of glucose, while amylopectin is a branched polymer of glucose. Both are crucial components of starch.
The Respiratory Quotient (RQ) is a ratio used in biology to determine the type of substrate being metabolized for energy. It is calculated by dividing the volume of carbon dioxide produced by the volume of oxygen consumed during respiration. We need to recall the general chemical equation for carbohydrate respiration and apply the RQ formula.
Define Respiratory Quotient (RQ): The RQ is defined as the ratio of the volume of carbon dioxide (\(CO_2\)) produced to the volume of oxygen (\(O_2\)) consumed during respiration.
\[ RQ = \frac{\text{Volume of } CO_2 \text{ produced}}{\text{Volume of } O_2 \text{ consumed}} \]Consider the respiration of carbohydrates: A common carbohydrate used in respiration is glucose (\(C_6H_{12}O_6\)). The balanced chemical equation for the complete aerobic respiration of glucose is:
\[ C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{Energy} \]Identify volumes of \(CO_2\) and \(O_2\): From the balanced equation, we can see that for every 6 molecules (or volumes) of \(O_2\) consumed, 6 molecules (or volumes) of \(CO_2\) are produced.
Calculate the RQ for carbohydrates: Substitute these values into the RQ formula:
\[ RQ = \frac{6 \text{ volumes of } CO_2}{6 \text{ volumes of } O_2} = 1.0 \]Correct Option: B) 1.0 — The Respiratory Quotient for carbohydrates is 1.0 because, during their complete aerobic oxidation, the volume of carbon dioxide produced is equal to the volume of oxygen consumed.
The question asks to identify the carbohydrate that is found exclusively in milk. This requires knowledge of common carbohydrates and their natural sources.
Correct Option: D) Lactose is a disaccharide composed of glucose and galactose. It is commonly known as "milk sugar" because it is found almost exclusively in milk and dairy products. It is synthesized in the mammary glands of mammals.
This question asks to identify the basic building blocks (monomers) of proteins. Understanding the fundamental composition of macromolecules is crucial in biology and biochemistry.
Correct Option: D) Amino acids are the monomers that link together to form proteins. There are 20 common types of amino acids that combine in various sequences to create the vast diversity of proteins found in living organisms.
The question asks to identify the correct definition of essential amino acids. We need to recall the classification of amino acids based on the body's ability to synthesize them.
B) Cannot be synthesised by the human body and must be obtained from diet
This statement accurately defines essential amino acids. The body lacks the biochemical pathways to produce these amino acids, making dietary intake crucial for proper protein synthesis and overall health.