.png "MCQs ll AMINO ACIDS ll NEET ll NTA ll ABHYAS")
Amino acids are:
- a) building blocks of carbohydrates
- b) building blocks of nucleic acids
- c) building blocks of lipids
- d) building blocks of proteins
Answer: d) building blocks of proteins
Explanation: Amino acids are the fundamental components that make up proteins. Proteins are essential for various bodily functions, including the formation and repair of tissues.
Amino acids have:
- a) both amino group and carboxyl group
- b) both amino group and keto group
- c) amino group only
- d) carboxyl group only
Answer: a) both amino group and carboxyl group
Explanation: Amino acids contain an amino group (-NH2) and a carboxyl group (-COOH), which are essential for forming peptide bonds in proteins.
The simplest amino acid is:
- a) Proline
- b) Methionine
- c) Glycine
- d) Serine
Answer: c) Glycine
Explanation: Glycine is the simplest amino acid with a single hydrogen atom as its side chain, making it the smallest and most flexible amino acid.
The first amino acid in a polypeptide chain is:
- a) Serine
- b) Valine
- c) Alanine
- d) Methionine
Answer: d) Methionine
Explanation: Methionine is encoded by the start codon (AUG) in mRNA, making it the first amino acid incorporated into a growing polypeptide chain during protein synthesis.
Acidic amino acids include:
- a) Arginine and glutamate
- b) Aspartate and asparagine
- c) Aspartate and lysine
- d) Aspartate and glutamate
Answer: d) Aspartate and glutamate
Explanation: Aspartate and glutamate are acidic amino acids because they have carboxyl groups in their side chains, which release protons and carry a negative charge at physiological pH.
Amino acids with hydroxyl groups are:
- a) Serine and alanine
- b) Alanine and valine
- c) Serine and threonine
- d) Valine and isoleucine
Answer: c) Serine and threonine
Explanation: Serine and threonine have hydroxyl (-OH) groups in their side chains, making them polar and capable of forming hydrogen bonds with water and other molecules.
The 21st amino acid is:
- a) Hydroxy lysine
- b) Hydroxyl proline
- c) Selenocysteine
- d) Citrulline
Answer: c) Selenocysteine
Explanation: Selenocysteine is considered the 21st amino acid and is incorporated into proteins by a unique mechanism involving a specific tRNA and the UGA codon, which usually signals stop.
Which is a phospholipid:
- a) Lecithin
- b) Cholesterol
- c) Sterol
- d) Steroid
Answer: a) Lecithin
Explanation: Lecithin is a phospholipid that plays a critical role in forming cell membranes due to its amphipathic nature, containing both hydrophilic and hydrophobic regions.
Palmitic acid contains:
- a) 20 carbon
- b) 16 carbon
- c) 17 carbon
- d) 15 carbon
Answer: b) 16 carbon
Explanation: Palmitic acid is a saturated fatty acid with a chain of 16 carbon atoms (C16H32O2).
In solutions of different pHs, the structure of amino acids changes due to its:
- a) Ionizable nature
- b) Non-ionizable nature
- c) Crystallisable nature
- d) Non-crystallisable nature
Answer: a) Ionizable nature
Explanation: Amino acids can gain or lose protons depending on the pH of the solution, altering their charge and structure due to the ionizable nature of their amino and carboxyl groups.
Answer: Amino acids are organic compounds that serve as the building blocks of proteins. They contain an amino group, a carboxyl group, and a unique side chain.
2. How many amino acids are there?
Answer: There are 20 standard amino acids that are encoded by the genetic code. Additionally, selenocysteine is known as the 21st amino acid.
3. Why are amino acids important for the body?
Answer: Amino acids are crucial for synthesizing proteins, which are essential for various bodily functions, including enzyme activity, cellular structure, and muscle development.
4. What is the simplest amino acid?
Answer: Glycine is the simplest amino acid, with a hydrogen atom as its side chain.
5. What are acidic amino acids?
Answer: Acidic amino acids, such as aspartate and glutamate, have carboxyl groups in their side chains, which give them a net negative charge at physiological pH.
6. What role does methionine play in protein synthesis?
Answer: Methionine is the first amino acid in the sequence of a newly synthesized polypeptide chain, as it is encoded by the start codon AUG.
7. What is a phospholipid, and why is it important?
Answer: Phospholipids, such as lecithin, are essential components of cell membranes. They have both hydrophilic and hydrophobic regions, allowing them to form lipid bilayers that make up the cell membrane structure.
8. How does pH affect amino acids?
Answer: The structure of amino acids can change with pH due to their ionizable groups. In different pH environments, amino acids can gain or lose protons, affecting their charge and structure.
9. What is the function of selenocysteine?
Answer: Selenocysteine is known as the 21st amino acid and plays a critical role in the function of certain enzymes, especially those involved in redox reactions.
10. What is the carbon count of palmitic acid? - Answer: Palmitic acid is a saturated fatty acid with 16 carbon atoms.
.png&description=MCQs ll AMINO ACIDS ll NEET ll NTA ll ABHYAS){kind=link}
0 Comments