Biomolecules MCQs

Which of the following statements regarding Isomerases, Ligases, and bond cleavage mechanisms are correct?

I. Isomerases include all enzymes catalyzing inter-conversion of optical, geometric, or positional isomers.
II. Ligases catalyze the linking together of two compounds by joining C-O, C-S, C-N, or P-O bonds.
III. Hydrolysis of ester, glycosidic, and peptide bonds is catalyzed by Lyases.
IV. Enzymes are classified into groups based on the type of reactions they catalyze.

Which of the above statements are correct?

Which of the following statements regarding enzyme co-factors and prosthetic groups are correct?

I. Non-protein constituents bound to enzymes that render them catalytically active are called co-factors, while the protein portion is called the apoenzyme.
II. Prosthetic groups are organic compounds distinguished by being tightly bound to the apoenzyme.
III. In peroxidase and catalase, haem is the prosthetic group present at the active site.
IV. Peroxidase and catalase catalyze the reduction of water and oxygen into hydrogen peroxide.

Which of the above statements are correct?

Which of the following statements regarding co-enzymes and metal ion co-factors are correct?

I. Co-enzymes are organic compounds whose association with the apoenzyme is transient, occurring during catalysis.
II. Many co-enzymes contain essential vitamins, such as niacin present in NAD and NADP.
III. Zinc is a metal ion co-factor required for the proteolytic enzyme carboxypeptidase.
IV. When a co-factor is removed from an enzyme, its catalytic activity increases twofold.

Which of the above statements are correct?

Which of the following statements regarding metabolic pathways and respiration variations are correct?

I. A multistep chemical reaction where each step is catalyzed by specific enzymes is called a metabolic pathway.
II. Conversion of glucose to pyruvic acid during glycolysis involves ten different enzyme-catalyzed reactions.
III. In human skeletal muscle under anaerobic conditions, glycolysis leads to the formation of lactic acid.
IV. Under anaerobic conditions in yeast during fermentation, pyruvic acid is converted directly into glycogen.

Which of the above statements are correct?

Which of the following statements regarding nitrogenous bases, nucleosides, and nucleotides are correct?

I. Adenine and Guanine are purine nitrogenous bases possessing heterocyclic rings.
II. Adenosine and Guanosine are nucleotides containing phosphate groups esterified to pentose sugar.
III. Adenylic acid, Thymidylic acid, and Guanylic acid are nucleotides.
IV. Nucleic acids like DNA and RNA are polymers composed entirely of nucleotides.

Which of the above statements are correct?

Which of the following statements regarding the acid-soluble pool and acid-insoluble fraction are correct?

I. The acid-soluble pool represents roughly the cytoplasmic composition of living tissues.
II. Macromolecules derived from the cytoplasm and organelles constitute the acid-insoluble fraction.
III. Lipids belong to the acid-soluble pool because their molecular weight is strictly above 10,000 Daltons.
IV. The acid-soluble pool contains organic compounds with molecular weights ranging from 18 to around 800 Daltons.

Which of the above statements are correct?

Which of the following statements regarding amino acid zwitterionic behavior and functional groups are correct?

I. Amino acids are called α-amino acids because the amino group and carboxyl group are attached to the same α-carbon.
II. Alanine contains a hydroxy methyl group (-CH₂OH) as its variable R group.
III. Tyrosine, phenylalanine, and tryptophan are aromatic amino acids.
IV. Due to the ionizable nature of -NH₂ and -COOH groups, the structure of amino acids changes in solutions of different pH.

Which of the above statements are correct?

Which of the following statements regarding fatty acids, glycerides, and oils are correct?

I. Fatty acids possess a carboxyl group attached to an R group containing 1 to 19 carbons.
II. Palmitic acid has 16 carbon atoms excluding the carboxyl carbon.
III. Unsaturated fatty acids contain one or more C=C double bonds.
IV. Oils have lower melting points than fats (e.g., gingelly oil) and remain as liquids in winter.

Which of the above statements are correct?

Which of the following statements regarding phospholipids and cell membrane components are correct?

I. Lecithin is an example of a phospholipid containing a phosphorylated organic compound.
II. Phospholipids are fundamental structural components of cell membranes.
III. Neural tissues contain lipids with particularly complex structures.
IV. Phospholipids are true polymeric macromolecules with molecular weights exceeding 10,000 Daltons.

Which of the above statements are correct?

Which of the following statements regarding nitrogenous bases, nucleosides, and nucleotides are correct?

I. Adenine and Guanine are substituted purines, whereas Cytosine, Uracil, and Thymine are substituted pyrimidines.
II. Adenosine, Guanosine, Thymidine, Uridine, and Cytidine are nucleosides.
III. Adenylic acid, Thymidylic acid, and Guanylic acid are nucleotides.
IV. Uracil is the nitrogenous base present exclusively in DNA, while Thymine is present in RNA.

Which of the above statements are correct?