🧬 Biochemistry Solved MCQs with Answers

Practice 1490 approved 🧬 Biochemistry questions with verified answers from the 🧬 Medical Science subject for Pakistan exams.

1490 solved MCQs

According to the fluid mosaic model of cell membranes,Answer: The membrane is a highly mobile mixture of phospholipids and proteins The simplest way to differentiate a prokaryotic cell from a eukaryotic one is toAnswer: See if a nucleus is present Which of the following is the best criterion for deciding whether a cell is prokaryotic or eukaryotic?Answer: The cell has a nucleus or not Lysosomes are specialized vesicles in __________ that contain digestive enzymes for the breakdown of food. A related organalle known as a vacuole, which is found in __________ , also contains enzymes but in addition may act as a storage organelle for nutrients or water.Answer: animals; plants and fungi The highly folded membranes found in such eukaryotic organelles as mitochondria and chloroplastsAnswer: Increase the surface area where key chemical processes can occur Which of the following statements about prokaryotes is false?Answer: The substance known as cytosol is found within the bacterial nucleus What do dystrophin, utrophin, actin, and tubulin have to do with eukaryotic cell structure and function?Answer: They all participate in the production of large amounts of ATP In which of the following cell organelles, it is expected to find the biochemical reactions that harness energy from the breakdown of sugar molecules to synthesize large amounts of ATP?Answer: Mitochondria Which of the following macromolecules are found in the plasma membrane?Answer: Lipids, proteins, and carbohydrates Clearly defined nucleus, mitochondria in a large central vacuole and chloroplasts, indicate the group of organisms fromAnswer: Plants Which of the following are responsible causing the diseases?Answer: Pathogens In which of the following cell types more cellular detail can be observed using an electron microscope compared to a light microscope?Answer: All of the above Which of the following is present in both prokaryotes and eukaryotes?Answer: Plasma membrane When the amino acid alanine (R-group is CH₃) is added to a solution with a pH of 7.3, alanine becomesAnswer: A zwitterions What is the end product of leucine metabolism?Answer: Acetyl-CoA What is the heaviest of the twenty amino acids?Answer: Tryptophan Which of the following amino acids can form hydrogen bonds with their side (R) groups?Answer: All of these The isoelectric point of an amino acid is defined as the pHAnswer: Where the molecule carries no electric charge Molecules that bear charged groups of opposite polarity are known asAnswer: Zwitterions What is the product of the catabolic breakdown of Arginine?Answer: Alpha-ketoglutarate Which amino acids would most likely reside in the membrane-anchoring domain of a membrane embedded protein?Answer: Isoleucine, valine and phenylalanine An essential amino acid is one thatAnswer: The body cannot synthesize D-Alanine and L-Alanine are technically known asAnswer: Enantiomers Which of the following pairs of amino acids would carry a negative charge on their side chain at pH 8.0?Answer: Aspartate & Glutamate In a polypeptide average mass of an amino acid residue isAnswer: 110 daltons Which pair of amino acids absorbs the most UV light at 280 nm?Answer: Trp & Tyrosine Which of the following is a nonstandard amino acid?Answer: Hydroxyproline Which of the following is an essential amino acid?Answer: All of these Protein fluorescence arises primarily from which residue?Answer: Tryptophan Which of the following amino acid is known as half-cystine residue?Answer: Cysteine