Biology · Chemistry

Biomolecules and Enzymes

1,432 Questions

This topic focuses on biomolecules, specifically proteins, enzymes, and amino acids. It includes questions on enzyme structures, protein folding, and catalysis. These concepts are crucial for medical and biology competitive exams.

Enzyme catalysisProtein structuresAmino acid synthesisPolypeptide chainsBiomolecule properties

Biomolecules and Enzymes Questions

Multiple choice
  1. Active Site

  2. Substrate

  3. None of the above

  4. Allosteric Site

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The substrate is the specific reactant molecule that binds to an enzyme's active site, where it undergoes a chemical reaction to be converted into products.

Multiple choice
  1. Carbohydrate

  2. Protein

  3. Lipid

  4. Nucleic Acid

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In biochemical nomenclature, molecules ending with the suffix '-ase' are enzymes (such as lactase, amylase, or helicase). Since enzymes are specialized catalytic proteins, they belong to the protein class of macromolecules.

Multiple choice
  1. Carbohydrate

  2. Protein

  3. Lipid

  4. Nucleic Acid

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In biochemistry, chemical names ending in the suffix '-ose' represent sugars, which are carbohydrates (such as glucose, fructose, and sucrose). Proteins, lipids, and nucleic acids do not follow this naming convention.

Multiple choice
  1. Hydrocarbon chains

  2. Amino acids

  3. mRNA nucleotides

  4. Polypeptide chains

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Protein synthesis links amino acids together via peptide bonds to form polypeptide chains, which then fold into functional proteins. Amino acids are the individual building blocks, not the final product of the synthesis process.

Multiple choice
  1. Elastin

  2. Collagen

  3. Glycoaminoglycan

  4. Chitin

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Elastin is a highly elastic protein in connective tissue that allows many tissues in the body to resume their shape after stretching or contracting. Collagen provides tensile strength rather than rubber-like elasticity, while glycosaminoglycans are carbohydrate chains in the ground substance, and chitin is a structural polysaccharide found in fungi and arthropods.

Multiple choice
  1. Cell adhesion proteins

  2. Enzymes

  3. Digestive proteins

  4. Protein fibers that make up fibrous connective tissue

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fibronectin and laminin are glycoproteins of the extracellular matrix that function as cell adhesion proteins, anchoring cells to the matrix and guiding cell migration. They are not enzymes or digestive proteins, nor do they form the primary structural fibers like collagen or elastin.

Multiple choice
  1. Collagen

  2. Elastin

  3. Enzyme

  4. Gluten

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Gluten is the primary composite protein found in wheat, barley, and rye, giving dough its elasticity and chewiness. Collagen and elastin are structural proteins found in animal tissues, while enzymes are biological catalysts.

Multiple choice
  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mycoprotein, which is the main ingredient in Quorn products, is a fungi-derived protein source used as a meat substitute. It serves as an excellent protein alternative for vegetarians, vegans, and those looking to reduce meat consumption.

Multiple choice
  1. incomplete

  2. complete

  3. complementing

  4. complate

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A complete protein contains all nine essential amino acids that the human body cannot synthesize on its own and must obtain from the diet. Incomplete proteins lack one or more of these essential amino acids.

Multiple choice
  1. complete protein

  2. incomplete protein

  3. complementing protein

  4. totally awesome protein

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Complementing proteins (or complementary proteins) are two or more incomplete protein sources that, when eaten together, compensate for each other's lack of specific essential amino acids to provide a complete protein profile.

Multiple choice
  1. amino acids

  2. fatty acids

  3. monosaccharides

  4. water

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Proteins are polymers made up of long chains of monomeric units called amino acids. Fatty acids are building blocks of lipids, and monosaccharides are building blocks of carbohydrates.

Multiple choice
  1. True

  2. False

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ribosomes are the cellular structures responsible for protein synthesis, translating messenger RNA (mRNA) into polypeptide chains.