MCAT Chem Domain 5: Biology Welcome to your MCAT Chem Domain 5: Biology 1. MCAT Chem: Biology During glycolysis, the step that involves the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate is catalyzed by which enzyme? Hexokinase Phosphofructokinase Glyceraldehyde-3-phosphate dehydrogenase Pyruvate kinase None 2. MCAT Chem: Biology In the context of molecular biology, which enzyme is responsible for unwinding the DNA double helix during replication? DNA polymerase Helicase Ligase Topoisomerase None 3. MCAT Chem: Biology The Lineweaver-Burk plot is used to determine which of the following? The efficiency of substrate utilization by an enzyme The change in Gibbs free energy for a reaction The maximum velocity (Vmax) and Michaelis constant (Km) of an enzyme-catalyzed reaction The pH optimum for enzyme activity None 4. MCAT Chem: Biology Which of the following statements accurately describes the function of the sodium-potassium pump in neuronal cells? It pumps sodium ions into the cell and potassium ions out of the cell, utilizing ATP. It allows passive diffusion of sodium and potassium ions across the membrane without energy expenditure. It pumps sodium ions out of the cell and potassium ions into the cell, utilizing ATP. It exchanges sodium ions for calcium ions without the use of ATP. None 5. MCAT Chem: Biology What is the primary structure of a protein determined by? The sequence of amino acids Hydrogen bonding between amino acid residues Disulfide bonds between cysteine residues Hydrophobic interactions between side chains None 6. MCAT Chem: Biology Ribozymes are characterized by their ability to: Store genetic information in cells. Catalyze chemical reactions without proteins. Transport oxygen in the bloodstream. Act as membrane receptors. None 7. MCAT Chem: Biology In eukaryotic cells, transcription occurs in the: Cytoplasm. Mitochondria. Nucleus. Endoplasmic reticulum. None 8. MCAT Chem: Biology The tertiary structure of a protein is primarily stabilized by: Peptide bonds between amino acids. The sequence of nucleotides in DNA. Non-covalent interactions such as hydrogen bonds, ionic bonds, and hydrophobic interactions. Covalent bonds between nucleotides. None 9. MCAT Chem: Biology The process of forming mRNA from DNA is known as: Translation Transcription Replication Mitosis None 10. MCAT Chem: Biology Which process describes the movement of substances against their concentration gradient with the expenditure of energy? Osmosis Diffusion Active transport Facilitated diffusion None 1 out of 10 Time is Up! Time's up
