Basic Biochemistry
Biochemistry · Topic 1
Source: NMC CBME Curriculum 2024 · Volume I · Biochemistry · Topic 1 · combined PDF page 162
Practice questions
- Which arrangement of amphipathic membrane lipids is most consistent with a membrane separating the cytosol from an aqueous extracellular environment?
- A membrane is placed between two aqueous solutions. Which feature of its lipid components best explains formation of a bilayer rather than a uniformly mixed arrangement?
- A membrane's hydrophobic interior most directly contributes to which general cellular property?
- A cell-surface protein binds an extracellular ligand and initiates a cellular response. Which membrane-associated role is illustrated most directly?
- A molecule must cross the cell surface by a specific transport mechanism. Which membrane component is the most plausible direct mediator?
- A cell-surface protein has a normal ligand-binding domain but is mistakenly retained away from the cell surface. Which defect best explains failure of its surface receptor function?
- Which statement best describes the possible molecular attachment of cell-surface carbohydrates?
- Two cell-surface carbohydrate chains differ in their branching and linkage positions despite containing similar monosaccharides. Which conclusion is best supported?
- Which set contains only structural features that can contribute to the diversity of cell-surface oligosaccharides?
- A carbohydrate detected at the cell surface is covalently associated with a lipid rather than a protein. Which category best fits this mode of presentation?
- Which observation is most characteristic of ABH-related glycosphingolipids in human tissues?
- A laboratory compares cell-surface carbohydrate profiles from two tissues and finds different ABH-related glycosphingolipid expression. Which interpretation is most appropriate?
- Why can tissue-specific expression of blood-group-related glycosphingolipids matter clinically?
- Which statement correctly distinguishes a glycosphingolipid from a glycoprotein as a carrier of a cell-surface carbohydrate?
- A microbial product from the intestinal lumen activates TLR4 and is followed by cytokine and chemokine production. Which product best fits this description?
- LPS is described as a constituent of which type of bacterial membrane?
- Which receptor specifically mediates the innate signaling response to LPS described in the evidence?
- A patient has exposure to bacterial LPS. Which downstream response is most consistent with the described TLR4 pathway?
- A commensal microbial product in the gut triggers a host response through TLR4. Which interpretation best reflects the physiological context of gut LPS?
- Which sequence best represents the general pathway linking bacterial LPS to an immune response?
- A cell-surface protein is synthesized but must be delivered to the appropriate cellular location to function as a receptor. Which broad process most directly governs this delivery?
- A newly synthesized protein reaches the cell surface but has an altered conformation that prevents ligand binding. Which general principle best explains the functional defect?
- A membrane-associated protein undergoes a post-translational change that alters its cellular handling. Which broad molecular process category includes such changes?
- A radiotracer accumulates in a tissue because it interacts with a specific cell-surface receptor. Which molecular event most directly explains selective recognition?
- An experimental inhibitor blocks a cell-surface transporter but leaves a ligand-binding receptor intact. Which outcome is most directly expected?
- A mutation changes the localization of a membrane protein but leaves its amino-acid sequence and ligand-binding region unchanged. What is the most likely functional consequence?
- A cell surface contains both carbohydrate-bearing proteins and carbohydrate-bearing lipids. Which conclusion follows from this observation?
- A gut tissue exhibits an inflammatory response after exposure to microbial LPS. Which conclusion is best supported by the described biology?
- Which combination correctly pairs a cell-surface component with a function or property supported by basic membrane biochemistry?
- A surface assay detects different carbohydrate structures on two cell populations. Which explanation is most directly supported by the known sources of cell-surface oligosaccharide diversity?
- Which statement best integrates the roles of membrane proteins and cell-surface carbohydrates in the organization of a cell boundary?