Gaokao Biology: Cell Biology and Metabolism Flashcards
7 cards from real GAOKAO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Gaokao Biology: Cell Biology and Metabolism flashcards as text
Which phenomenon demonstrates that the cell membrane is selectively permeable?
Answer: Small nonpolar molecules cross freely while large polar molecules require protein channels
Selective permeability means small nonpolar molecules (O₂, CO₂) pass freely while large or charged molecules (glucose, ions) require specific transport proteins.
During the Krebs cycle, which high-energy electron carrier is produced in the GREATEST quantity per cycle?
Answer: NADH
Each turn of the Krebs cycle produces 3 NADH, 1 FADH₂, 1 GTP/ATP, and 2 CO₂; NADH is produced in the greatest quantity.
What is the role of plastoquinone (PQ) in the photosynthetic electron transport chain?
Answer: It carries electrons from PSII to the cytochrome b6f complex
Plastoquinone is a mobile electron carrier that shuttles electrons and protons from PSII to the cytochrome b6f complex, contributing to the proton gradient across the thylakoid membrane.
The microtubule organizing center (MTOC) in animal cells is called the:
Answer: Centrosome
The centrosome, containing a pair of centrioles and pericentriolar material, nucleates and organizes microtubules including those of the mitotic spindle.
Which of the following enzymes catalyzes the first committed step in glycolysis?
Answer: Phosphofructokinase-1 (PFK-1)
PFK-1 catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate; this is the first irreversible, rate-limiting step committed to glycolysis.
In a cell where mitochondria have been removed, which metabolic process can still proceed?
Answer: Glycolysis
Glycolysis occurs in the cytoplasm and does not require mitochondria; all other listed processes occur in or require mitochondria.
Which of the following correctly describes the relationship between photosynthesis and cellular respiration in a plant cell?
Answer: Both occur simultaneously; respiration uses some of the glucose produced by photosynthesis
Both processes occur simultaneously in plant cells; during the day, photosynthesis exceeds respiration and the plant has a net CO₂ uptake.