Cell Structure & Organelles
Which organelle is the primary site of ATP synthesis in eukaryotic cells?
Mitochondrion
Cholesterol enters cells via what process?
Receptor-mediated endocytosis
A drug used for weight loss prevents fat digestion by binding to the active site of pancreatic lipase. What type of inhibition does this represent?
Competitive inhibitor
In glycolysis and cellular respiration, what is oxidized and what is reduced?
Glucose is oxidized; oxygen is reduced
In photosynthesis, what molecule is oxidized and what is reduced?
Water is oxidized; CO₂ is reduced
Which plant cell organelle does NOT contain its own DNA and ribosomes?
Vacuole
White blood cells engulf bacteria through what process?
Phagocytosis
How do enzymes affect reaction rate?
They lower activation energy, increasing rate
What is the product of pyruvate oxidation that enters the Krebs cycle?
Acetyl-CoA
Which are products of the light reactions?
ATP, NADPH, O₂
Which structure would be found in both Elodea and liver cells but not in bacteria?
Mitochondria
Water moves through the membrane because of what structure?
Aquaporins
What happens to ΔG if you double enzyme amount?
It stays the same
What causes soreness when muscles run out of oxygen?
Lactic acid fermentation
What must be regenerated to complete the Calvin cycle?
RuBP
Tay-Sachs disease results from a lack of Hexaminidase A. Which organelle is affected?
Lysosome
Large antibodies from breast milk enter infant cells by what process?
Endocytosis
Catabolic reactions do what?
Break down polymers into monomers
Why do wine fermentation tanks need pressure-release valves?
CO₂ builds up during alcohol fermentation
Why do C₄ plants have no photorespiration?
They use PEP carboxylase to fix CO₂
“Lorenzo’s Oil” disease involves incomplete fatty acid breakdown. Which organelle malfunctions?
Peroxisome
Which molecule moves most easily through the phospholipid bilayer by diffusion?
Carbon dioxide
What happens to most enzymes at 41°C fever?
They begin to denature
Which three processes occur during the Krebs cycle?
NADH forms, CO₂ released, Acetyl-CoA combines with oxaloacetate
If a pigment moves 40 mm while the solvent front moves 80 mm, what is its Rf value?
0.5