Binghamton BIOL 311 Exam 3 Test
Questions and All Actual Answers
2025-2026 Updated.
Lysosomes - Answer Membrane bound organelles with roles involving the
degrading/recycling of cellular waste, cellular signaling, and energy metabolism. Contain 40+
hydrolytic enzymes with optimum pH of 5.0 (acidic). Organelle that stains positively with acid
phosphate (marker enzyme).
Christian de Duve - Answer Discovered lysosomes with differential centrifugation. Results
ended with a pellet. Intact pellets showed respiratory (mitochondrial) activity, while "injured"
pellets showed respiratory and hydrolytic (lysosomal) activity.
Lysosome organization and function - Answer Autophagy, heterophagy, and specialized
Autophagy - Answer A process in which lysosomes decompose damaged organelles to reuse
their organic monomers. (Break down of damaged organelles; "self eating").
Heterophagy - Answer Phagocytosis; process of lysosomal digestion of materials ingested
from the extracellular environment ("eating others").
Specialized lysosomes - Answer Acrosomes (sperm cells; differentiated lysosomes), plant
vacuoles.
Examples of heterophagy - Answer WBCs engulfing antigens and RBCs; Semliki Forest Virus
(SFV) infects, binds to LDL receptor, goes into lysosome, and lysosome facilitates (helps) SFV
infection (SFV will bind to LDL receptors and go to CURL)
Chloroquine - Answer Can inhibit the activity of lysosomes that's critical heterophagy and
autophagy. Increases pH from 5.0 to 7.0. May sensitive cancer cells to chemo agents but can
also harm normal cells.
Rudolph Virchow (heterophagy) - Answer Studied blood cells through microscope; observed
WBCs "give birth" to RBCs (WRONG)
Elie Metchnikoff (heterophagy) - Answer Discovered phagocytes - phagon = eat; kytos =
cavity. Thought phagocytes were responsible for aging (WRONG) and gray hair. Conclusion -
WBCs are protective, others weren't and would spread disease.
, Phagocytosis - Answer "Cell eating"; ingestion of bacteria or other material by phagocytes. 1)
Opsonization - coating of bacteria to be eliminated by phagocytes and 2) Leukocytes that bind
to Fc region via the Fc receptor
Phagocytes - Answer A type of white blood cell that ingests invading microbes
Myasthenia gravis - Answer Neuromuscular disease characterized by muscle weakness;
results from lack of ACH receptors in neuromuscular junction. Antibodies group receptors
together.
Dan Drachman - Answer Discovered that patients with Myasthenia Gravis had cells with less
binding to 3H-alpha-bungarotoxin, which binds to ACH-R (R = receptors)
Torpedo Ray - Answer Have highest concentration of ACH-R; ACH-R purified and created
mAbs, when injected into animals, myasthenia gravis symptoms were displayed. Discovery = MG
is autoimmune.
Silicosis (miner's disease) - Answer lysosome attack silica (sharp) and cells leak; causes cell
death (lung tissue) leading to decrease in O2 and CO2 exchange. Fibrosis in tissues (lungs, liver).
Fibrosis - Answer synthesis of new collagen exceeds degradation rate; thickening and
scarring of connective tissue
Lysosomes and human diseases (environmental/non-hereditary) - Answer silicosis (miner's
disease), chloroquine myopathy
Lysosomes and human diseases (hereditary) - Answer lysosomal storage disease, Tay Sachs
disease, Hurler's disease, I cell disease (I = inclusion), Gaucher's disease, Pompe's disease.
Chloroquine myopathy - Answer Used to treat rheumatoid arthritis (RA); bad idea; isolated
incident.
Tay-Sachs disease - Answer Accumulation of glycosaminoglycans, deficiency in
hexosaminidase A; children die at birth
Hurler's disease - Answer "Gargoylism": Missing enzyme is a-l-iduronidase - airway
obstruction, corneal clouding, recurrent ear infections/hearing loss; early death. Hurler cells and
normal cells will become same normal size. CAN BE CORRECTED WITH STEM CELLS
Questions and All Actual Answers
2025-2026 Updated.
Lysosomes - Answer Membrane bound organelles with roles involving the
degrading/recycling of cellular waste, cellular signaling, and energy metabolism. Contain 40+
hydrolytic enzymes with optimum pH of 5.0 (acidic). Organelle that stains positively with acid
phosphate (marker enzyme).
Christian de Duve - Answer Discovered lysosomes with differential centrifugation. Results
ended with a pellet. Intact pellets showed respiratory (mitochondrial) activity, while "injured"
pellets showed respiratory and hydrolytic (lysosomal) activity.
Lysosome organization and function - Answer Autophagy, heterophagy, and specialized
Autophagy - Answer A process in which lysosomes decompose damaged organelles to reuse
their organic monomers. (Break down of damaged organelles; "self eating").
Heterophagy - Answer Phagocytosis; process of lysosomal digestion of materials ingested
from the extracellular environment ("eating others").
Specialized lysosomes - Answer Acrosomes (sperm cells; differentiated lysosomes), plant
vacuoles.
Examples of heterophagy - Answer WBCs engulfing antigens and RBCs; Semliki Forest Virus
(SFV) infects, binds to LDL receptor, goes into lysosome, and lysosome facilitates (helps) SFV
infection (SFV will bind to LDL receptors and go to CURL)
Chloroquine - Answer Can inhibit the activity of lysosomes that's critical heterophagy and
autophagy. Increases pH from 5.0 to 7.0. May sensitive cancer cells to chemo agents but can
also harm normal cells.
Rudolph Virchow (heterophagy) - Answer Studied blood cells through microscope; observed
WBCs "give birth" to RBCs (WRONG)
Elie Metchnikoff (heterophagy) - Answer Discovered phagocytes - phagon = eat; kytos =
cavity. Thought phagocytes were responsible for aging (WRONG) and gray hair. Conclusion -
WBCs are protective, others weren't and would spread disease.
, Phagocytosis - Answer "Cell eating"; ingestion of bacteria or other material by phagocytes. 1)
Opsonization - coating of bacteria to be eliminated by phagocytes and 2) Leukocytes that bind
to Fc region via the Fc receptor
Phagocytes - Answer A type of white blood cell that ingests invading microbes
Myasthenia gravis - Answer Neuromuscular disease characterized by muscle weakness;
results from lack of ACH receptors in neuromuscular junction. Antibodies group receptors
together.
Dan Drachman - Answer Discovered that patients with Myasthenia Gravis had cells with less
binding to 3H-alpha-bungarotoxin, which binds to ACH-R (R = receptors)
Torpedo Ray - Answer Have highest concentration of ACH-R; ACH-R purified and created
mAbs, when injected into animals, myasthenia gravis symptoms were displayed. Discovery = MG
is autoimmune.
Silicosis (miner's disease) - Answer lysosome attack silica (sharp) and cells leak; causes cell
death (lung tissue) leading to decrease in O2 and CO2 exchange. Fibrosis in tissues (lungs, liver).
Fibrosis - Answer synthesis of new collagen exceeds degradation rate; thickening and
scarring of connective tissue
Lysosomes and human diseases (environmental/non-hereditary) - Answer silicosis (miner's
disease), chloroquine myopathy
Lysosomes and human diseases (hereditary) - Answer lysosomal storage disease, Tay Sachs
disease, Hurler's disease, I cell disease (I = inclusion), Gaucher's disease, Pompe's disease.
Chloroquine myopathy - Answer Used to treat rheumatoid arthritis (RA); bad idea; isolated
incident.
Tay-Sachs disease - Answer Accumulation of glycosaminoglycans, deficiency in
hexosaminidase A; children die at birth
Hurler's disease - Answer "Gargoylism": Missing enzyme is a-l-iduronidase - airway
obstruction, corneal clouding, recurrent ear infections/hearing loss; early death. Hurler cells and
normal cells will become same normal size. CAN BE CORRECTED WITH STEM CELLS
