1- What could happen to a cell if the nucleolus is not functioning properly?
If the nucleolus is not functioning, the cell cannot produce ribosomes e;iciently. Without
ribosomes, protein synthesis slows or stops, since ribosomes are responsible for
translating mRNA into proteins. This failure would a;ect nearly every cellular process, from
enzyme production to structural proteins in the cytoskeleton. Cells might become unable
to grow, repair themselves, or divide. For example, muscle and nerve cells would lose
function due to the lack of proteins needed for contraction or signaling. Over time, the cell
would likely undergo stress and possibly programmed cell death (apoptosis) because it
could not maintain essential processes.
2- Explain how the rough ER and the Golgi apparatus work together in the synthesis and
secretion of proteins. What would happen if this communication between organelles were
disrupted?
The rough ER is studded with ribosomes and produces proteins, especially those destined
for secretion or membranes. These proteins are folded and packaged into vesicles that
travel to the Golgi apparatus. The Golgi acts like a post o;ice, modifying, sorting, and
packaging proteins for their final destinations, whether inside the cell or secreted outside.
If communication between the RER and the Golgi were disrupted, proteins would not be
properly modified or delivered correctly. Misfolded proteins could build up in the ER,
causing stress, while important molecules like hormones or enzymes would not reach their
targets. The result would be serious cellular dysfunction, including reduced secretion,
impaired communication between cells, and even cell death in severe cases.
3- Compare and contrast the roles of lysosomes and proteasomes in cellular waste
management. In what ways are their functions similar, and how do they di;er in terms of
the types of molecules they degrade?
Both lysosomes and proteasomes act as the cell’s recycling centers, but they handle
di;erent types of waste. Lysosomes are membrane-bound vesicles that contain enzymes
capable of breaking down large macromolecules like proteins, lipids, carbohydrates, and
nucleic acids, as well as old organelles. They work like the cell’s “cleaning crew,” digesting
bulk waste and recycling components. Proteasomes, on the other hand, are cylindrical
protein complexes in the cytoplasm and nucleus. They specifically degrade misfolded,
damaged, or unneeded proteins into smaller peptide fragments. Unlike lysosomes,
proteasomes do not digest organelles or large biomolecules. Both systems keep the cell
healthy by preventing waste buildup, but lysosomes handle large-scale degradation while
proteasomes focus on targeted protein quality control. Together, they ensure e;icient
turnover of cellular materials
If the nucleolus is not functioning, the cell cannot produce ribosomes e;iciently. Without
ribosomes, protein synthesis slows or stops, since ribosomes are responsible for
translating mRNA into proteins. This failure would a;ect nearly every cellular process, from
enzyme production to structural proteins in the cytoskeleton. Cells might become unable
to grow, repair themselves, or divide. For example, muscle and nerve cells would lose
function due to the lack of proteins needed for contraction or signaling. Over time, the cell
would likely undergo stress and possibly programmed cell death (apoptosis) because it
could not maintain essential processes.
2- Explain how the rough ER and the Golgi apparatus work together in the synthesis and
secretion of proteins. What would happen if this communication between organelles were
disrupted?
The rough ER is studded with ribosomes and produces proteins, especially those destined
for secretion or membranes. These proteins are folded and packaged into vesicles that
travel to the Golgi apparatus. The Golgi acts like a post o;ice, modifying, sorting, and
packaging proteins for their final destinations, whether inside the cell or secreted outside.
If communication between the RER and the Golgi were disrupted, proteins would not be
properly modified or delivered correctly. Misfolded proteins could build up in the ER,
causing stress, while important molecules like hormones or enzymes would not reach their
targets. The result would be serious cellular dysfunction, including reduced secretion,
impaired communication between cells, and even cell death in severe cases.
3- Compare and contrast the roles of lysosomes and proteasomes in cellular waste
management. In what ways are their functions similar, and how do they di;er in terms of
the types of molecules they degrade?
Both lysosomes and proteasomes act as the cell’s recycling centers, but they handle
di;erent types of waste. Lysosomes are membrane-bound vesicles that contain enzymes
capable of breaking down large macromolecules like proteins, lipids, carbohydrates, and
nucleic acids, as well as old organelles. They work like the cell’s “cleaning crew,” digesting
bulk waste and recycling components. Proteasomes, on the other hand, are cylindrical
protein complexes in the cytoplasm and nucleus. They specifically degrade misfolded,
damaged, or unneeded proteins into smaller peptide fragments. Unlike lysosomes,
proteasomes do not digest organelles or large biomolecules. Both systems keep the cell
healthy by preventing waste buildup, but lysosomes handle large-scale degradation while
proteasomes focus on targeted protein quality control. Together, they ensure e;icient
turnover of cellular materials
