Biology Cell Structure & Function Flashcards

Which organelle is responsible for modifying, sorting, and packaging proteins for secretion?

Answer: Golgi apparatus

The Golgi apparatus receives proteins from the ER, modifies them, and packages them into vesicles for transport or secretion.

What is the primary function of lysosomes?

Answer: Digesting cellular waste and foreign material

Lysosomes contain hydrolytic enzymes that break down macromolecules, old organelles, and pathogens in a process called autophagy or phagocytosis.

Which cytoskeletal component is primarily responsible for cell shape and resisting compression?

Answer: Microtubules

Microtubules are hollow tubes made of tubulin that provide structural support, maintain cell shape, and form tracks for organelle transport.

What distinguishes smooth endoplasmic reticulum from rough endoplasmic reticulum?

Answer: Smooth ER lacks ribosomes; rough ER has ribosomes on its surface

Rough ER has ribosomes attached to its cytoplasmic surface for protein synthesis, while smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.

In which part of a eukaryotic cell does translation occur?

Answer: Ribosomes in the cytoplasm and on rough ER

Translation (protein synthesis) occurs at ribosomes, which can be free in the cytoplasm or attached to the rough endoplasmic reticulum.

What is the role of the centrosome in animal cells?

Answer: Organizing the mitotic spindle during cell division

The centrosome, containing a pair of centrioles, is the main microtubule-organizing center and nucleates spindle fibers during mitosis.

Which feature of the plasma membrane allows it to be selectively permeable?

Answer: The phospholipid bilayer with embedded proteins

The phospholipid bilayer's hydrophobic core blocks most polar molecules, while embedded transport proteins selectively allow specific substances to cross.