Biol 302, Lecture 10 - Membrane-Enclosed Organelles and Cell Size

This set of flashcards covers the key concepts discussed in Lecture 10 of Biol 302, focusing on membrane-enclosed organelles, cell size, eukaryotic cell structure, protein sorting, and related processes.

What percentage of the cell is made up of membrane-enclosed organelles?

Over half of the cell.

What is the primary function of mitochondria?

ATP synthesis.

What process occurs in chloroplasts?

ATP synthesis and carbon fixation.

What is the function of the endoplasmic reticulum (ER)?

Synthesis of lipids and proteins.

What role does the Golgi apparatus serve?

Modification, sorting, and packaging of proteins/lipids.

What is the significance of surface area to volume ratio in cells?

A smaller cell has a higher surface area to volume ratio, facilitating material exchange.

What distinguishes eukaryotic cells from prokaryotic cells?

Eukaryotic cells have extensive and elaborately arranged internal membranes.

What is required for protein sorting into organelles?

Specific sorting signals.

How do proteins typically enter the endoplasmic reticulum?

From the cytosol still bound to ribosomes.

What do nuclear pores regulate the passage of?

Proteins, RNA, and ribosomes.

What is the function of nuclear localization signals?

To facilitate the transport of proteins into the nucleus.

What encodes proteins for mitochondria and chloroplasts?

Nuclear genes.

What is the function of the signal recognition particle (SRP)?

To facilitate the binding of proteins to the translocation channel in the ER membrane.

What characterizes transmembrane proteins?

They require specific signals and determine their arrangement in the membrane.

What happens during the translocation of soluble proteins?

They are released in the ER lumen and transported to other organelles or secreted.

What happens to signal sequences after protein sorting?

They are usually removed from the finished protein.

What does the term 'intracellular digestion' refer to in the context of organelles?

The function of lysosomes.

What are peroxisomes primarily involved in?

Oxidation of toxic molecules.