Organelles and Compartmentalization Flashcards

Flashcards about cell organelles and compartmentalization.

Organelle

A discrete structure within a cell adapted to perform a specific function.

Solid organelles

Ribosomes, cytoskeleton components (microtubules, microfilaments).

Single membrane-bound organelles

Lysosomes, peroxisomes, endoplasmic reticulum, Golgi apparatus, vesicles, vacuoles.

Double membrane-bound organelles

Nucleus, mitochondria, chloroplasts.

Ultracentrifugation

A technique involving high-speed spinning to separate particles in a solution based on size, shape, density, and viscosity.

Cell fractionation

A technique to isolate cells, organelles, and other biomolecules.

Benefit of separating nucleus and cytoplasm

Protects DNA from enzymatic degradation and separates transcription from translation.

Post-transcriptional modification

mRNA modification before it leaves the nucleus and is used during translation.

Compartmentalization

Formation of membrane-bound organelles that create separate environments within a cell.

Lysosomes

Contain hydrolytic enzymes that break down macromolecules within a membrane.

Acid hydrolases

Enzymes in lysosomes which work at an optimal pH of about 5.

Phagocytic vacuoles (phagosome)

Isolate engulfed particles (e.g., pathogens) before digestion.

Mitochondrion Outer membrane

Separates the mitochondrion from the cytoplasm.

Mitochondrion Inner membrane

Contains enzymes for oxidative phosphorylation (formation of ATP).

Mitochondrion Intermembrane space

Accumulates protons for chemiosmosis (formation of ATP).

Mitochondrion Cristae

Folds increase surface area for ATP production.

Mitochondrion Matrix

Contains enzymes for the Krebs cycle.

Chloroplast Double membrane

Provides compartmentalization.

Chloroplast Thylakoid membrane

Contains chlorophyll and electron transport proteins (needed for photosynthesis).

Chloroplast Photosystems

Capture light energy for the light-dependent reactions.

Chloroplast Stroma

Contains enzymes for the Calvin cycle.

Nuclear envelope

A double membrane with nuclear pores that allows selective transport.

Nuclear pores

Allow selective transport of RNA, proteins, and signaling molecules.

Ribosomes

Composed of ribosomal RNA and proteins, consist of a small and large subunit.

Free ribosomes

Build proteins used within the cell (floating in the cytoplasm).

Bound ribosomes

Build proteins transported out of the cell or used as integral membrane proteins (attached to the rough ER).

Endomembrane system

Compartmentalized sacs of membrane working together to produce, modify, process, and transport molecules.

Golgi apparatus

Modifies, sorts, and packages proteins and lipids; adds carbohydrate groups to form glycoproteins.

Cis face

The receiving side of the Golgi apparatus, generally convex and facing the nucleus.

Secretory vesicles

Pinch off the Golgi and move throughout the cell to various destinations

Vesicles

Move substances within the cell, carry materials for exocytosis, and lysosomes contain digestive enzymes for breakdown.

Clathrin

Creates a coat that helps phospholipids create a rounded shape as a vesicle forms.