Cell Organelles and Their Functions

Flashcards reviewing lecture notes on cell organelles and their functions.

Endoplasmic Reticulum (ER)

A network of branching tubules and sacs connected to the outer membrane of the nuclear envelope, creating a continuous compartment called the ER lumen.

Rough ER

Part of the ER covered with ribosomes.

Smooth ER

Part of the ER without ribosomes.

Smooth ER Functions

Functions include intracellular Ca2+ storage and lipid synthesis.

Rough ER Functions

Serves as the "port of entrance" of the secretory pathway, synthesizing and folding proteins, performing protein glycosylation, forming disulfide bonds and assembling multisubunit proteins.

Golgi Apparatus

A collection of flattened, membrane-enclosed compartments called cisternae, located close to the nucleus in animal cells.

Golgi Functions

Sorting of proteins that are part of the secretory pathway and protein glycosylation.

Lysosome Functions

Intracellular digestion of material imported from outside the cell and obsolete cell parts (autophagy).

Peroxisomes

Spherical organelles containing enzymes that use O2 in oxidation reactions, producing H2O2.

Peroxisome Functions

Breakdown of long fatty acid molecules and synthesis of cholesterol; participate in the glyoxylate cycle in plant cells to transform fatty acids into sugars.

Mitochondria

Tubular networks, double membrane organelles containing their own genome, involved in ATP synthesis, source of NAD+, membrane and heme group biosynthesis and Ca2+ reservoir.

Mitochondria Functions

ATP synthesis, Source of NAD+ for metabolic reactions, Membrane biosynthesis, more specifically Phosphatidyl- ethanolamine (PtdEtn), Heme group biosynthesis and Ca2+ reservoir

Chloroplast Functions

Consume ATP to fix carbon and generates saccharides; chlorophyl capture light that is essential for this process and oxygen is produced.

Vacuole Functions

Adjust cell size and internal hydrostatic pressure (turgor pressure), storage of nutrients and metabolites, and degradation of macromolecules.

Nucleus

Surrounded by a nuclear envelope that consists of two concentric membranes, contains the nuclear lamina, and communicates with the cytosol via nuclear pore complexes.