Chapter 6 Reading Guide: A Tour of the Cell

Vocabulary flashcards covering cellular structures, the endomembrane system, energy-converting organelles, the cytoskeleton, and extracellular components from Chapter 6: A Tour of the Cell.

Nuclear envelope

A structure enclosing the nucleus consisting of $2$ layers (inner and outer membrane) connected by nuclear pores.

Chromatin

The material found within the nucleus composed of DNA and proteins that condenses to form distinct chromosomes as the cell prepares to divide.

Nucleoli

Structures visible when the nucleus does not divide where ribosomes are assembled through rRNA subunits.

Free ribosomes

Ribosomes located in the cytosol that synthesize products such as enzyme catalysts for sugar.

Bound ribosomes

Ribosomes attached to the outside of the endoplasmic reticulum or nuclear envelope that produce proteins for insertion into membranes.

Endomembrane system

A cellular system that regulates protein traffic and performs metabolic functions, consisting of the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, various vesicles and vacuoles, and the plasma membrane.

Smooth ER

An organelle responsible for lipid synthesis (oils, steroids, new membrane phospholipids), calcium ion storage, and drug and poison detoxification by adding hydroxyl groups.

Rough ER

A membrane factory for the cell that packages secretory proteins into transport vesicles and expands by adding membrane proteins and phospholipids to its own membrane.

Cis face (Golgi apparatus)

The region of the Golgi apparatus where transport vesicles budding from the ER fuse to add their membrane and lumen contents.

Lysosome

A membranous sac of hydrolytic enzymes with an acidic pH of $0-6$.

Food vacuoles

Vacuoles formed by phagocytosis that fuse with lysosomes for enzymatic digestion of food.

Contractile vacuoles

Vacuoles that pump excess water out of the cell.

Central vacuole

A plant organelle that absorbs water, plays a major role in plant cell growth, and confines the cytosol to a thin layer against the plasma membrane.

Mitochondria

Organelles that convert nutrients into energy/ATP, featuring a folded inner membrane that divides the interior into an intermembrane space and mitochondrial matrix.

Chloroplasts

Organelles that convert solar energy to chemical energy using individual thylakoid membranes.

Peroxisomes

Organelles that remove hydrogen atoms from various substrates and transfer them to oxygen, producing hydrogen peroxide.

Cytoskeleton

A network of fibers extending throughout the cytoplasm that provides mechanical support, gives structural support, and allows for cell motility.

Cytoskeletal fibers

The three main fiber types composing the cytoskeleton: microtubules, microfilaments, and intermediate filaments.

Centrosome

Structures referred to as compression-resisting girders that contain a pair of centrioles in animal cells.

Centrioles

Paired organelles in animal cells that help organize microtubule assembly.

Cilia

Locomotive cellular appendages characterized by alternating power and recovery strokes.

Flagella

Cellular appendages that move with an undulating motion like the tail of a fish.

Cell wall

A plant cell layer composed of cellulose embedded in saccharides and proteins that protects the cell, maintains its shape, and prevents excessive uptake of water.

Intercellular junctions (Plant cells)

Connections between neighboring plant cells that permit the passage of water, nutrients, ions, and signaling molecules.