Cell Junctions Review

What structures make up muscle cells?

Myofibrils

What filaments make up myofibrils?

Actin and Myosin

How does moving an arm or leg occur via muscle cells?

They contract and expand together

How do bone cells form bones?

They secrete calcium and other materials that harden

What are cell junctions?

Structures that connect cells to each other

In what tissue are cell junctions most commonly found?

Epithelial

What kind of junction is depicted?

Tight Junction

What kind of junction is depicted?

Desmosome

What kind of junction is depicted?

Gap Junction

What sorts of molecules can pass through a tight junction?

Nothing

Where can we find tight junctions?

Bladder, Intestines, and Kidney’s

Where do desmosomes attach at?

The cytoskeleton

What sorts of molecules can pass through a desmosome?

Water and Ions

Where can we find desmosomes?

Skin and Intestines

What do gap junctions allow to occur?

The passing of water and ions between cells 

Where can we find gap junctions?

Cardiac Muscles and Neurons

What are the four tissue types found in animals?

Epithelial, Connective, Muscle, and Nerve

What is the function of epithelial tissue?

Covers and lines body surface, provides protection

What is the function of connective tissue?

Provides structural support and connects other tissues

What is the function of muscle tissue?

Contracts to enable movement

What is the function of nervous tissue?

Transmits electrical impulses

Which of the following organelles often occupies the majority of the volume of a plant cell?

Central Vacuole

Specialized epithelial cells that protect underlying tissues and organs

Keratinocytes

Specialized epithelial cells that produce the pigments of skin

Melanocytes

What does extracellular meaning?

Outside the cell

What are the three types of fibers within the cytoskeleton?

Microtubules, Microfilaments, and Intermediate filaments

What is dynamic instability?

The cycles of polymerization and depolymerization in microtubules

Why does microtubule catastrophe take place?

The plus end of a microtubule is structurally unstable

What is the process of microtubule catastrophe?

The dramatic shrinkage of microtubule

What is epidermolysis bullosa?

A genetic defect that disrupts the intermediate filament network

What cell-surface proteins attach cells to each other and to the extracellular matrix?

Integrins

Where are microtubules found?

The interior of the cell

What do microtubules do?

They maintain cell shape and provide transport

Where are microfilaments found?

Around the inner edge of a cell

What do microfilaments do?

Resist tension, provides cell shape and movement

Where are intermediate filaments found?

Throughout the cell

What do intermediate filaments do?

Holds organelles in place, provides structural support to the cell

A double helix of actin monomers is…

A microfilament

A strong fiber composed of intermediate filament protein subunits is…

An intermediate filament

A hollow tube formed from tubulin dimers is…

A microtubule

What are motor proteins used for?

Moving cells, changing cell shape, and moving substances inside and outside of cells

In which direction does Kinesin move granules out towards?

The plus end

When does kinesin move the granules?

During dispersal

In which direction does Dynein move granules out towards?

The minus end

When does dynein move the granules?

During Aggregation

What subunits make up microtubules?

Tubulin dimers

What subunits make up microfilaments?

Actin monomers

Which cell junction type is depicted?

Hemidesmosome

Which cell junction type is depicted?

Adherends

What is another name for microfilaments?

Actin

What are myofibrils?

Rod-like organelles found in muscle cells that are responsible for muscle contraction

What is the function of hemidesmosome junctions?

They anchor epithelial cels to the basal lamina