Cell-Cell Contacts and Microscopy

These flashcards cover the key concepts of microscopy techniques, cell-cell contacts, and the extracellular matrix as discussed in the lecture.

What is resolving power in microscopy?

Resolving power is the ability to distinguish two separate points.

What happens when a microscope has lower resolution?

It shows two close-together points as a blur.

What microscopy technique provides a high level of detail for small structures?

Transmission Electron Microscopy (TEM).

What are the main types of microscopy techniques mentioned?

Light microscopy, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Fluorescence microscopy.

How do light microscopes visualize specimens?

They shine light on an object and use lenses to magnify the image.

What distinguishes electron microscopes from light microscopes in terms of visualization?

Electron microscopes use electrons to visualize the object and provide much higher resolution.

What is the extracellular matrix (ECM) in animal cells?

A fiber composite secreted by most animal cells that provides structural support.

What are the primary components of the extracellular matrix?

Gelatinous polysaccharide ground substance and a network of protein fibers, primarily collagen.

What is the function of the collagen fibers in the extracellular matrix?

They provide structural support and are more elastic than cellulose.

What are integrins in relation to the cytoskeleton?

Transmembrane proteins that link the cytoskeleton to the extracellular matrix.

What role do tight junctions play between animal cells?

Tight junctions form a watertight seal between adjacent cells, preventing leakage.

What are desmosomes?

Adhesive junctions that link the cytoskeletons of adjacent cells.

What is the function of cadherins?

They are cell adhesion proteins found in desmosomes that aid in selective adhesion between cells.

What type of cell communication occurs through gap junctions?

Direct connections that allow small molecules to flow between adjacent cells.

What do plasmodesmata connect in plant cells?

They connect the plasma membranes, cytoplasm, and smooth ER of two adjacent cells.

What allows multicellular organisms to maintain function through structural connections?

Cell-cell contacts such as tight junctions and desmosomes.

What is a key difference between the extracellular material in plants and animals?

Plants use plasmodesmata for communication, while animals use gap junctions.

What two structures facilitate communication between adjacent cells?

Plasmodesmata in plants and gap junctions in animals.

What is the purpose of cell communication via cell-cell gaps?

To allow cells to communicate and work together in a coordinated fashion.