Cell Biology Weekly Quiz 3

Nucleic Acid Structure

• The backbone of nucleic acids is stabilized by phosphodiester bonds.

Condensation Reactions

• Products of condensation reactions typically include water and larger biomolecules such as carbohydrates or proteins.

Functions of Membranes

• Membranes serve as barriers, controlling substance movement in and out of cells and organelles and facilitating communication between cells.

Extracellular Matrix Components

• Components of the extracellular matrix in animal cells can include collagen, glycoproteins, proteoglycans, and fibronectin.

Plant Cell Structure

• Plant cells possess a rigid cell wall that supports structure and has channels known as plasmodesmata for cytoplasmic exchange between neighboring cells.

Animal Cell Structure

• Animal cells lack a traditional cell wall but can form junctions like adherens junctions and desmosomes to maintain connections between cells.

Junctions in Cell Adhesion

• Adherens junctions and desmosomes utilize cadherins for cell adhesion and are anchored to the cytoskeleton, facilitating structural integrity.

Epithelial Cell Characteristics

• The impermeability of the epithelium lining the bladder is primarily due to tight junctions that prevent leakage of substances.

Intestinal Epithelial Cells

• Certain cell junction types, such as gap junctions, may not be present in intestinal epithelial cells, which typically contain tight junctions and desmosomes.

Lipid Bilayer Permeability

• Small non-polar molecules, such as oxygen or carbon dioxide, can diffuse directly through the lipid bilayer most easily due to their size and hydrophobic nature.

Glycoprotein Differences

• N-linked glycoproteins have their carbohydrate groups attached to nitrogen in the amino acid asparagine, while O-linked glycoproteins attach to serine or threonine via oxygen.

Cell Adhesion Roles

• Molecules such as integrins and selectins play roles in cell-cell or cell-extracellular matrix adhesion, while others, like certain lectins, may not facilitate adhesion functions.

Test your knowledge on the bonds that stabilize the backbone of nucleic acids with this quiz. Identify the key interactions that play a crucial role in maintaining the structural integrity of DNA and RNA.