W10 L2 - Polysaccharides

Flashcards covering polysaccharides, their structures, functions, and roles in cell communication and infection.

What is a key concept to remember when studying monosaccharides, disaccharides, and polysaccharides?

A key concept to remember is the encoding and storage of biological information through these saccharides. Whether in energy storage, such as starch and glycogen, or structural components like cellulose, these carbohydrates play essential roles in biological systems.

What is the extracellular matrix?

A carbohydrate protein matrix that sits around cells and encodes information important to life, such as how tissues organize.

Are monosaccharides linear, cyclic, or both?

Both.

How are anomers interconverted?

Through mutarotation.

In the name alpha D fructofuranose, what does furanose indicate?

The structure is cyclic.

Specifically, it refers to a five-membered ring structure formed by the condensation of the sugar with itself.

In the name alpha D fructofuranose, how many points are there in the ring?

Five.

In the name alpha D fructofuranose, what does D indicate?

The last carbon (carbon 5) is above the ring.

In the name alpha D fructofuranose, what does alpha indicate?

The hydroxyl on carbon one is on the opposite side of the ring to carbon five.

Is Maltose reducing or non-reducing?

Reducing because it has a hemiacetal group.

Is Lactose reducing or non-reducing?

Reducing because it has an anomeric carbon

Is Sucrose reducing or non-reducing?

Non-reducing because the two anomeric carbons have formed a glycosidic linkage.

Is Trehalose reducing or non-reducing?

Non-reducing because the anomeric carbons are bonded to oxygen.

What are polysaccharides also known as?

Glycans.

What is a homo polysaccharide?

A long chain of monosaccharides formed from one monosaccharide.

What is a hetero polysaccharide?

A long chain of monosaccharides formed from multiple different sugars.

What are the storage polysaccharides discussed in the lecture?

Starch and glycogen.

What is the structural polysaccharide discussed in the lecture?

Cellulose.

What are phi and psi angles?

Angles that arise from the rotation of single bonds in the glycosidic bond, which imbue a three-dimensional structure on polysaccharides.

What is amylose?

A storage polysaccharide found in plants and is one component of starch; it is a long, unbranched chain of glucose molecules forming a helix.

What is amylopectin?

A component of starch that can form branches, creating a double helix structure.

What is glycogen?

A storage compound in animals, similar to amylopectin but with more frequent branches, leading to tighter packing.

Why are storage polysaccharides insoluble and formed into granules?

To avoid contributing to the osmolarity of the cell, which could cause water to rush in and rupture the cell membrane.

What is cellulose?

A structural polysaccharide found in plant cells that is linear, unbranched beta-glucose that forms straight structures and sheets that interact with each other through hydrogen bonding.

What is the difference between cellulose and starch?

Starch is the alpha anomer and forms a helix, while cellulose is the beta anomer and forms a flat, planar structure.

What is Chitin?

The second most abundant polysaccharide in nature. It is found in the exoskeletons of insects and arthropods, and it polymerizes to form hard structures.

How does phosphorylation of glucose trap it inside a cell?

Adding a phosphate group to carbon 6 of glucose tracks and forces it through glycolysis and energy metabolism pathways.

What is peptidoglycan?

A polysaccharide that contains peptides involved in the bacterial cell wall.

What cell structure contains peptidoglycan?

Bacterial cell wall.

Name two complex carbohydrates.

Proteoglycans and glycoproteins.

What is the glycocalyx?

A shell of polysaccharide around a cell that functions in signaling and communication.

How do glycosylated proteins help cells communicate?

Glycoproteins on cells interact with lectins on other cells, allowing them to recognize and decode the cell type.

How do viruses and bacteria exploit glycoproteins for infection?

Viruses and bacteria target specific glycoproteins on cells to gain entry and colonize.

How does penicillin work as an antibiotic?

It inhibits peptidoglycan synthesis, preventing the formation of bridges in the bacterial cell wall, ultimately causing the cells to swell and die.