SEM 1 - MACROMOLECULES 1: CARBOHYDRATES

Carbohydrates

Macronutrient found in food and drinks, which can be broken down into energy. Either a polyhydroxy ketone or aldehyde.

Monosaccharide

Simple Sugar unit like glucose or fructose

Polysaccharide

Consists of 100-1000 monosaccharide units

Oligosaccharides:

Has three or more monosaccharides, often associated with lipids or proteins as glycoconjugates

Homopolysaccharides and its general role

Has the same type of monosaccharide units. Useful as energy storage or structural support.

Heteropolysaccharides and Function

Different type of monosaccharide units. Useful for tissue structure, hydration, and lubrication.

Glycosidic Linkage

Monosaccharides linked through glycosidic bond, which involves the loss of water. Numbering based on carbons.

Alpha Glycosidic Bond:

Hydrogen at the top

Beta Glycosidic Bond:

Hydrogen at the bottom

Hyaluronic Acid

A polysaccharide made up of repeating glycosaminoglycans that gives cartilage and skin toughness and flexibility.

Polysaccharide Insolubility and Advantages for Bacteria + Mammals

Polysaccharides like glycogen are relatively insoluble due to their size and branching structure. The branching leads to a compact form, reducing osmotic pressure and preventing cell lysis.

Branching

Divide into one or more subdivisions.

Glycogen Structure and Branching for Fight/Flight Response

A homopolysaccharide made up of glucose units linked by alpha-1,4 glycosidic bonds, with branches formed by alpha-1,6 linkages every 8-12 residues. Highly branched structure allows for rapid glucose release, aiding in energy availability during fight-or-flight response.

Tissues storing glycogen in the body

Primarily stored in the liver (about 7% of wet weight) and muscles.

Peptidoglycan

A structural polysaccharide forming bacterial cell walls, composed of glycosaminoglycans linked by peptide bonds, providing rigidity and preventing cell lysis.

Lysozyme

Hydrolyses the glycosidic bonds in peptidoglycan, leading to bacterial cell death (found in tears).

Proteoglycans Structure

Has a core protein linked to glycosaminoglycans. Forms a major component of the extracellular matrix, providing structural support and facilitating nutrient movement in tissues.

Glycoproteins

Proteins with attached oligosaccharides involved in cell signaling, transport, and immune markers.

Proteoglycans

Carbohydrate-rich molecules primarily composed of glycosaminoglycans, contributing to tissue structure and hydration.

Lipopolysaccharides

Complex molecules found in some bacterial membranes that cause immune responses and can trigger severe reactions in hosts.