B1.1 Carbohydrates and Lipids Lecture Notes

Comprehensive flashcards covering the chemical properties of carbon, the structure and function of carbohydrates (monosaccharides, polysaccharides, cellulose, glycoproteins), and the characteristics of lipids (triglycerides, fatty acids, phospholipids, steroids).

Carbon Atom covalent capacity

Contains $4$ electrons in its outer shell, allowing it to form $4$ covalent bonds with other elements.

Macromolecule

Molecules composed of a very large number of atoms.

Condensation reaction

A chemical process that links monomers together to create polymers.

Hydrolysis reaction

A chemical reaction used to deconstruct polymers into monomers during digestion, involving the addition of water.

Pentose

A monosaccharide containing $5$ carbon molecules in a ring structure.

Hexose

A monosaccharide containing $6$ carbon molecules in a ring structure.

Glucose (Stability and Solubility)

A widely used monosaccharide that is very stable and soluble, making it easy to transport and ideal for food storage.

Glycosidic bond

The type of bond used to join monosaccharides into polysaccharides, typically forming $1-4$ or $1-6$ bonds.

Starch

A polysaccharide used for energy storage in plants, existing in two forms: amylose and amylopectin.

Glycogen

A highly branched polysaccharide used for energy storage in animals, made of tens of thousands of glucose subunits.

Amylose

An unbranched chain of $\alpha$-glucose linked by $1-4$ glycosidic bonds that forms a helical shape.

Amylopectin

A branched polysaccharide of $\alpha$-glucose linked by $1-4$ and some $1-6$ glycosidic bonds.

Cellulose

A structural polysaccharide in plants made of $\beta$-glucose linked via $\beta$ $1-4$ glycosidic bonds.

Microfibrils

Bundles of cellulose molecules that provide high tensile strength to plant cell walls.

$\beta$-glucose inversion in cellulose

The structural requirement where every alternate glucose molecule is inverted to allow the formation of $\beta$ $1-4$ glycosidic bonds.

Glycoprotein

A protein with an oligosaccharide chain attached, used for cell-cell recognition and hormone reception.

ABO Glycoproteins

Glycoproteins on red blood cells (types A, B, and O) that determine blood compatibility during transfusions.

Lipids

Non-polar organic molecules that are insoluble in water (hydrophobic) but soluble in non-polar organic solvents.

Triglyceride

A lipid formed by a condensation reaction between one glycerol molecule and three fatty acids.

Ester bond

The covalent bond formed between fatty acids and glycerol molecules in a triglyceride.

Saturated fatty acid

A fatty acid with no double bonds between carbon atoms, meaning no more hydrogen atoms can be added.

Monounsaturated fatty acid

A fatty acid containing exactly one double bond in its carbon chain.

Polyunsaturated fatty acid

A fatty acid containing more than one double bond in its carbon chain.

Cis-isomers (Fatty Acids)

Isomers where hydrogen atoms are on the same side of the double bond, causing a bend in the chain and lower melting points.

Trans-isomers (Fatty Acids)

Artificially produced isomers where hydrogen atoms are on opposite sides of the double bond, resulting in a straight chain and higher melting points.

Adipose tissue

Tissue in animals where triglycerides are stored for long-term energy storage and thermal insulation.

Phospholipid structure

A molecule consisting of a hydrophilic (polar) phosphate head and two hydrophobic (non-polar) lipid tails.

Phospholipid bilayer

A double layer of phospholipids where tails face inward and heads face outward, forming the basis of cell membranes.

Steroids

Hydrophobic lipids characterized by $4$ fused rings of carbon ($3$ cyclohexane rings) and a total of $17$ carbon atoms.