molecules- carbs and lipids

Vocabulary flashcards covering carbohydrate structures, storage polysaccharides, glycoproteins and blood typing, lipid classifications, and health implications of trans fats.

Monosaccharide

A single sugar unit; basic building block of carbohydrates (e.g., glucose).

Disaccharide

A carbohydrate formed by two monosaccharides joined via a dehydration reaction (e.g., maltose, lactose).

Polysaccharide

A large carbohydrate composed of hundreds to thousands of monosaccharides linked together (e.g., starch, glycogen, cellulose).

Monomer

An individual molecular subunit that can join with others to form polymers.

Dimer

A molecule made of two monomer units bonded together.

Polymer (Complex)

A macromolecule consisting of many repeated monomer units connected in long chains.

Dehydration Reaction

Chemical process that joins monomers by removing water, forming covalent bonds such as glycosidic linkages.

Alpha-Glucose

Cyclic glucose in which the hydroxyl group on carbon-1 lies below the ring plane; forms helical starch and glycogen.

Beta-Glucose

Cyclic glucose with the hydroxyl on carbon-1 above the ring plane; builds straight cellulose chains.

Cis Orientation (Carbohydrates)

Two hydroxyl groups on adjacent carbons positioned on the same side of the ring (both up or both down).

Trans Orientation (Carbohydrates)

Hydroxyl groups on adjacent carbons positioned on opposite sides of the ring (one up, one down).

Glucose

A polar, water-soluble monosaccharide transported in blood and used in aerobic and anaerobic respiration for energy.

Polarity

Property of a molecule having partial positive and negative charges, enabling it to dissolve other polar substances.

Osmotic Problem of Excess Glucose

High blood glucose draws water into vessels, raising pressure and risking arterial damage if not stored as glycogen.

Starch

Plant storage polysaccharide of alpha-glucose; mixture of amylose (unbranched) and amylopectin (branched).

Glycogen

Highly branched alpha-glucose polysaccharide stored in animals; minimizes solubility to prevent osmotic stress.

Amylose

Unbranched component of starch with α-1→4 linkages, forming a compact helical structure.

Amylopectin

Branched component of starch containing α-1→4 and α-1→6 linkages; branches occur at 1→6 bonds.

α-1→4 Linkage

Glycosidic bond joining carbon-1 of one alpha-glucose to carbon-4 of the next, producing linear chains.

α-1→6 Linkage

Glycosidic bond from carbon-1 to carbon-6, creating branch points in polysaccharides like amylopectin and glycogen.

Hydrolysis

Reaction that breaks covalent bonds by adding water, splitting polysaccharides into smaller sugars.

Cellulose

Structural polysaccharide of beta-glucose with alternating orientation, forming straight chains and microfibrils in plant walls.

Microfibril

Bundle of parallel cellulose molecules providing high tensile strength to plant cell walls.

Glycoprotein

Molecule composed of a carbohydrate attached to a protein, functioning in cell recognition on membranes.

Antigen (Blood Type)

Surface glycoprotein on red blood cells that determines ABO blood group identity.

Antibody

Plasma protein that binds specifically to foreign antigens, initiating an immune response.

Universal Donor (Type O)

Blood lacking A and B antigens; can be transfused to any ABO recipient without triggering antigen reaction.

Universal Recipient (Type AB)

Blood containing both A and B antigens but no anti-A or anti-B antibodies; accepts any ABO type.

Lipid

Diverse class of hydrophobic molecules, including fats, oils, waxes, and steroids; generally not polymers.

Fat

Solid lipid at room temperature with melting point ≥20 °C; often saturated triglycerides.

Oil

Liquid lipid at room temperature due to lower melting point (≈30 °C); rich in unsaturated fatty acids.

Steroid

Lipid characterized by four fused carbon rings (e.g., cholesterol, hormones).

Triglyceride

Lipid formed from glycerol bonded to three fatty acids via ester linkages, releasing three water molecules.

Ester Bond

Covalent linkage between a fatty acid and glycerol in triglycerides formed during dehydration synthesis.

Saturated Fatty Acid

Hydrocarbon chain containing no double bonds; carbon atoms fully saturated with hydrogen, making fats solid.

Unsaturated Fatty Acid

Fatty acid with one or more carbon-carbon double bonds, reducing hydrogen saturation.

Monounsaturated Fat

Unsaturated fatty acid containing exactly one double bond in its hydrocarbon chain.

Polyunsaturated Fat

Unsaturated fatty acid with two or more double bonds in the hydrocarbon chain.

Cis Fatty Acid

Unsaturated fatty acid where hydrogens at the double bond are on the same side, causing a bend and lower melting point.

Trans Fatty Acid

Unsaturated fatty acid with hydrogens on opposite sides of the double bond, producing a straight chain and higher melting point.

Partial Hydrogenation

Industrial process adding hydrogen to unsaturated oils, converting some cis bonds to trans and producing trans fats.

LDL Cholesterol

Low-density lipoprotein that transports cholesterol to tissues; elevated by trans fats, promoting arterial plaque.

HDL Cholesterol

High-density lipoprotein that transports cholesterol to the liver for removal; lowered by trans fats.

Plaque Formation (Atherosclerosis)

Accumulation of fats, cholesterol, and cellular debris in artery walls, increasing heart-attack risk, exacerbated by trans fats.