biological molecules flashcards

properties of water with examples

• metabolite for metabolic reactions ex. condensation + hydrolysis reactions, photosynthesis

• solvent where metabolic reactions occur ex. cytoplasm

• high heat capacity ex. large amount energy needed to raise temp of large body of water small amount

• large latent heat of vaporisation ex. losing small amounts of water through evaporation has cooling effect

• strong cohesion between water molecules ex. produces surface tension where water meets air

• ice less dense than water

carbohydrates: monosaccharides

• simplest form carbohydrate

• soluble, sweet, found in many foods

• formula: (CH₂O)_n

• hexose and pentose sugars

monosaccharides: hexose sugars

6 carbon atoms per molecule

• glucose

• fructose

• galactose

monosaccharides: pentose sugars

5 carbon atoms per molecule

• ribose

• deoxyribose

monosaccharides: alpha + beta-glucose

2 isomers of glucose

• alpha-glucose - hydroxyl group below

• beta-glucose - hydroxyl group above

what properties of glucose allow it to be a primary energy source

• soluble: hydroxyl groups form hydrogen bonds w water so transported around organisms

• bonds store lots energy: energy released when bonds broken

disaccharides

2 monosaccharides joined tgt

• maltose: glucose+glucose

• sucrose: glucose+fructose

• lactose: glucose+galactose

disaccharide formation + breakdown

• created via condensation reaction

• broken by hydrolysis reaction

reactions involve formation/breakdown of covalent bond (glycosidic bond)

condensation reaction

2 monosaccharides join

hydroxyl group on carbon 1 of one monosac reacts w hydroxyl group on carbon 4 of another monosac

1-4 glycosidic bond formed + water released

hydrolysis reaction

when water added to disaccharide, glycosidic bond broken to release 2 monosacs