Carbohydrates, Lipids and Nucleic Acids

Carbohydrates, Lipids and Nucleic Acids

Referring to living organismsContain carbon and at least one hydrogen

“Organic”

Carbon forms 4 covalent bonds

Carbon forms branched, linear and ringed molecules.

Polymerization – combining monomers to form long chains (polymers)

Macromolecules are formed by…

CarbohydratesLipidsNucleic AcidsProteins

4 Organic Compounds (Macromolecules)

Energy sourcesForm structural compounds

Contain C, H, O (usually have 1:2:1 ratio) – (CH2O)nExample: C6H12O6

Carbohydrates

Monomers = “Monosaccharides”Ex:

Glucose (quick energy source)Fructose (in fruits)Galactose (in milk)

Carbohydrates

Glucose and Galactose

Glucose and Fructose

Molecules with the same formula but different 3D structures

Isomers

C2

CH23

C1O

OH

OH

H

H

C

CH2

CO

OH

OH

H

H C

CH2

CH2OH

OH

O

D-glyceraldehyde L-glyceraldehyde Dihydroxyacetone

Aldoses Ketose

SucroseLactoseMaltose

Disaccharides – “Two sugars”

Dehydration SynthesisWhen two molecules are bonded togetherby removing awater molecule

HydrolysisWhen two moleculesare separated by adding a watermolecule

http://academic.cengage.com/biology/discipline_content/animations/reaction_types.html

Digestion EnzymesMaltase digests maltoseLactase digests lactoseSucrase digests sucrose

Polysaccharides – “Many Sugars”

Extra sugar is stored as polysaccharides.

Polysaccharides are made from monosaccharides.

Polysaccharide that stores sugar in plants

Starch

Polysaccharide that stores extra sugar in animals\Supplies energy for muscle contractionsReleased by liver when blood sugar is low

Glycogen

Polysaccharide that composes cell wall in plants

Cellulose

Uses:Long-term energy storageInsulationWaterproof coveringFormation of membranesChemical messengers (steroids)

Lipids (fats, oils, and waxes)

Contain mostly H and CNot soluble in water (nonpolar)

Lipids

TriglyceridesSaturatedUnsaturated

PhospholipidsWaxesSteroids

Types of Lipids:

Triglyceride formationA glycerol molecule combines with three fatty

acids.

http://users.uma.maine.edu/SusanBaker/triglyceride.html

.

Saturated vs. Unsaturated

Monounsaturated

Polyunsaturated

Cis versus transCis – both of the groups of atoms are oriented on

the same side or the double bond

Trans – the groups of atoms are oriented so that one is up and the other down relative to the double bond.

Cis and trans fats (note the bends)

Cis-2-butene and trans-2-buteneExamples

Trans fat does not bendActs like saturated

Trans fats

Trans fats – source?Plants and animals do not produce trans fatsBeef and milk do have some trans fat from

bacteria that help them digestMost trans fats come from processed

vegetable fatsPartial hydrogenation or extended heating

causes cis bonds to become trans bonds

And the problem is?Trans fats (or hydrogenated fats) raise

cholesterol, Possible link with type 2 diabetesPossible link with breast and colon cancerBrain cell membranes (trans replaces cis in

myelin sheath); affects neuron communication

Steroids – special lipidsCholesterolSex hormonesBirth control pillsCortisoneAnabolic steroids

Nucleic AcidsStore and transmit hereditary informationContain H, C, N, O, P

Monomers = nucleotidesExamples:

DNARNAATP

ATP ComponentsAdenineRibose3 Phosphates