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Chapter 2:

The Molecules of the Cell

subunits and macromolecules sugars and polysaccharides fatty acids and lipids amino acids and proteins nucleotides and nucleic acids

interactions between macromolecules

References 4thed: p. 50-64

(3rded: p. 50-63

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!he four ma"or families of

organic molecules in the cell

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#ormation of macromolecules

by condensation reactions

$ubunits are added to one end of a growing chain by

dehydration synthesis.

%e&erse reaction:_________

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#ormation of disaccharides

!he condensation of

two monosaccharides

produces one disaccharide.

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#atty acids

' structural formula of

a________ fatty acid

ball-and-stic) model

* space-filling model

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#atty acids are stored as energy reser&es (fats and oils

through an ester linkageto glycerol to form triacylglycerols.

!riacylglycerols

glycerol fatty acids

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#ats

(!riacylglycerols

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$aturated fatty acids tend toformaggregatesand deposits

within the walls of blood &essels causing atherosclerosisof coronary blood &essels (coronary heart disease

+nsaturated fatty acids:

cisunsaturated fatty acids do notform solid aggregates

transunsaturated fatty acids beha&e similar to saturated

fatty acids , they tend to aggregate and form solid

deposits

#atty acids

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#atty acids

'l)enehydrogenation

'l)aneincomplete

'l)enestereoisomer

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leic acid is a cisunsaturated fatty acid that comprises

up to 0/ of oli&e oil.

laidic acid is a transunsaturated fatty acid and a ma"or

trans fat found in partially hydrogenated &egetable oils.

oth fatty acids are isomers of the same molecule.

#atty acids

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1hospholipids

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1hospholipids in biological membranes

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1hospholipids

Phospholipids in biological membranes typically contain

one saturated and one unsaturated fatty acid:

saturated fatty acids ma)e the membrane less fluid

because they tend to aggregate

cisunsaturated fatty acids reduce membrane rigidity

because they do not form solid aggregates

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'mino acids

22222222 one of the simplest amino acids.

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'mino acids

-3 -*-

% group(-*3

-carbon

7oni8ed alanine

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' polypeptide

Peptide bonds

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'denosine triphosphate: a nucleotide

'!1

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omenclature of nucleosides and nucleotides

Ribonucleosides

9uanosine

'denosine

*ytidine

+ridine

Deoxyribonucleosides

eo;yguanosine

eo;yadenosineeo;ycytidine

eo;ythymidine

%ibonucleosides or

eo;yribonucleosides

phosphates

,Nucleotides

add:

monophosphatediphosphate

triphosphate

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' nucleic acid

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!he use of '!1 as an energy carrier in the cell

li l id

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' cyclic nucleotide

*yclic adenosine monophosphate

(c'

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!he relati&e abundance of

macromolecules in cells

1 l h i f i b i

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1olymers: chains of monomeric subunits

1olysaccharides polypeptides and polynucleotides form

from the covalentbonding of their monomeric subunits.

!h i i b l l

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!he interaction between macromolecules

7nteractions between macromolecules are mediated by

noncovalentbonds of compatible groups.

!h i t ti b t l l

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!he interaction between macromolecules

Noncovalentinteractions between a protein and its

bound ligand in this e;ample cyclic '

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!he interactions of macromolecules in cells

result in macromolecular comple;es

!he assembly of a ribosome.