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Macromolecules carbohydrates, lipids, proteins, nucleic acids

•  Monomers and Polymers –  dehydration reactions

•  Carbohydrates –  Sugars and starches

•  Lipids –  Fats and oils –  Phospholipids –  How soap works

•  Start proteins, if time 14 Sept. 2020

Figure 5.2 (a) Dehydration reaction: synthesizing a polymer

1 2 3

Dehydration removes a water molecule, forming a new bond.

1 2 3 4

H2O

(b) Hydrolysis: breaking down a polymer

1 2 3 4

H2O Hydrolysis adds a water molecule, breaking a bond.

1 2 3 H

Sugars Aldoses

(Aldehyde Sugars) Ketoses

(Ketone Sugars) Trioses: three-carbon sugars (C3H6O3)

Glyceraldehyde Dihydroxyacetone

Pentoses: five-carbon sugars (C5H10O5)

Ribose Ribulose

Hexoses: six-carbon sugars (C6H12O6)

Glucose Galactose Fructose

(Understand, but don�t memorize structures)

Monosaccharides

Glucose

Ribose

Glucose

CH2OH H

2 1 2 1

Fructose

CH2OH

CH2OH

CH2OH CH2OH

CH2OH

Sucrose

OH

H

HO

H O O O

O

O

H2O

Simple sugars can be linked by Dehydration reactions

Sucrose is a common disaccharide:

Glucose+Fructose

Other common disaccharides

Do not memorize

2

Fig. 5-8 β  Glucose monomer

Cellulose molecules

0.5 µm

10 µm

Cellulose Small difference in structure, big difference in function.

Starch:

Cellulose:

Lipids (fats and oils)

http://www.johnnyjet.com/images/PicForNewsletterItalyMarch2005FRIEDDOUGHnLARD.JPG

Fried dough with lard . . . .

Fats or triglycerides (glycerol + 3 fatty acids)

Fat molecule

H H H H

H H H

H H

H H

H H

H H

H O

H O H C

C

C

H

H OH

OH

H

H H

H H

H H

H H

H H

H H

H H

H

H C C C

C C

C C

C C

C C

C C

C C C

Glycerol + Fatty acid

H

H

H

H

H H

H H

H H

H H

H H

H H

H H

H H

H H H H

H H H H H H H H H H H H

H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H

H H H H H H H H H

H H

H H H H H

H H

H H H H H H

H H H H H

H H

HO

O

O

O

O C

C

C C C C C C C C C C C C C C C C C

C

C C C C C C C

C C C C C C C C C

C C C C C C C C

C C C C

C C

C

O

O

Dehydration reaction

Figure 5.11 hydrophilic or hydrophobic?

FATS OILS Solid Liquid

WHY?

Saturated Unsaturated or

Polyunsaturated Like Fig 5-12

What are trans fats?

3

Polar (charged) Head

Very Hydrophobic Tail In water

they can form a “micelle” -- why?

“Amphipathic”

Fatty Acids Why soap works

•  Grease is attracted to the interior of the micele

Soap micele

Hydrophilic heads

Hydrophobic tails

Greasy mess on plate

•  Phospholipids –  Glycerol + 2 fatty acids + phosphate

CH2

O P O O O

CH2 CH CH2 O O

C O C O

Phosphate

Glycerol

(a) Structural formula

Fatty acids

Hyd

roph

obic

tails

–

Hyd

roph

ilic

head

CH2 Choline +

Figure 5.13

N(CH3)3

Hydrophilic �head� Hydrophobic �tails�

How will phospholipids behave in water?

Form Boundaries

Phospholipid Bilayer

Proteins

What are some of the functions of proteins?

Can Keep adding to the end

R5 Oil OH Duracell

SH

Nonpolar Polar Charged

Polymers of Amino Acids •  Amino Acids differ only by their �R� group •  20 kinds of amino acids

–  Same chasis, different cargo

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Nonpolar Side Chains

Glycine (Gly or G)

Alanine (Ala or A)

Valine (Val or V)

Leucine (Leu or L)

Isoleucine (Ile or I)

Methionine (Met or M)

Phenylalanine (Phe or F)

Tryptophan (Trp or W)

Proline (Pro or P)

Polar Side Chains

Serine (Ser or S)

Threonine (Thr or T)

Cysteine (Cys or C)

Tyrosine (Tyr or Y)

Asparagine (Asn or N)

Glutamine (Gln or Q)

Charged Side Chains

Basic (positively charged)

Acidic (negatively charged)

Aspartic acid (Asp or D)

Glutamic acid (Glu or E)

Lysine (Lys or K)

Arginine (Arg or R)

Histidine (His or H)

The amino and acid groups couple the monomers together

•  Can make polymers that are 100s or 1000s of amino acids long

Can Keep adding to the end

R1 R2 R3 R4 R5

4 Levels of Structure

Secondary Structure: Local folding α helix and β sheet

Primary Structure: Amino acid sequence

Tertiary Structure: 3-D shape of one polypeptide Quaternary Structure:

Assembly of several polypeptides to form one functional protein