Chemistry 1010

Groceries

What Should We Eat

How Much Should We Eat

• Grasshopper Cookies

Dietary needs Come in Different Ways

• Lipids (Fats)

• Carbohydrates (sugars)

• Proteins

• Vitamins and Minerals

Lipids

• Store Energy in a Fat Cell

• Part of membranes

• Serve as chemical messengers

Where are Lipids Used

• Humans store Energy in the form of fats• Fats produce 50% more energy per gram

than Carbohydrates• Because lipids are insoluble in water, they

work well as membranes to separate compartments in the body

• The structure of lipids makes them water repellent or hydrophobic

• Primary messengers like steroids and Secondary messengers like prostaglandins or thromboxanes

Classification of Lipids

• Classified into four groups

1) Fats and waxes

2) Complex Lipids

3) Steroids

4) Prostaglandins

Structure of Fats

Properties of Fats

• Physical State - FATS– Animal fats

• generally solids at RT• contain mostly saturated FA

– Plant and Fish oils• generally liquids at RT• contain more unsaturated FA

Properties of Fats

PURE Fats – Colorless, odorless, and

tasteless– Tastes, odors, colors are

caused by substances dissolved in the fats

Hydrogenation

• Treatment with hydrogen gas, H2

• Catalyst required

• NOT difficult to convert unsaturated FA to saturated FA

• Called “hardening”

• Margarine contains more unsaturation than hydrogenated shortenings– Crisco, Spry, etc.

Hydrogenation

• Unsaturated converted to saturated:

HC

H2C

H2C C (CH2)12 CH3O

O

O

O

C (CH2)6 CH2

CH CH

CH2 (CH2)6 CH3

O

C (CH2)6 CH2

CH CH

CH2 (CH2)6 CH3

O

+ H2

catalyst

HC

H2C

H2C C (CH2)12 CH3O

O

O

O

C (CH2)6 CH2

CH2 CH2

CH2 (CH2)6 CH3

O

C (CH2)6 CH2

CH2 CH2

CH2 (CH2)6 CH3

O

Saponification

• Triglycerides are subject to hydrolysis– base hydrolysis is called “saponification”

HC

H2C

H2C C (CH2)12 CH3O

O

O

O

C (CH2)6 CH2

CH CH

CH2 (CH2)6 CH3

O

C (CH2)6 CH2

CH CH

CH2 (CH2)6 CH3

O

+ 3 NaOHH2O

H2C

HC

H2C

OH

OH

OHC (CH2)12 CH3O

O

Na+ -

+

O C (CH2)6 CH2

CH CH

CH2 (CH2)6 CH3

O

Na+ -2

Carbohydrate

• hydrate of carbon – Cn(H2O)m

• Glucose -blood sugar- C6H12O6 or C6(H2O)6

• Sucrose -table sugar- C12H22O11 or C12(H2O)11

• Not all carbohydrates have this exact form

– old habits die slow or sometimes never at all

Monosaccharides

• Formula CnH2nOn • One carbon is either an aldehyde or

ketone• The suffix ose indicates that the

molecule is a carbohydrate• Use prefix to indicate number of

carbons tri , tetr, pent, hex• Aldose – contain an aldehyde group• Ketose – contain a ketone group

Monosaccharides

• Aldohexoses

Aldohexosesaldehyde function

six carbons

carbohydratesor

saccharides

other examples: ketotetrose, aldotriose, ketopentose

Three Most Common Sugars

Three Forms of A Sugar

Disaccharide Examples

Polysaccharide Examples

O

O

O

HOCH2

OH

OH

OH

OH

HOCH2

)(O O

OHOCH2

OH

OH

OH

OH

HOCH2

)

(Starch

alpha linkage Cellulose beta linkage

What A Difference One Bond Angle Can Make

Sawdust Cookies anyone??????

Proteins

Functions:– Structure - skin, bones, hair, fingernails– Catalysis - biological catalysts are enzymes– Movement - muscle: actin and myosin– Transport - hemoglobin, transport thru

membranes– Hormones - insulin, oxytocin, HGH, etc.– Protection - antigen-antibody reactions,

fibrinogen in clotting– Storage - casein in milk, ovalbumin in eggs,

ferritin in liver-stores iron– Regulation - control in expression of genes

From yahoo images

Proteins• Protein types:

– 9000 different proteins in a cell– Individual human being >100,000 different – Fibrous Protein

• Insoluble in H2O• Used mainly for structural purposes

– Globular Protein• Partly soluble in H2O• Usually not used for structural purposes

From yahoo images

Amino Acids• The Building Blocks of proteins

– Contains an amino group and an acid group– Nature synthesizes about 20 common AA

COOHC

NH2

R

H

Amino Acids• Amino Acids (AA)

– The twenty common are Called alpha amino acids

– We use one and three letter codes to name the 20 common AA

COOHC

NH2

R

H

Amino Acids• Amino Acids (AA)

– Sometimes classifiedas AA with:

• nonpolar R groups• polar but neutral R groups• acidic R groups• basic R groups

Twenty Essential Amino Acids

http://chemed.chem.purdue.edu/genchem/topicreview/bp/1biochem/amino2.html

Peptides• AA are also called peptides

• They can be combined to form a dipeptide.

a peptide bond

CCHH2N

OH

CCH

CH3

NH OH

O

glycine

CCHH2N OH

OH

+

alanine

CCH

CH3

H2N OH

O-H2O

Peptides• Addition of peptides (head to tail)

– Formation of:• dipeptides• tripeptides• tetrapeptides• pentapeptides• polypeptides• PROTEINS

AA’s

Proteins• Proteins usually contain about 30+ AA• AA known as residues

– One letter abbreviations• G, A, V, L

– Three letter abbreviations• Gly, Ala, Val, Leu

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Polypeptides• Polypeptides

CCHN

R

OH

CCHN

R

OH

CCHN

R

OH

CCHN

R

OH

CCHN

R

OH

CCHN

R

OH

peptide bonds peptide bonds

side chains

amino acidresidues

AA’s

How a Protein is Formed

http://www.youtube.com/watch?v=D5vH4Q_tAkY