Transcript Chemistry 1010

Chemistry 1010
Groceries
What Should We Eat
How Much Should We Eat
• Grasshopper Cookies
Dietary needs Come in Different Ways
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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:
O
H2 C O C (CH2 )12 CH3
O
HC O
H2C O
CH 2 (CH2 )6 CH 3
C (CH2 )6 CH 2
O
CH CH
CH 2 (CH2 )6 CH 3
C (CH2 )6 CH 2
CH CH
+ H2
catalyst
O
H2 C O C (CH2 )12 CH 3
O
HC O
H2C O
CH 2 (CH2 )6 CH 3
C (CH2 )6 CH 2
O
CH 2 CH 2
CH 2 (CH2 )6 CH 3
C (CH2 )6 CH 2
CH 2 CH 2
Saponification
• Triglycerides are subject to hydrolysis
– base hydrolysis is called “saponification”
O
H2 C O C (CH2 )12 CH3
O
HC O
H2C O
CH 2 (CH2 )6 CH 3
C (CH2 )6 CH 2
O
CH CH
CH 2 (CH2 )6 CH 3
C (CH2 )6 CH 2
H2O
+ 3 NaOH
O
CH CH
H2C
HC
Na + O C (CH2 )12 CH 3
OH
OH +
H2 C OH
O
2
Na + O C (CH2 )6 CH 2
CH
CH 2 (CH2 )6 CH 3
CH
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
Aldohexoses
aldehyde function
six carbons
carbohydrates
or
saccharides
other examples: ketotetrose, aldotriose, ketopentose
Three Most Common Sugars
Three Forms of A Sugar
Disaccharide Examples
Polysaccharide Examples
What A Difference One Bond Angle Can Make
HOCH2
HOCH2
HOCH2
(
O
OH
Starch
O
OH
O
OH
O
OH
HOCH2
)
OH
alpha linkage
(
O
OH
Cellulose OH
Sawdust Cookies anyone??????
O
)
OH
beta linkage
Proteins
Functions:
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From yahoo images
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
Proteins
• Protein types:
From yahoo images
– 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
Amino Acids
• The Building Blocks of proteins
– Contains an amino group and an acid group
– Nature synthesizes about 20 common AA
H
R
C
COOH
NH 2
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
H
R
C
COOH
NH 2
Amino Acids
• Amino Acids (AA)
– Sometimes classified
as AA with:
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nonpolar R groups
polar but neutral R groups
acidic R groups
basic R groups
Twenty Essential Amino Acids
http://chemed.chem.purdue.edu/genchem/to
picreview/bp/1biochem/amino2.html
Peptides
• AA are also called peptides
• They can be combined to form a dipeptide.
H
H2N
O
CH 3 O
CH C OH + H2 N CH C OH
glycine
alanine
H
H2 N
-H2 O
O
CH C
CH 3 O
NH CH C OH
a peptide bond
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
Polypeptides
side chains
• Polypeptides
R
R
R
R
R
R
N
CH C
N
CH C
N
CH C
N
CH C
N
CH C
N
CH C
H
O
H
O
H
O
H
O
H
O
H
O
amino acid
residues
peptide bonds
peptide bonds
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.
AA’s
How a Protein is Formed
http://www.youtube.com/watch?v=D5vH4Q_t
AkY