Download Organic Chemistry

Organic Chemistry
•Organic – molecules that have a carbon
skeleton and also contain some hydrogen
atoms
•Carbon is versatile because can form many
bonds allowing for vast array of organic
molecules
•Functional groups – groups of atoms
attached to the carbon backbone that
determine the characteristics and chemical
reactivity of the molecule
•Organic molecules are synthesized by
linking small organic molecule
subunits (monomers) together to form
a long chain called a polymer
•Monomers are linked together by a
condensation reaction (dehydration
synthesis)
•Monomers are broken apart by
hydrolysis – a water molecule is added
to the reaction and broken apart to
separate monomers
Carbohydrates
•Composed of carbon,
hydrogen, and oxygen (CH2O)n
•Important source of energy
•Important structural support for
single cells, plants, fungi,
bacteria, and insects
Simple Sugars monosaccharides
•Composed of 3 to 7
carbon atoms – “circle up”
into a ring when dissolved
in water
•Glucose (C6H12O6) most
common monosaccharide
in living organisms
•Body’s main source of
energy
•Other monosaccharides
include fructose,
galactose, ribose, and
deoxyribose
Disaccharides and
Polysaccharides
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Disaccharides – two single sugars linked together
(examples: maltose, sucrose, lactose)
Polysaccharides – long chains of single sugars
1. Starch – long term energy (glucose) storage for plants
2. Glycogen – energy storage (glucose) for animals
3. Cellulose – structural support for plants (makes up cell
walls)
a. Highly insoluble
b. Bonds btw glucose units are β linkages instead
of α linkages
c. Animals cannot digest cellulose
Lipids
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Contain carbon, hydrogen, and oxygen
and may contain phosphorus and
nitrogen – highly insoluble (hydrophobic)
Functions:
1.
2.
3.
4.
5.
Energy storage molecules
Provide insulation
Forms waterproof covering
Make up the bulk of cell membranes
Act as hormones
Three types of lipids
1. Oils, fats and waxes
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Contain only carbon, hydrogen, and oxygen
Contain glycerol bonded to 3 fatty acid
subunits
2. Phospholipids
•
Similar to oil except one fatty acid is
replaced with a polar phosphate group –
primary component of cell membranes
3. Steroids
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Structurally different from other lipids
Composed of 4 rings of carbon fused
together with various functional groups
Proteins
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•
Molecules composed of one or more chains of
amino acids
Functions of proteins:
1.
2.
3.
4.
Structure (skin, hair, nails, horns)
Movement (muscles)
Defense (antibodies)
Storage of energy and materials (albumin in egg
whites)
5. Transport (hemoglobin to carry O2)
6. Signals/hormones (neurotransmitters, protein
hormones)
Amino Acids
•Building blocks of proteins
•20 different kinds – all have the same
fundamental structure, differ based on R group
•R group gives each amino acid it’s distinctive
properties (size, water solubility, electrical charge)
•Cysteine has sulfur in it’s R group causing it to
form bonds with other cysteines forming disulfide
bridges
•Amino acids are linked together by
condensation reactions linking the amino
group (-NH2) of one amino acid to the
carboxyl group (-COOH) of the next
forming a peptide bond
•Polypeptides vary in length between 3
amino acids to thousands of amino acids
Proteins have four levels of
structure
•Primary structure – specific
sequence of amino acids
coded for by the DNA
(different proteins have
different sequences
•Secondary structure –
hydrogen bonds cause
protein chains to coil or
fold (α helix or β pleated
sheet are common
structures)
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•
Tertiary structure – secondary structure folds into a
complex, 3-D specific shape
Caused by:
1. Disulfide bridges between cysteines
2. Cellular environment – whether protein is
dissolved in water of cytoplasm or in lipids of
membrane (hydrophobic/hydrophilic interactions
of amino acids)
3. Polar amino acids
will orient
themselves to watery
environments
4. Non-polar amino
acids will orient
themselves away
from water
•Quaternary
structure – proteins
that consist of 2 or
more independent
polypeptide chains
held together by
hydrogen bonds (ex.
Hemoglobin)
The shape of a protein allows it to
perform it’s function
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Exact type, position and number of amino acids with
specific R groups determines both the structure (shape)
of the protein and it’s biological function
If the shape is changed, the protein will NO LONGER
function the same way
Denatured proteins – have lost most of their secondary,
tertiary, and quaternary structure (THE SHAPE HAS
CHANGED – protein will no longer function the same
way)
1. Causes:
a. Extremes in temperature (over 60oC)
b. Extremes in pH
c. Excessive radiation
d. Electricity
e. Certain chemicals
Conjugated proteins
•Proteins that have a nonproteinaceous
prosthetic group attached – ex. Hemoglobin
contains iron which alters the properties of the
protein (increases affinity for O2)
Fibrous vs Globular Proteins
• Fibrous proteins – tertiary structure
that is a long, much-coiled chain,
often insoluble
– Ex. Collagen (skin, bone and tendons)
and keratin (hair, horns, nails)
• Globular proteins – tertiary structure
is more spherical, usually highly
soluble in water
– Ex. enzymes, hormones, insulin
Nucleic Acids
•
•
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Long chains of similar but not identical
subunits called nucleotides
Make up the hereditary information (genes)
Nucleotides have a three-part structure:
1. A five-carbon sugar (ribose or deoxyribose)
2. A phosphate group
3. A nitrogen-containing base
There are two types of nucleotides
•Ribose nucleotides (contain the
sugar, ribose)
 bond to four types of nitrogen
bases: adenine, guanine,
cytosine, and uracil
•Deoxyribose nucleotides (contain the
sugar, deoxyribose)
 bond to adenine, guanine,
cytosine, and thymine
Nitrogen bases are divided into
two groups
1. Purines – double ring structure (adenine and
guanine)
2. Pyrimidines – single ring structure (thymine,
cytosine, and uracil)
•Nucleotides are strung
together in long chains to
form nucleic acids
•Phosphate group of one
nucleotide covalently bonds
to the sugar of the next
•
Two types of Nucleic
Acids
Deoxyribonucleic Acid (DNA)
1. Double helix
2. Deoxyribose sugar
3. Contains A, C, T, and G (A-T, C-G)
4. Makes up chromosomes of all living things
5. Sequence of nucleotides spells out
information to construct proteins
• Ribonucleic Acid (RNA)
1. Single helix
2. Ribose sugar
3. Contains A, C, U, and G (A-U, C-G)
4. RNAs are copies of DNA – carries
message to cell to direct synthesis of
proteins
Nucleotides have many functions – not
all are part of nucleic acids
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May exist singly or occur as parts of other
molecules
Some act as intracellular messengers to carry
information from cell membrane to other molecules
in cell – ex. cyclic AMP
Some nucleotides have extra phosphates groups –
ex. Adenosine triphosphate (ATP), Adenosine
diphosphate (ADP)
1. Unstable molecules that carry energy from place
to place – pick up energy where it is produced
(cellular respiration) and give up energy to drive
energy demanding reactions elsewhere
•Certain nucleotides assist enzyme in their role of
promoting chemical rxns – coenzymes – usually consist
of a nucleotide combined with a vitamin