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Organic Compounds
Important Organic Compounds
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Carbohydrates
Lipids
Proteins
Nucleic Acid
ATP (Adenosine TriPhosphate)
Carbohydrates (only 2 -3% of body mass)
– Contain carbon, hydrogen, and oxygen
(hydrated carbon)
– Include sugars,starches, glycogens, and
cellulose
– Classified according to size
• Monosaccharides
• Disaccharides
• Polysaccharides
Monosaccharides- “one sugar” monosaccharides are
simple sugars occurring in single chain or single
ring structures with 3-7 carbon atoms. Glucose
(blood sugar) is the universal cellular fuel.
Diabetics should take glucose reading at least 4 times a day, before meals and at bedtime.
Aim for a range between 80 - 120 before meals and 100 - 140 at bedtime. It will go up and
down over the course of the day.
Carbohydrates
Figure 2.13a–b
Disaccharides- “double sugars” Formed when two
simple sugars are joined by dehydration
synthesis. In this reaction a water molecule is
lost as the bond is formed.
Sucrose is a disaccharide that
consists of both glucose and
fructose linked together.
Dehydration Synthesis- a process by which a
larger molecule is synthesized from smaller
ones by the removal of a water molecule at each
site of bond formation.
Carbohydrates
Figure 2.14
Important Disaccharidessucrose (glucose-fructose)-cane sugar
lactose (glucose-galactose)-milk sugar
maltose (glucose-glucose)-malt sugar
Since double sugars are too large to pass across
cell membranes they are broken down
(digested) to monosaccharide units. This is
accomplished by hydrolysis.
Galactosemia (galactos =milk, -emia
=in the blood)
An disorder in which galactose builds up in
the blood due to the body’s lack of the
enzyme that converts galactose to
glucose. What would you suggest for
treatment for an infant that had this
disorder? (Hint: think about where
galactose comes from…)
No Lactose!!!!
Hydrolysis-the process in which water is used to
split a substance into smaller particles.
Sucrose is the
substrate.
Sucrase is the enzyme responsible
for digesting sucrose.
SUBSTRATE-a substance on which an enzyme reacts during a
chemical reaction. In this case sucrase slightly changes the sucrose weakening the
chemical bonds between the glucose and fructose allowing the sucrose to break apart and be
digested.
Polysaccharides- “many sugars”. Long branching
chains of linked simple sugars. Polysaccharides
are large insoluble molecules that are ideal
storage products. Carbohydrates provide a
ready easily usable source of food energy for
cells. Polysaccharides are long polymers
consisting of up to hundreds of glucose
molecules.
Carbohydrates
Figure 2.13c
Starch-the storage polysaccharide formed by plants. We
ingest it in the form of starchy foods like grains and root
vegetables.
Glycogen-a polysaccharide found in animal tissues
(primarily in the muscles and the liver).
Endoplasmic Reticulum
Shown Here: liver cells where smooth ER helps to metabolize stored glycogen (black rosettes) and metabolize toxic substances.
Figure 2.13c
Lipids (18 – 25% of body mass)
– Contain carbon, hydrogen, and oxygen
• Carbon and hydrogen outnumber oxygen. (ex:
Tristearin is a triglyceride that forms the principle
fat in beef. (C57H110O6)
Lipids
Insoluble in water (non-polar molecules), but
readily dissolve in other lipids and organic
solvents such as alcohol.
• Common lipids in the human body
– Neutral fats (triglycerides)
• Found in fat deposits
• Composed of fatty acids and glycerol
• The body’s most abundant source of stored
energy. Found in fat deposits in subcutaneous
tissue and around organs.
The synthesis of triglycerides involves the attachment of three fatty acids to a glycerol
molecule forming an E-shaped molecule. Molecules vary as the fatty acids change.
Lipids
Figure 2.17
• Saturated vs. Unsaturated Fatty Acids
Saturated-single covalent bonds, straight chain,
which packs tightly together forming a solid at
room temperature.
Unsaturated-double covalent bonds cause fatty
acid chains to kink forming a liquid at room
temperature.
• Trans Fat-oils that have been solidified by
addition of hydrogen atoms at sites of
double carbon bonds.
Phospholipids
• Form cell membranes
• Similar to triglycerides except that a phosphate
group replaces one of the fatty acid chains.
Lipids
Figure 2.15b
Phospholipids
Since the phosphorous containing head bears
an electrical charge a phospholipid has
unique chemical properties that enable the
control of materials into and out of the cell.
(amphipathic: amphi = on both sides)
Steroids-flat molecules composed of four
interlocking rings. Include cholesterol, bile salts,
vitamin D, and some hormones
Testosterone
• Cholesterol
– The basis for all steroids made in the body.
Cholesterol is found in cell membranes and is
the raw material of Vitamin D, steroid
hormones, and bile salts.
Figure 2.15c
• Other Lipids Table 2.7
a)
Carotenes – visual pigments
b)
Vitamin E – wound healing
c)
Vitamin K – Blood clotting proteins
d)
Lipoproteins - transportation of lipids in
blood
• Proteins
– Made of amino acids
• Contain carbon, oxygen, hydrogen, nitrogen, and
sometimes sulfur
Figure 2.16
• Proteins
– Amino Acid Structure-there are about 20
common amino acids that make up proteins
they have the basic structure seen below.
Figure 2.16
• Proteins
– Amino acids are joined together during protein
synthesis to form large complex protein
molecules containing from 50 to thousands of
amino acids.
Figure 2.16
Proteins (12 -18% of body mass)
• Account for over half of the body’s organic
matter
– Provide construction materials for body
tissues
– Play a vital role in cell function
• Act as enzymes, hormones, and
antibodies
Protein Structure
• Primary Structure – unique sequence
of amino acids; genetically determined
• Secondary Structure – repeated
twisting or folding of neighboring amino
acids in the polypeptide chain; alpha
helixes (spirals) or pleated sheets;
stabilized by hydrogen bonds
• Tertiary Structure – three dimensional
shape of the polpeptide chain; unique
tertiary structure to each protein
(enzyme function)
• Quarternary Structure – arrangement
of individual polypeptide chains relative
to one another; only seen in some
proteins
Proteins
• Fibrous proteins
– Also known as
structural proteins
– Appear in body
structures
– Examples include
collagen and keratin
– Stable
Figure 2.17a
Collagen-the protein of bones, cartilage, and
tendons (and plastic surgery ).
Figure 2.17a
Collagen-
Figure 2.17a
Keratin-the protein of hair and nails. Also makes
skin tough.
Figure 2.17a
Proteins
• Globular proteins
– Also known as
functional proteins
– Function as antibodies,
hormones, or enzymes
(regulatory,
immunological,catalytic
,transport, contractile)
– Can be denatured
Figure 2.17b
Globular proteins are unstable and can be easily
denatured. Changes in heat or pH levels can
result in the breaking of hydrogen bonds,
known as denaturing. (NOTE: we don’t KILL
proteins!!!)
Figure 2.17b
When proteins denature their 3-Dimensional
structures are destroyed and can no longer
perform their physiological roles as the shape of
active sites are changed.
Figure 2.17b
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Sucrose is the
substrate.
Sucrase is the enzyme responsible
for digesting sucrose.
SUBSTRATE-a substance on which an enzyme reacts during a
chemical reaction. In this case sucrase slightly changes the sucrose weakening the
chemical bonds between the glucose and fructose allowing the sucrose to break apart and be
digested.
Enzymes act as biological catalysts by
increasing the rate of chemical reactions
http://www.kscience.co.uk/animations/anim_2.htm
Only small amounts of enzymes are required in the
body as enzymes are not consumed during their
reactions. Enzymes are categorized by the type of
reaction that they catalyze ie:
hydrolases add water
oxidases cause oxidation
Figure 2.18a
Galactosemia (galactos =milk;
esemia =in the blood)
• An inherited disorder in which
galactose is not metabolized due
to a faulty or missing enzyme
• Infants fail to thrive within week
after birth due to anorexia,
vomiting and diarrhea
• If Lactose undergoes
hydrolysis to form galactose
and glucose, what would
you suggest for
treatment???
• Nucleic Acids
– Provide blueprint of life
– Nucleotide bases
•
•
•
•
•
A = Adenine
G = Guanine
C = Cytosine
T = Thymine
U = Uracil
– Make DNA and RNA
Figure 2.19a
Nucleic Acids
• Deoxyribonucleic
acid (DNA)
– Organized by
complimentary
bases to form
double helix
– Replicates before
cell division
– Provides instructions
for every protein in
the body
Figure 2.19c
Adenosine Triphosphate (ATP)
Figure 2.20a
Adenosine triphosphate (ATP) the chemical
energy used by all cells. Glucose is the main
source of energy for cells; however the energy
stored in its bonds can’t be used by cells. Our
bodies catabolize glucose and capture and store
the energy in the bonds of ATP.
The energy in ATP is released by breaking high
energy phosphate bond
– ATP is replenished by oxidation of food fuels
Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Energy liberated during
oxidation of food fuels
used to regenerate ATP
Figure 2.21
Membrane
protein
P
Solute
(a) Transport work
ATP
Figure 2.21, step 1
Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ATP
ADP
+
P
Figure 2.21, step 2
ATP
Relaxed
muscle cell
(b) Mechanical work
Figure 2.21, step 3
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
Figure 2.21, step 4
ATP
X
P
+ Y
Reactants
(c) Chemical work
Figure 2.21, step 5
ADP
+
P
ATP
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Figure 2.21, step 6
Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Figure 2.21, step 7
Membrane
protein
P
P
Solute
Solute transported
(a) Transport work
ADP
+
P
ATP
Relaxed
muscle cell
Contracted
muscle cell
(b) Mechanical work
P
X
P
X
Y
+ Y
Reactants
Product made
(c) Chemical work
Energy liberated during
oxidation of food fuels
used to regenerate ATP
Figure 2.21, step 8