small detail on some products. AMINO ACIDS 1 Porphyrins 2 Neurotransmitters 3 Hormones 4 Purines 5 Pyrimidines

1. BY HIJAB SIDDIQI

2. Amino acids in addition to serving as building
blocks for proteins also serves as precursors of
many nitrogen-containing compounds that have
important physiologic functions.
These molecules include
1. Porphyrins
2. Neurotransmitters
3. Hormones
4. Purines
5. Pyrimidines

3. Porphyrins: Porphyrins are cyclic compounds that readily bind
metal ions - usually Fe2+ or Fe3+.
Neurotransmitters: Neurotransmitters are those compounds which
transmits nerve impulse from one neuron to other
Hormones: Hormones are body’s chemical messengers. They can be
either endocrine or exocrine in nature.
Purines: Nucleotides are composed of a nitrogenous base, one of these
family compound is purine.
Pyrimidines: Nucleotides are composed of a nitrogenous base, one of
these family compounds is pyrimidines

4. EXAMPLES OF

5. The most prevalent metalloporphyrin in humans is heme,
which consists of one ferrous (Fe2+) iron ion coordinated in
the center of the tetrapyrrole ring of proto porphyrin IX.
Heme is the prosthetic group of
 Hemoglobin
 Myoglobin
 Cytochromes
 Catalase
 Nitric oxide synthase
 Peroxidase
These heme proteins are rapidly synthesized and degraded.
Coordinated with the turn over of heme proteins is the
simultaneous synthesis and degradation of the associated
porphyrins and recycling of the bound iron ions.

7. EXAMPLES OF

8. Dopamine, norepinephrine, and epinephrine are biologically
active (biogenic) amines that are collectively termed
catecholamines. Dopamine and norepinephrine are synthesized in
the brain and function as neurotransmitters. Norepinephrine is also
synthesized in the adrenal medulla, as is epinephrine.
FUNCTION:
Outside the nervous system the caecholamines are hormones
regulator for carbohydrate and lipid metabolism.
Norepinephrine and epinephrine are released from storage vesicles
in the adrenal medulla in response to fright, exercise, cold, and
low levels of blood glucose. They increase the degradation of
glycogen and triacylglycerol, as well as increase blood pressure
and the output of the heart. These effects are part of a coordinated
response to prepare the individual for stress, and are often called
the “fight-or-flight” reactions.

10. EXAMPLES OF

11.  Insulin is a polypeptide hormone produced by the
β cells of the islets of Langerhans.
 Its metabolic effects are anabolic.
 Insulin is composed of 51 amino acids arranged in
two polypeptide chains, designated A and B.
 Insulin secretion is increased by
1. Glucose
2. Amino acids
3. Gastrointestinal hormones

12.  Glucagon is a polypeptide hormone secreted by the α
cells of the pancreatic islet of Langerhans.
 Glucagon, along with epinephrine, cortisol, and
growth hormone opposes many of the actions of
insulin.
 Glucagon acts to maintain blood glucose levels by
activation of hepatic glycogenolysis and
gluconeogenesis.
 Glucagon is composed of 29 amino acids arranged in a
single polypeptide chain.
 Glucagon is stimulated by:
1. Low blood glucose
2. Amino acids
3. Epinephrine

14. EXAMPLES OF

15. Purines include:
 Adenine “A”
 Guanine ‘G”
Adenine is 6-aminopurine.
Guanine is 2-amino,6-hydroxypurine. Guanine
occurs in two forms, enol and keto: in the later
form it is 2-amino,6-oxypurine.

17. EXAMPLES OF

18. Pyrimidine includes:
 Cytosine “C”
2-hydroxy,4-aminopyrimidine
 Uracil “U”
2,4 dihydroxypyrimidine
 Thymine “T”
5-methyl uracil
Pyrimidines can occur in both keto (lactam) and
enol (lactim) forms.
Above given forms are lactim forms.

20.  Lipincott’s illustrated review Biochemistry
 Essentials of Medical Biochemistry vol.I
 Pictures are taken from following adresses
1. http://upload.wikimedia.org/wikipedia/commons/9/9f/Blausen_0323_DNA_Purin
es.png
2. http://upload.wikimedia.org/wikipedia/commons/3/38/Purine.png
3. http://images.tutorvista.com/cms/images/81/pyrimidine.png
4. http://wellnessadvocate.com/images/Structural_Formulas/Pyrimidine_Skeleton.gi
f
5. https://chiropracticplusmtcom.chiromatrixbase.com/clients/5272/images/synapse
_1[1].png
6. http://departments.colgate.edu/chemistry/images/geier-fig1.gif
7. http://upload.wikimedia.org/wikipedia/commons/thumb/5/5c/Porphyrin.svg/200p
x-Porphyrin.svg.png
8. http://biology-igcse.weebly.com/uploads/1/5/0/7/15070316/7448993_orig.png
9. http://people.upei.ca/bate/assets/images/p10.gif
10. http://mybrainnotes.com/dopamine-norepinephrine-epinephrine.gif