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GLYCINE
1
...


Not chiral bcz of absence of 4 different groups as side chains
Has only H group on side chains therefore
--can be fit into hydrophobic and hydrophilic environments
--can adopt phi and psi angles in all 4 quadrants of ramachandran plot
!
Therefore get conformational stability
!
Occur in regions of turns Ex- Collagen(35% Glycine)
--rest proteins has less glycine except collagen
--- can bind to phosphates

3
...


coded by codons GGU, GGC, GGA and GGG

ambivalent

SYNTHESIS



Not biosyntesized in body
From serine

In most organisms, the enzyme serine hydroxymethyltransferase catalyses this transformation via the
cofactor pyridoxal phosphate:
serine + tetrahydrofolate → glycine + N5,N10-Methylene tetrahydrofolate + H2O
In the liver of vertebrates, glycine synthesis is catalyzed by glycine synthase

This conversion is

readily reversible:
CO2 + NH4+ + N5,N10-Methylene tetrahydrofolate + NADH + H+ → Glycine + tetrahydrofolate +
NAD+

DEGRADATION
3 pathways----

in animals and plants involves the glycine cleavage enzyme
Glycine + tetrahydrofolate + NAD+ → CO2 + NH4+ + N5,N10-Methylene tetrahydrofolate + NADH
+ H+
------

In the second pathway, glycine is degraded in two steps
1st step- reverse of glycine biosynthesis from serine with serine hydroxymethyl transferase
...
[14]
-----In the third pathway of glycine degradation,
glycine is converted to glyoxylate by D-amino acid oxidase
...


FUNCTIONS:
1
...


2
...


3
...
as a sweetener/taste enhancer
2
...
serves as a buffering agent in antacids, analgesics, antiperspirants, cosmetics, and
Toiletries
...
significant component of some solutions used in the SDS-PAGE
--serves as a buffering agent, maintaining pH and preventing sample damage during
electrophoresis
...
This allows more data to be drawn from
the same specimen, increasing the reliability of the data, reducing the amount of sample processing,
and number of samples required
...


ALANINE
1
...
a non-polar amino acid
...
It is ambivalent, meaning that

it can be inside or outside of the protein

molecule
4
...

6
...


L-Alanine is second only to leucine in rate of occurrence
...

classified as an aliphatic amino acid
...


Biosynthesis


in the body from pyruvate and branched chain amino acids such as valine, leucine, and
isoleucine
...
Glucose–alanine cycle
2
...
Free radical stability
The deamination of an alanine molecule produces a stable alkyl free radical,
CH3C•HCOO–
...
codons are GUU, GUC, GUA, and GUG
2
...
Aliphatic R-group
4
...
usually found in the interior of proteins
...
In sickle-cell disease, valine substitutes for the hydrophilic amino acid glutamic acid
in hemoglobin
...

7
...


Biosynthesis



Valine is an essential amino acid, hence it must be ingested, usually as a component of proteins

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