finals - proteins Flashcards
protein came from a greek word __
proteis
Protein comes from the greek word proteis, meaning___
“first rank of importance.”
proteisn are synthesized in the __and secreted by the hepatocyte into the circulation except immunoglobulins (plasma cells).
liver
amino acids are protein’s building block, how do amino acids are linked together
covalently
Proteins can bear positive and negative charges which means they are __
amphoteric
They can be both a weak base or weak acid, hence,
proteins are effective ___.
blood buffers
longer chain but lower than 1 k chains
oligopeptide
1k chain
polypeptide
protein’s solubility is due to ___
high dielectric property
They are very effective antigens due to their
___.
molecular mass, tyrosine content and their specificity
They provide __of the total daily body energy
requirement.
12 to 20%
Proteins are ____% of the cell’s dry weight
50% to 70
elements of protein
CHO - N
additional elements of protein aside from CHON
sulfur, iron, phosphorous, and other metals
It is the fact that proteins contain __ that sets
them apart from pure carbohydrates and lipids, which
do not contain nitrogen atoms
nitrogen
The nitrogen content of serum protein is, on average,approximately __
16%.
This measurement of ___ is used in one
method for total protein
nitrogen content
a type of technique that measures Nitrogen that is directly proportional to the concentration of the total protein in the body
kendal daw
Most versatile molecules in our bodies
proteins
how many different proteins exist in our bodies
10,000-50,000
Amino Acids are large molecules that is why they are termed as
macromolecules
Fundamental building blocks of all proteins
Amino Ac
Electric charge depends on __
pH of the solution and type of R group
amine group elements
NH2
carboxyl group elements
COOH
amine group and carboxyl group is held together by
chiral carbon
the group which is responsible for the specificity of amino acid
r group
electric charge of basic or carboxylic group
negative
electric charge of acidic or amine group
positive
Basic solution – (-) charge, proton ___ from the
carboxyl group present forming COO
dissociate
Acid solution excess of protons (H+) which can attach to NH2 group to form ___
NH3+
These charges affect how each protein moves in an ___ -
electric field
the movement of proteins are based on
electric charges
it allow us to separate proteins based on the electric charges
SPE - serum protein electrophoresis
Both (+) and (-) charges may exist on the same
molecule
Zwitterion
netcharge of Zwitterion
neutral or 0
sum of molecules
charges equals zero.
isoelectric point
normal pH of protein is
5.5 - 8
once the protein is subjected to SPE the solution’s pH must be
8.6
Functions of proteins
- Repair body tissues
- Important in blood coagulation and immunologic function
- For transport of metabolic substances
- Maintenance of osmotic pressure
- Maintenance of blood pH (buffers)
- Biocatalysts
in coagulation process, proteins are made up of
serine proteases
term referred to space inside the vessel
intravascular space
term referred to space outside the vessel
extravascular
extravasation of blood fluid
edema
Four Structures of Proteins
Primary Structure
Secondary Structure
Tertiary Structure
Quaternary Structure
It is the linear sequence of the amino acid.
. Primary Structure
It determines the Identity of protein, molecular
structure, function binding capacity and recognition
ability.
Primary Structure
Any change in the amino acid composition can
significantly alter the protein.
Primary Structure
It involves the winding of the polypeptide cha
. Secondary Structure
It refers to specific 3-dimensional conformations -
alpha helix, beta pleated and bend form
Secondary Structure
How the protein chain twists and bends along its
length
alpha helix
beta pleated sheet
random
Secondary Structure
coil, resembling a spring
alpha helix
Secondary Structure
flat, corrugated structure
beta pleated sheet
Secondary Structure
no apparent pattern
random
It is the actual 3-dimensional configuration, the folding
pattern of the protein.
tertiary Structure
It is responsible for many of the physical and chemical
properties of the proteins.
Tertiary Structure
It is maintained by electrovalent linkages, hydrogen
bonds, disulfide bridges, Van der Waals forces and
hydrophobic interactions.
Tertiary Structure
It is the association of 2 or more polypeptide chains to form a functional protein molecule.
Quaternary Structure
Example of quaternary structure h
hemoglobin, LDH, CPK
lactate dehydrogenase
creatinine phosphokinase
Classes of Proteins according to Functions
- Enzymes
- Structural proteins
- Contractile proteins
- Antibodies
- Transport proteins
- Peptide hormones
a transport protein that has no quarternary structure - single polypeptide
Albumin
are those that generate
precursors of glucose such as pyruvate or citric acid
cycle intermediates.
Glucogenic amino acids
are degraded to acetyl-CoA
such as leucine or lysine.
Ketogenic amino acids
how do we able to convert amino acids to glucose
gluconeogenesis
Example of glycogenic amino acid:
alanine (pyruvate),
arginine (a- ketoglutarate),
aspartate
Classification of Proteins according to Fu
Simple Protein
Conjugated Proteins
2 types of simple proteins
fibrous or globular
They contain peptide chains which on hydrolysis yield
only amino acids.
Simple Proteins
example of fibrous simple protein
fibrinogen, collagen
example of globular simple protein
hemoglobin, plasma proteins, peptide
hormones
are compact and have
little or no space for water in the interior of the molecule; they retain their biological activities within
narrow ranges of temperature and pH.
globular proteins
These are composed of a protein (apoprotein) and a
non-protein moiety (prostheticgroup).
Conjugated Proteins
the protein part of conjugated protein is calld as
apoprotein
the nonprotein part of conjugated protein is calld as
prosthetic group
a conjugated proteins
example of Metalloproteins
ferritin,
hemoglobin and flavoproteins
a conjugated proteins
example of Lipoproteins
VLDL, HDL, LDL, chylomicrons
a conjugated proteins
example Glycoproteins
haptoglobin, ar-antitrypsin (with
10%-40% CHO)
a conjugated proteins
example Mucoproteins or proteoglycan
mucin (higher
CHO content than CHON)
a conjugated proteins
example Nucleoproteins
chromatin
is a balance between anabolism
(synthesis) and catabolism
Nitrogen balance
It is when a protein catabolism
exceeds anabolism
Negative nitrogen balance
It is characterized by excessive
tissue destruction such as burns,
wasting disease, high fever and
starvation
Negative nitrogen balance
It is when anabolism is greater than
catabolism
Positive nitrogen balance
Positive nitrogen balance example are
growth, pregnancy and
repair processes
It migrates ahead of albumin
Prealbumin
Prealbumin alias
Transthyretin
It is rich in tryptophan and contains 0.5%
carbohydrate.
Prealbumin (Transthyretin
t4 alias
Thyroxine
half life of pre albumin
2 days
secondary structure of pre albumin
B-pleated sheet conformation
Prealbumin (Transthyretin) aliases
retinol-binding protein.
thyroxine binding globulin
It is used to detect malnutrition and individual’s
response to dietary supplementation
Prealbumin (Transthyretin
It is used as landmark to confirm that the specimen is
really CSF it crosses more easily into the CSF than
other proteins
Prealbumin (Transthyretin)
Prealbumin (Transthyretin) increased in
alcoholism, chronic renal failure, steroid
treatment
Prealbumin (Transthyretin in Decreased
poor nutrition
ref value of pre albumin
18-45 mg/dl :
Conversion factor: 10-
mg/L
retinol is also known as Vit ___
A – VITAMIN A
