Proteins Flashcards
Linear polymers of AA
Proteins
Provide structural framework
Protein
Component of immune system
Protein
Set of all the chons expressed by an individual cell at a particular time
Proteome
How many AA are commonly found in mammalian chon
20
Each amino acid has carboxyl group, amino group, distinctive side chain (called R-group)
Proline
Dictates function of AA in a chon
R-group
No H bond
Nonpolar AA
Non polar amino acids
Glycine Alanine Valine Isoleucine Leucine Phenylalanine Tryptophan Methionine Proline
Polar uncharged amino acids
Serine Threonine Tyrosine Cysteine Asparginine Glutamine
Amide
Asparginine
Glutamine
Charged amino acids
Found on the surface chon
Aspartate Glutamate Arginine Lysine Histidine
Has the smallest side chains
Glycine
Used in 1st step in heme synthesis
Glycine +
Succinyl coA
= delta ALA
Glycine is used in synthesis of
Purines and creatinine
Major inhibitory NT of spinal cord
Glycine
Carrier of ammonia
Alanine
Branched chain AA; accumulate in maple syrup dse
Valine
Leucine
Isoleucine
Accumulate in phenylketonuria
Phenylalanine
Precursor of tyrosine
Phenylalanine
Has largest side chain
Tryptophan
tryptophan precursor to
Melatonin
Serotonin
Niacin
Vitamin B3
Niacin
Happy hormone
Serotonin
Precursor of homocysteine
Methionine
Imino acid
Proline
Contributes to fibrous structure of collagen
Intereupts a-helices in globular proteins
Proline
Serine, threonine, tyrosine
Site for
O linked glycosylation
Tyrosine
Precursor of
Phenylalanine Tyrosine L dopa Dopamine Norepinephrine Epinephrine
Precursor for thyroxine and melanin
Tyrosine
Have a carbonyl group and amide group
Asparagine, glutamine
Site for n linked glycosylation
Asparagine
Glutamine deaminated by
Glutaminase
Glutamine deaminated will form
Ammonia
Major carrier of nitrogen from peripheral tissue to liver
Glutamine
Contain sulfhydyl group
Cysteine
Participates in biosynthesis of coenzyme A
Cysteine
Present in hair
Keratin
Contains a lot of cystine
What are the acidic AA
Aspartate
Glutamate
Serves a proton donors
Aspartate
Glutamate
Precursor of GABA
and glutathione
Glutamate
What are the basic AA
Histidine
Arginine
Lysine
They are proton acceptors
histidine
Arginine
Lysine
Precursor of histamine
Histidine
Dx of folic acid def
FIGlu excretion test
AA used in FIGlu excretion test
Histidine
Precursor of creatinine
Urea
Nitric oxide
Arginine
Present in lathyrus seeds
Homoarginine
B-ODAP
Implicated in neurolathyrism
Homoarginine
B-ODAP
Neurotoxic aa in cycad seeds; implicated in ALS-parkinson dementia complex
B-methylaminoalanine
All aa are chiral except
Glycine
All aa in chons
L-configuration
Bacterial cell walls, antibiotics
D-configuration
10 essential aa
Isoleucine Leucine Threonine Valine Methionine Arginine Phenylalanine Tyrosine Lysine Histidine
Stepwise process of identifying the specific aa at each position in peptide chain
Sequencing
Mc 2ndry structure
Alpha helix
Alpha helix is disrupted by
Proline
Keratin, hgb
Are example of
Alpha helix
Aa residues form a zigzag pleated pattern
Beta sheet
Amyloid
Immunoglobulin
Are example of
Beta sheet
Fundamental functional and 3 dimensional structural units of polypeptide
Domains
Required for the proper folding of many species of chons
Chaperones
Results in unfolding and disorganisation of chon’s 2ndry and tertiary structure
Denaturation
Hyperbolic o2 dissociation curve
Myoglobin
Sigmoidal o2 dissociation curve
Hemoglobin
Factors that causes a shift to the right
Increase co2, acidity (dec ph)
Inc 2,3 BPG, exercise, tempt
The release of o2 from
Hgb is enhanced when the pH js lowered or when hgb is in presence of an inc
Pco2
Bohr effect
Has increased affinity for oxygen
FEtal hemoglobin
Form of hgb bound to CO in place of o2
Carboxyhgb
200x greater affinity for hgb than o2
CO
Hb becomes cherry pink
Carboxyhgb
Tx of CO toxicity
100% o2 therapy
Chocolate cyanosis
Methemoglobinemia
Tx for methemoglobinemia
Mild
Ingestion
Mild: oral methylene blue or ascorbic acid
Ingestion: IV methylene blue
MC mutation in hereditary spherocytosis
Ankyrin
Results from a point mutation in both genes coding for Bchain that results in valine rather than glutamate
Sickle cells dse
Has single amino a id substitution in 6th position of Bglobin in wc lysine is substituted for glutamate
Hgb C dse
Accumulation of Hb Bart and Hb H and Bchain precipitation
Alpha thalassemia
Thalassemia
Symptoms appear at birth
Alpha T
Thalassemia
Physical manifestations appear only after birth
beta thalassemia
Most abundant protein in the body
Collagen
Mc form of collagen
Type 1
Type of collagen
Bone
I
Type of collagen
Cartilage
II
Type of collagen
Reticulin - skin, BV, granulation tissue
III
Type of collagen
Basement membrane
Basal lamina
IV
Type of collagen
Beneath stratified squamous epith
VII
Mc Ehlers dais syndrome
Hyper mobility
Defect in type 3
Most serious Ehlers danlos
Vascular
Type 3 defect
Aka brittle bone syndrome
Osteogenesis imperfecta
Blue sclerae
Hearing loss
Osteogenesis imperfecta
Disorder jn type 4 collagen
Alport syndrome
Renal
Disorder of type 7 collagen
Epidermolysis Bullosa
Characterized by
Kinky hair, growth retardation
Menkes dse
Deficiency in copper dietary
Menkes dse
Dolichostenomelia
Arachnodactyly
Ectopia lentis
Marfan syndrome
Hyperbolic o2 dissociation curve
Myoglobin
Sigmoidal o2 dissociation curve
Hemoglobin
Factors that causes a shift to the right
Increase co2, acidity (dec ph)
Inc 2,3 BPG, exercise, tempt
The release of o2 from
Hgb is enhanced when the pH js lowered or when hgb is in presence of an inc
Pco2
Bohr effect
