[2S] UNIT 5.1: Proteins & Amino Acids Flashcards
Catalytic site in proteins and enzymes
Semi-essential
Dietary supplementation
required in youth
Arginine
Cell division
Wound healing
Stimulation of protein synthesis
Immune function
Release of hormones
Conversion of ammonia (NH3) to urea
Arginine
NH2 R-Group
Arginine
Grow and repair body tissues
Maintains myelin sheaths
Direct precursor of Histamine
o Decarboxylationrxn
o Enzyme: Histidine decarboxylase
Histidine
Maintains normal body pH 7
Manufacturing RBCs and WBCs
Protection from heavy metal toxicity*
Source of carbon atoms in purine synthesis
Histidine
Imidazole side chain (Basic)
Histidine
For infant growth
Leucine
Treatment for muscle, mental, and emotional problems
o Insomnia
o Anxiety
o Liver disease
o Gall bladder disease
Valine
Healing of muscle tissue, bones, and skin
Regulates blood glucose
Maintains nitrogen balance in adults
Val, Isoleucine, Leucine
Hgb formation
Isoleucine
Branched chain amino acid group
Val, Isoleucine, Leucine
Net positive charge
Basic amino acid
Lysine
Production of antibodies
Lower triglyceride levels
Absorption and conservation of Ca+
Formation of collagen (via conservation of Ca)
Lysine
First AA incorporated into the N-terminal position of all proteins
Source of sulfur
Initiates mRNA translation
Methionine
Non-polar AA
Direct precursor of metabolic Tyrosine
Phenylalanine
Assists breakdown of fats
Detoxifying lead and other heavy metals*
Diminish muscle weakness
Prevents brittle hair (shampoo)
Reacts with ATP in the synthesis of epinephrine and choline
Methionine
Alertness and vitality
Elevates mood
Decreases pain
Aids in memory and learning
Treats arthritis and depression
Blood brain barrier
Norephinephrine production
Phenylalanine
Large quantities interfere with serotonin production
Deficiency causes mental retardation in infants
Phenylalanine
- Alcohol containing AA
- Formation of collagen, elastin, and tooth enamel
Threonine
Production of neurotransmitters
Maintain protein balance
Aids in liver function, metabolism, and assimilation
Threonine
Simple amino acid
Product of DNA or dipeptide (anserine and carnosine) breakdown
Formed from glycolysis in the muscle tissue and pyruvate conversion
Alanine
Metabolic precursor for serotonin, melatonin, and niacin
Tryptophan
Alleviates insomnia by inducing sleep
Soothes anxiety
Reduces depression
Treats migraine and headache
Reduces appetite (weight control)
Controls hyperactivity in children
Tryptophan
- Gluconeogenesis
- Synthesis of some AA: Threonine, Isoleucine, Lysine, Meth, Asparag, Arginine
Aspartic Acid
Derived from aspartic acid and ATP through transamidation
Most abundant AA
Amination or Transamination
o Converts one amino acid to another
Asparagine
Transfer nitrogen from peripheral tissues to liver
Strengthen immune system
Reduces buildup of toxic substances from muscle protein breakdown
Alanine
Synthesis of ammonia (NH3)
Transport of nitrogen
Asparagine
Synthesized from oxaloacetate through transamination
Metabolite in the citric acid cycle and urea cycle
Negatively charged (-COOH side chain)
Aspartic Acid
Toxic
Absorbed during digestion as cystine
Cysteine
can be synthesized from Methionine through enzymatic rxns
Cysteine
Structural and functional component of proteins and enzymes
Antioxidant
Cysteine
Net negative charge (- COOH side chain)
o carboxylic groups = acidic
Polar molecule
Synthesized from
transamination of alanine and aspartic acid
Forms Glutamine
Glutamate
Neurotransmitter
Dysregulation linked to
epileptic seizures
Metabolism of sugars and fats
Transport of K+ into spinal fluid
Glutamate
Most abundant amino acid
Synthesized from the addition of amino group to glutamate
Glutamine
Wound healing
Connective tissue repair
Proline
Produced from glutamine
Precursor for hydroxyproline
Works in tandem with Vit C
Proline
Transport ammonia to liver for metabolism
Renal maintenance of acid-base balance
Source of cellular energy Aids in immune function
and digestive tract health Treatment of serious illnesses, injury, trauma,
burns, cancer treatment
Wound healing for post-
operative patients
Glutamine
Synthesized from 3- phosphoglycerate (an intermediate in glycolysis)
Highly concentrated in all cell membranes
Component of myelin
sheaths
Serine
manufactured into collagen, tendons, ligaments, and cardiac tissue
hydroxyproline
Production of antibodies
Metabolism of lipids and fatty acids
Body synthetic pathways for pyrimidine, purines, creatines, and porphyrins
Serine
Synthesized from Phe
Precursor of adrenal hormones
Tyrosine
Overall metabolism and function of adrenal glands, thyroid, and pituitary glands
Stimulates nervous system metabolism (mood elevator)
Treats narcolepsy, anxiety, depression, allergies, and headaches
Tyrosine
Present in enzymes, such as formate dehydrogenases, glycine reductases, and some hydrogenases
HIV diagnosis and monitoring
SELENOCYSTEINE
21st amino acid
Encoded by a UGA codon (stop codon)
Selenium analog of cysteine – selenium atom replaces the sulfur
SELENOCYSTEINE
T/F: Patients with HIV infection have lower-than-average blood plasma
selenium level
T
22nd amino acid
Encoded by the UAG codon
NOT PRESENT IN HUMANS
Natural occurring genetically encoded amino acid used by some of the
prokaryotes and single-celled microorganisms
PYRROLYSINE
Methane-producing metabolism in prokaryotes and single-celled microorganisms
PYRROLYSINE
AMINOACIDOPATHIES
Phenylalanine hydroxylase (PAH) deficiency
PAH cannot catalyze the conversion of
Phenylalanine -> Tyrosine
Leads to phenylalanine accumulation
PHENYLKETONURIA (PKU)
AMINOACIDOPATHIES
Chronic elevation: permanent brain damage
Found in both blood and urine of patients
Musty / mousy urine odor
Maternal phenylketonuria
microcephalic mentally retarded infants
PHENYLKETONURIA (PKU)
AMINOACIDOPATHIES
PKU treatment
Sapropterin dihydrochloride (Kuvan)
AMINOACIDOPATHIES
Bacterial inhibition assay
Based on the ability of Phe to facilitate bacterial growth in a culture medium in the presence of a growth inhibitor
Can detect serum Phe
Concentrations of 180 umol/L
(3 mg/dL)
PKU: Guthrie Test
AMINOACIDOPATHIES
Not affected by the presence of antibiotics
Based on the fluorescence of phenylalanine, ninhydrin and copper complex
PKU: Microfluorometric Assay
AMINOACIDOPATHIES
PKU ref method
High-Performance Liquid Chromatography
AMINOACIDOPATHIES
Elevated tyrosine blood concentration and succinylacetone concentration
o Succinylacetone: toxic metabolite; forms due to tyrosine accumulation
Body cannot metabolize Tyrosine
Leads to Tyrosine accumulation
ALKAPTONURIA
TYROSINEMIA