LIPIDS PART 2 Flashcards
Small biomolecules containing at least one amino
group and one carboxyl group bonded to the
alpha-carbon
amino acid
three parts of amino acids:
○ Amino group
○ Carboxylic acid group
○ Sidechain or R group
■ The carbon at the center
■ It is named such because it is the
first carbon atom attached to the
functional groups and the side
chain
Alpha Carbon
2 uncommon amino acids:
selenocysteine and pyrrolysine
Amino acids can be classified according to the
polarity of their side chains:
Non-polar hydrophobic
Polar and uncharged
Polar and charged
Polar acidic
Polar basic
■ Their R groups are mostly
Hydrocarbons (CH)
Non-polar hydrophobic
■ Their R groups are Alcohol,
Phenol, Thiol, Amide
Polar and charged
The ___ of the
oxygen are one of the signs that
describes the amino acid as polar
acidic
negative charge
■ Their R group can’t be seen but supposedly, the oxygen has a
negative charge
Polar acidic
■ Instead of having a negative
charge, a positive charge can be
seen its side chains
Polar basic
Nonpolar amino acids (8)
Ala
Val
Leu
Iso
Phenyl
Trypto
Met
Pro
Polar and uncharged amino acids (7)
Gly
Ser
Threo
Cys
Tyr
Asp
Glut
Polar Basic amino acids (3)
Lys
Arg
His
● It is required in the diet = can’t be synthesized by
the body
ESSENTIAL AMINO ACIDS
Polar Acidic amino acids (2)
Aspartic Acid
Glutamic Acid
ESSENTIAL AMINO ACIDS (10)
PVT TIM HALL
○ Phenylalanine
○ Valine
○ Threonine
○ Tryptophan
○ Isoleucine
○ Methionine
○ Histidine
○ Arginine
○ Leucine
○ Lysine
● Not required in the diet = can be synthesized by the
body
NON-ESSENTIAL AMINO ACIDS
NON-ESSENTIAL AMINO ACIDS (10)
AAA CGGG PST
○ Alanine
○ Asparagine
○ Aspartic Acid
○ Cysteine
○ Glutamic Acid
○ Glutamine
○ Glycine
○ Proline
○ Serine
○ Tyrosine
● Plays a role in cell division
● Healing of wounds, stimulation of protein synthesis
● Immune function
● Release of hormones
ARGININE
Required for the generation of urea and
synthesis of creatine
arginine
■ Is a compound involved in the
supply of energy for muscle
contraction
■ Synthesized with arginine
Creatine Phosphate
■ Less toxic form produced from the
ammonia
■ Metabolized in the urea cycle
Urea
creatine when broken down forms ___
creatinine
● Direct precursor of histamine
● Repair body tissues
● Maintain myelin sheaths that protect the nerve cells
● Helps manufacture RBC and WBC
● Protect the body from heavy metal toxicity
HISTIDINE
● Needed for hemoglobin formation
● Helps to regulate blood and glucose levels and
maintain energy levels
ISOLEUCINE
● Boosts healing of muscle, skin, and bones
● Aids in recovery from surgery
● Lowers blood glucose levels
● Optimal growth of infants and for nitrogen
balance in adults
LEUCINE
● Plays a role in the production of antibodies
(immunoglobulins) and lowers triglyceride levels
● Needed for proper growth and bone development
in children
● Maintain a proper nitrogen balance in adults
● Helps in the absorption of calcium and the
formation of collagen
LYSINE
● Helps initiate translation of messenger RNA
○ First amino acid encoded during
translation
METHIONINE
functions for the normal metabolism
and growth of the body
Sulfur
Assist the breakdown of fats
● Helps to detoxify lead and other heavy metals
● Helps diminish muscle weakness
● Prevents brittle hair
methionine
amino acid that is a source of sulfur
methionine
Promotes alertness and vitality, elevates mood,
decreases pain, aids memory and learning
● Used to treat arthritis and depression
● Used by the brain to produce norepinephrine
● Uses active transport channel to cross the BBB
○ BBB: Blood-Brain Barrier
● Interferes with the production of serotonin
PHENYLALANINE
Part of the composition of aspartame
PHENYLALANINE
Made up of phenylalanine & aspartic acid
Common sweetener used in tared foods as
sugar replacement
aspartame
● Important in the component in the formation of
protein, collagen, elastin, and tooth enamel
● Helps maintain proper protein balance and aids in
liver function, metabolism, and assimilation
THREONINE
Stabilized the mood
■ A natural happy chemical = Person feeling happy
Serotonin
■ Hormone secreted by pineal gland
■ Sleep week cycle (highest during
night time
Melatonin
Natural relaxant
● Alleviate insomnia by inducing sleep, soothes
anxiety and reduces depression
● Used in treatment of migraine headaches
● Aids in weight control by reducing appetite
● Helps control hyperactivity in children
● Heaviest among all the amino acids
Tryptophan
serotonin scientific name
5-hydroxytryptamine (5-HT)
● Needed for muscle metabolism and coordination,
tissue repair and maintenance of nitrogen balance
● Used by muscle tissue as an energy source
● Used in treatments for muscle, mental and
emotional problems (insomnia, anxiety, liver and
gallbladder disease)
VALINE
● Involved in the breakdown of glucose
● Product of the breakdown of DNA
● Transfer of nitrogen from the peripheral tissue to
the liver
● Helps in reducing the buildup of toxic substances
that are released into muscle
● Strengthens the immune system through
production of antibodies
ALANINE
● First amino acid to be isolated = From asparagus
juice
● Converting one amino acid into another via
amination and transamination
ASPARAGINE
Processes that occur before urea cycle in asparagine that converts one amino acid to another:
amination
transamination
■ Amino acid is transferred to an
alpha keto acid (alpha
ketoglutarate)
Transamination
■ Amine group is introduced to an
organic molecule
Amination
Required by the nervous system and synthesis of
ammonia
ASPARAGINE
● A.K.A Aspartate
● A metabolite in the urea cycle and participates in
gluconeogenesis
ASPARTIC ACID
■ Metabolic pathway wherein we
produce glucose (pyruvate) from
noncarbohydrate sources
Gluconeogenesis
CYSTEINE
● Named after ___ (precursor)
cystine
cystein is also known as ___
half-cysteine residue
Production of flavors
Contains sulfur
cysteine
2 amino acids with sulfur:
cysteine
methionine
● Serves as a neurotransmitter and dysregulation has
been linked to epileptic seizures
● Aids in transporting potassium to the spinal fluid
● Responsible for the taste umami
● Food additive/food enhancer (sodium salt,
monosodium glutamate (bitsin)
GLUTAMIC ACID (GLUTAMATE)
● Most abundant amino acid in the body
GLUTAMINE
Assists in maintaining the proper acid/alkaline
balance in the body (regulates pH)
● Provides fuel for a healthy digestive tract
Supplement used for muscle growth in weightlifting
and bodybuilding
GLUTAMINE
Transports ammonia to the liver
○ Ammonia is toxic to the body (increased
levels is dangerous), may lead to
comatose
○ Needs to be transported to the liver where
ammonia will be converted to urea
(through the urea cycle pathway)
glutamine
● Simplest amino acid
GLYCINE
Only amino acid not optically active because it has no stereoisomers
glycine
Has a sweet taste and is used as a sweetener
● Inhibitory neurotransmitter in the CNS
● Helps in the synthesis of bile acids
Retards muscle degeneration, improves glycogen storage and promotes healing
GLYCINE
PROLINE
● Precursor of ___
hydroxyproline
Technically not an amino acid, but an imino acid
● Role in wound healing and molecular recognition
● Works with vit. c to promote healthy connective
tissues
● Technically not a protein since it is an imino acid
due to its cyclic structure
○ No amine group = only imino group
proline
● Involved with fats
● Needed for proper metabolism of fats and fatty
acids
● Highly concentrated in all cell membranes
(phospholipid bilayer)
● Component of the protective myelin sheaths
surrounding nerve fibers
○ Myelin sheath contain fats
serine
● Precursor of epinephrine, norepinephrine,
dopamine, t3 and t4
TYROSINE
Stimulates metabolism
● Mood elevator, suppresses appetite and helps
reduce body fat
● Treatment of chronic fatigue, narcolepsy, anxiety,
depression, low sex drive, allergies and headaches
TYROSINE
Thyroid hormones are not purely tyrosine,
it also has ___
-iodine
Encoded by UGA codon
○ UGA is normally a stop codon, however,
like the other amino acids used by cells,
selenocysteine has a special transfer RNA
(tRNA)
SELENOCYSTEINE
selenocysteine is selenium analogue of ___
cysteine
Selenocystein is found in some enzymes like:
○ Formate dehydrogenase
○ Glycine reductase
○ And some hydrogenases
Encoded by UAG codon
PYRROLYSINE
Used by archaea and unicellular organisms
PYRROLYSINE
Normally a stop codon, possibly modified
by the presence of a ___ forcing the incorporation of
pyrrolysine instead of terminating
translation
specific downstream
sequence
Amino acids (especially essential amino acids)
are found in food in the form of
protein
Protein will be initially digested by the
enzymes ___ and ___
pepsin and trypsin
once proteins are degraded, it becomes ___
amino acid
Amino acids will be absorbed in the __
and will become part of the amino acid pool
intestine
■ Where amino acids are acquired
to be used for translation
Amino Acid Pool
Once the body opts to degrade the amino
acid, the product of degradation will vary
depending on if the amino acid is ___ or
___
ketogenic
glucogenic
Acetyl-CoA → Can enter
___ or will be allowed to
enter the ___
ketogenesis, citric acid cycle
■ Generate precursors of glucose or pyruvate
Glucogenic Amino Acids
■ When degraded = produce either
Acetoacetyl-CoA/Acetyl-CoA
Ketogenic Amino Acids
Acetoacetyl-CoA → Can be
converted to ___ or can
be used in __
Acetyl-CoA, ketogenesis
pyruvate from glucogenic amino acids can become
proceed gluconeogenesis or become actetyl-CoA and enter citric acid cycle
aside from pyruvate, products of other glucogenic amino acids become ___ which will then be part of the citric acid cycle
citric acid cycle intermediate
An amino group is removed from amino acid through ___
oxidative deamination or transamination
products of oxidative
deamination or transamination
ketoacid (usually
a-ketoglutarate)
and ammonia)
■ Enter the common metabolic
pathway
Keto Acid
product of oxidative deamnation that is toxic = converted to urea (less toxic form) through the urea cycle
Ammonia
ketogenic amino acids (7)
leu
lys
phe
tryp
tyr
iso
threo
