amino acids (b1- SMS) Flashcards
what is the only difference between different amino acids?
the -R group
everything else is the same
structure of an amino acid
have α-COOH, α-NH2, H, & -R group
α means attached to central carbon
what are the 5 basis that amino acids are classified on?
1.Structural classification: based on chemical nature of side chain (aliphatic, aromatic, sulfur-containing)
- Presence of polar/nonpolar groups in side chain
- Nutritional Basis: essential (must be obtained from diet) vs. non-essential amino acids (can be synthesized in the body)
- Metabolic Fate: glucogenic (converted into glucose), ketogenic (converted to ketone bodies), or glucogenic + ketogenic
- Standard/ Non-Standard: standard= 20 amino acids directly used for protein synthesis, non-standard= not needed for protein formation
straight chain vs. branched chain amino acids (which amino acids are in each category)
both fall under nonpolar aliphatic amino acids category - there are 5 total aliphatic amino acids
straight chain: glycine, alanine
branched-chain: leucine, isoleucine, valine
aliphatic vs aromatic meaning (for own knowledge)
aliphatic: open-chain (linear or branched)- lack rings or special functional groups
- only have C & H in side chains
aromatic: closed ring structures
structure of glycine & alanine
glycine: simplest amino acid with just H at its -R side chain
alanine: has a methyl (-CH3) group at its side chain
what are the 10 essential amino acids? what is the acronym to remember them?
PVT TIMHALL
P → phenylalanine
V → valine
T → threonine
T → tryptophan
I → isoleucine
M → methionine
H → histidine
A → arginine
L → leucine
L → lysine
what are the sources of essential amino acids & what is their importance?
sources: animal products like egg, milk, fish, beef
importance: required for normal health growth + maintaining normal weight
what are the sulfur containing amino acids?
- cysteine
- methionine
what are the aromatic amino acids?
aromatic = contain benzene-like rings, hydrophobic
- phenylalanine
- tyrosine
- tryptophan
what are the hydroxyl (-OH) containing amino acids?
- serine
- threonine
- tyrosine (also aromatic)
what are acidic and basic amino acids? and what are their examples?
acidic amino acids: have negatively charged side chain at physiological pH
- aspartic acid
- glutamic acid
basic amino acids: have a positively charged side chain at physiological pH
- lysine
- arginine
- histidine
what are nonpolar and polar amino acids? and what are their examples?
nonpolar (hydrophobic): have side chains that do not interact well with water
- glycine
- alanine
- valine
- leucine
- isoleucine
- phenylalanine
- methionine
- proline
- tryptophan
uncharged polar (hydrophilic): have side chains that interact well with water
- serine
- threonine
- tyrosine
- cysteine
- asparagine
- glutamine
what are glucogenic and ketogenic amino acids? both glucogenic and ketogenic? what are the examples of each?
glucogenic: can be converted into glucose via glucogenesis
- a lot
- alanine
- arginine
- aspartic acid (aspartate)
- glutamate
- and so on
ketogenic: can be converted into ketone bodies
- leucine
- lysine
both glucogenic & ketogenic
- tryptophan
- tyrosine
- isoleucine
- phenylalanine
newly added amino acid selenocysteine (notes say MCQ)
considered the 21st amino acid
like its brother cysteine but contains selenium in the place of sulfur
- present in enzyme deiodenase and peroxides
non-standard amino acids + examples
non-standard: do not take part in protein synthesis
examples: GABA (neurotransmitter), β-alanine, homocysteine, ornithine
imino acid + example
imino acid: molecule containing both an imine (C=N) and COOH group
example: proline
