Amino Acids Flashcards
The alpha carbon is chiral in all molecules except _____
glycine
All amino acids found in natural proteins are ______amino acids
L-amino acids (with a few exceptions)
A zwitterion amino acid exist in ____state and has no overall _____but have parts of positive and negative charges
solid state; net charge
____ amino acids are used directly in the processes of protein synthesis
Standard
____amino acids are modified after the protein is completed or used in other cellular processes (such as the urea cycle)
Non standard
Single amino acids within a protein often are referred to as amino acid ______
residues
What are essential amino acids
Amino acids acquired through diet
What are the essential amino acids
- Histidine
- Isoleucine
- Leucine
- Lysine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
What are conditionally non essential amino acids
required at some stages of growth or by some people who cannot synthesize them, either because of genetics or a medical condition
What are the conditionally non essential amino acids
- Arginine
- Asparagine
- Glutamine
- Glycine
- Proline
- Serine
- Tyrosine
what are the non essential amino acids
- Alanine
- Aspartate
- Cysteine
- Glutamate
What are the nonpolar, aliphatic amino acids
- Alanine (Ala, A)
- Glycine (Gly, G)
- Isoleucine (Ile, I)
- Leucine (Leu, L)
- Methionine (Met, M)
- Proline (Pro, P)
- Valine (Val, V)
What are non polar, aliphatic amino acids important for
hydrophobic protein interactions.
Gly allows structural flexibility due to its small ____
size
Pro reduces flexiblity because of its ___amino group structure
secondary. Its rigid and distrupts protein folding structures. It connects beta strands
What is considered a copper trafficking protein
methionine
What are the polar, uncharged amino acids
- Cysteine (Cys, C)
- Asparagine (Asn, N)
- Glutamine (Gln, Q)
- Serine (Ser, S)
- Threonine (Thr, T)
What is the polarity due to in the polar, uncharged amino acids
- OH groups (Ser, Thr)
- S atom (Cys)
- amide groups (Asn, Gln)
The -OH sites of serine and threonine are sites for _____ modifications
covalent
Cysteine forms covalent disulfide bonds important for _____folding
protein
Asparagine and Glutamine are important ______donors/carriers
Nitrogen
Hydrogen bonds stabilize the _____ structure
secondary. Found in alpha helices and beta sheets
What are the aromatic amino acids
- Phenylalaline (Phe, F)
- Tyrosine (Tyr, Y)
- Tryptophan (Trp, W)
Aromatic amino acids are relatively ______polar so they can participate in _____interactions.
nonpolar; hydrophobic
A catecholamine is a naturally occurring amine that is ______and functions as neurotransmitter and ____
aromatic; hormones
Tyrosine–>DOPA–>Dopamine–>Norephinephrine–>_____
Epinephrine
What are some positively charged (basic) amino acids
- Arginine (Arg, R)
- Histidine (His, H)
- Lysine (Lys, K)
What are some negatively charged (acidic) amino acids
- Aspartate (Asp, D)
2. Glutamate (Glu, E)
Why are they negatively charged?
Carboxyl group (COO-) side chain
What do the negatively charged acidic amino acids participate in
in the formation of salt bridges and stabilize the tertiary structure
what are the nonstandard amino acids
- 4-hydroxyproline:
- 5-hydroxylysine: both collagen
- N- methyllysine: myosin
- y-carboxyglutamate: Prothrombin
- Desmosine: Elastin
Non standard amino acids are _____after the protein is synthesized
modified
What are collagen specific amino acids
Important in cross linking of fibrils
What is ascorbate a cofactor for
prolyl hyroxylase
What is demosine made of
4 lysine residues; contributes to stretchiness of elastin
