Amino Acids and Proteins Flashcards
what are the 4 components of an amino acid
- carboxylic acid group
- variable R group
- hydrogen
- amino group
RNA virus
genetic material stored as RNA (not DNA)
genome can be used in host cell replication machinery and translated into proteins; or their RNA serves as a DNA-like template for protein translation
the only AA that is not chiral
glycine
no optical activity under plane-polarized light
4 types of AA
- hydrophobic amino acids - nonpolar side chains (alkyl groups, aromatic groups)
- hydrophilic (neutral) - polar side chains (hydroxyl (-OH) and sulfhydryl (-SH))
- hydrophilic (acidic) - amino acids that have side chains that contain carboxylic acid (COOH)
- hydrophilic (basic) - amino acids that have amine (-NH2)
see chart
pKa refers to
the point when two species will be in equal concentration
isoelectric point (pI)
the point between the two pKa values
zwitterion
an amino acid that has a net zero charge
- NH3+
- COO-
reverse transcription
generating cDNA from an RNA template (used by viruses to transcribe their RNA genomes into DNA, then integrate into the host DNA genome)
peptide bond
rigid; but can rotate, allowing proteins to fold into different shapes
the NH2 attacks the carbon of the carboxylic group. the -OH group leaves, along with one of the hydrogens from the NH2 group, forming water
rotation around a double bond
restricted due to planar geometry
4 levels of protein structure
primary (alphabet)
secondary (words)
tertiary (sentences)
quaternary
epigenetics
DNA methylation
histone modification
differentiation in type of DNA in different parts of the body
proteins stabilized by
hydrogen bonds between amino acids
primary structure
covalent bonds (amide/peptide bond)
secondary structure
hydrogen bonds
tertiary structure
ionic bonds, disulfide bonds, hydrophobic interactions, hydrogen bonding
quaternary structure
(same as tertiary)
ionic bonds, disulfide bonds, hydrophobic interactions, hydrogen bonds
C- and N-terminal*
n/a
hydrolysis of protein requires…
proteolytic enzymes (protease), strong acids
a method of cleaving peptide bonds
acid hydrolysis with heat
proline*
the side chain is linked to the amino group
amino group
-NH2
alpha helix breakers
proline and glycine
thiol group protein
cysteine
forms disulfide bridges with other cysteine
(“the cysteine chapel is filled with disulfide bridges”)
