Proteins Flashcards
essential macronutrients
proteins
Naturally-occurring
proteins
unbranched polymer in which the
monomer units
amino acids
Account for about _____ of a cell’s overall mass.
15%, most abundant
Elemental composition of protein
Carbon, hydrogen, nitrogen (N),
oxygen (O), and sulfur (S)
Average nitrogen content is ____ by mass
15.4%
act as catalyst in enzyme; iron (Fe), phosphorus (P), and other metals in
certain specialized proteins
metalloproteins
metalloproteins
iron (Fe), phosphorus (P)
THE BUILDING
BLOCKS
OF PROTEINS (monomers)
amino acids
Amino acids in which the amino group
and the carboxyl group are attached to the
alpha-carbon
atom.
Representation of Side chain
R
Vary in size, shape, charge, acidity,
functional groups present, hydrogen-bonding ability,
and chemical reactivity. (identity)
Side chain (R)
____naturally occurring amino acids are known.
700
How many Standard Amino Acids
20
1 amino group + 1 carboxylic acid
group + 1 nonpolar group
Nonpolar amino acids
Not attracted to water molecules
• Found in the interior of proteins, where there is no
polarity
Hydrophobic
how many non-polar acids
9
what kind of amino acid is Hydrophilic
Polar amino acids
1 amino group + 1 carboxylic acid group + 1
neutral polar group
Polar neutral
do not carry charges
neutral
The side chains of these amino acids exhibit
intermolecular forces of attraction
Polar neutral
makes the amino acid
capable of interacting with polar solvents such as water
intermolecular forces of attraction
In physiological conditions, the side chains of polar amino
acids are ________
uncharged
normal physiological pH
2-7
1 amino group + 1 carboxylic acid group + 1 acidic
group
Polar acidic
Contains two acidic groups: carboxylic group, acidic side chain
Polar acidic
In physiological conditions, the side chains of these amino acids
are _______charged due to the loss of the _______ atom.
negatively; acidic
hydrogen
two polar acidic amino acid
aspartic acid (aspartate) and glutamic acid (glutamate)
1 amino group + 1 carboxylic acid group + 1 basic
group
Polar basic
In physiological conditions, the side chains of these amino acids
are positively charged due to the nitrogen atom gaining an acidic
hydrogen
Polar basic
gaining an acidic
hydrogen
protonated
In physiological conditions, the side chains of these amino acids
are positively charged due to the ______ gaining an acidic
hydrogen
nitrogen atom
exempted in 3 letter symbols
Isoleucine (Ile), tryptophan (Trp),
asparagine (Asn), and glutamine (Gln)
