Exam 2 Flashcards
Most abundant biomolecule in the body
Proteins
Proteins _______ every process in the cell
MEDIATE every process
Building blocks of proteins
amino acids
There are ___ total amino acids.
_________ was the first discovered in 1806.
_________ was the last discovered in 1908
20 total
Asparagine (1806)
Threonine (1938)
All amino acids are anchored to an __ carbon
(alpha) carbon
All amino acids have chiral center except…
Glycine
Almost all carboxyl and amino groups are bound in _______ bond.
Peptide
L - Amino Acid (acronym + direction)
CORN clockwise
D - Amino Acid (acronym + direction)
CORN counter clockwise
Amino acid that contains a hydrocarbon is __________.
Aliphatic
_______ (nonpolar) replaces glutamine (polar) in hemoglobin.
causes it to fold incorrectly
Valine (replaces glutamine)
Valine replacing glutamine causes hemoglobin to fold incorrectly. This is know as ______ _____ ______
Sickle Cell Anemia
Genetic deficiency of enzymes required to metabolize branched chain amino acids.
Maple Syrup Urine Disease
Methionine and Proline are ________ _______ R groups
Nonpolar Aliphatic
Leucine, Isoleucine and Valine are nonpolar aliphatic R groups with….
Branched Chain Amino Acids
Gluten = _______ + ________
Gliadin + Glutenin
_______ is the alcohol-soluble portion in wheat.
Gliadin
Genetic disorder that lacks enzyme necessary to metabolize phenylalanine
Phenylketonuria (PKU)
Phenylketonuria:
Causes…
__/_______ babies born with
Treatment:
Phenylketonuria:
Causes BRAIN DAMAGE.
1/10,000 babies born with.
Treatment: Avoid PHENYLALANINE
Phenylalanine is found in… (2)
Nutrasweet
Anything with protein
Most common disorder
Cystic Fibrosis
Cystic Fibrosis:
_______ disorder affecting __/______ humans.
Missing __ __________ in protein that regulates transport of chloride ions across cell membranes.
Cystic Fibrosis:
GENETIC disorder affecting 1/2,000 humans.
Missing 1 PHENYLALANINE in protein that regulates transport of chloride ions across cell membranes.
Cystine =
Disulfide Bridge
_______ and _______ are 2 of many proteins stabalized by disulfide bridges.
Albumin
Insulin
Precursor for nitric oxide.
Arginine
Precursor for histmaine
Histidine
Amyloids:
- Normal cellular proteins that ________ and _______ _________.
- _______ is key for holding it together through __________ and __________ interactions.
Amyloids:
- Normal cellular proteins that UNRAVEL and STICK TOGETHER.
- LYSINE is key for holding it together through HYDROPHOBIC and ELECTROSTATIC interactions.
Tangles: (2)
Microtubules become phosphorylated and behave unnaturally.
Accumulation can cause them to ruptore/
Alzheimer’s Disease Proteins: (2)
Amyloids
Tangles
New, potential treatment for alzheimers:
CLR01 binds to lysine and arginine
____ of all glutamate is used by the cells lining the _____ _______. So, very little enters the __________
90% of all glutamate is used by cells lining the SMALL INTESTINE. So, very little enters the BLOODSTREAM
The brain makes its own glutamate, which is turned into _____ (_____ _______)
GABA (quiet neurons)
MSG
Monosodium Glutamate
The major amino acid in plants
Glutamate
Precursor to dopamine
Tyrosine
9 essential amino acids
(PVT MT HILL) Phenylalanine Valine Tryptophan Methionine Threonine Histidine Isoleucine Lysine Leucine
Nonessential Glucogenic only (10)
(AAAA C GGG PS) Alanine, Arginine, Asparagine, Aspartate, Cysteine, Glutamate, Glutamine, Glycine, Proline, Serine
Essential Glucogenic only (4)
Histidine
Methionine
Threonine
Valine
Nonessential Glucogenic and Ketogenic
Tyrosine
Essential Glucogenic and Ketogenic (3)
Isoleucine
Phenylalanine
Tryptophan
Essential Ketogenic only (2)
(“Lindsey Lohan = Fat Only”)
Leucine
Lysine
2 uncommon amino acids found in collagen
Hydroxyproline
Hydroxylysine
Methyllysine
Part of myosin
Desmosine
Part of elastin
Carboxyglutamate (2)
2 carboxylic acids total
Found in proteins that stimulate clotting and bone synthesis
Selenocysteine
Special amino acid derivative that uses selenium instead of sulfur
When pH is high, amino acids can…
Donate H+
When it comes to donating and accepting protons, the proton donor is always the ________ group and the proton acceptor is always the ________ group
Proton Donor - AMINO group
Proton Acceptor - Carboxyl group
When pH is _____, amino acids can accept H+
Low
Compounds that can act as an acid and base
Amphoteric
If pH is below pK…
If pH is above pK…
below pK = H is still attached
above pK = H is lost
pK1 is the removal of H from the ______ group.
pK2 is the removal of H from the ______ group.
pKr is the removal of H from the ______ group.
pK1 = removal from CARBOXYL group pK2 = removal from AMINO group pKr = removal from R group
If pH is below both pK1 and pK2… (2)
Both pK1 and pK2 are PROTONATED (fully protonated)
Both H still attached
________: Amino group and carboxyl group cancel each other out - no charge.
Zwitterion
When pH is above pK1 and pKr, but below pK2, net charge = ___
net charge = -1
H on pK1 and pKr is lost… H still attached to amino group
______ ________: pH is above pK1, pKr and pK2.
Net Charge = ____
Fully Deprotonated
Net Charge = -2 (carboxyl and R group become negatively charged and amino group becomes neutral)
The point where an AA or protein is neutral (zwitterion)
Isoelectric Point
Chains of amino acids
Peptides
Peptides:
Contains peptide bond formed by ________.
Many amino acids is called a _________.
Dehydration - removal of 1 H2O for each peptide bond
Polypeptide
Proteins:
Chains of amino acids…
Contains ________ bonds
Proteins:
chains of amino acids WITH MOLECULAR WEIGHT >10,000
contains PEPTIDE bonds
3D structure of a protein is determined by its…
Amino Acid Sequence
The most important stabilizing force for protein structures are…
Noncovalent Interactions
Protein structures are (static/dynamic)
DYNAMIC - NOT static
________: Spatial arrangement of atoms in a protein.
Conformation
-
Native
- most stable
- has lowest Gibbs free energy
_______: Proteins ability to maintain the native conformation.
Held together by…
Stability
Held together by DISULFIDE bonds and WEAK (NONCOVALENT) INTERACTIONS.
Simple Rules of Protein Structure:
Hydrophobic amino acids are…
_______ and __________ interactions are maximized within the protein
Hydrophobic amino acids are BURIED in the middle of the structure, away from water.
H BONDS and ELECTROSTATIC interactions are maximized within the protein
Levels of Protein Structure:
Primary: (2)
Sequence of amino acids
Includes covalent bonding (peptide bonds)
Peptide bonds are formed via…
Condensation/Dehydration reactions
________ = 2 AA
Polypeptide = ___ - ___ AA
>_____ AA is a protien
DIPEPTIDE = 2 AA Polypeptide = 10-100 AA Protein = >100 AA
Synthesis of all macronutrients are _________ reactions
Dehydration
Polypeptide backbone is rich in ________ and ______ groups which are great at _________ ________.
Polypeptide backbone is rich in CARBONYLS and AMINO groups which are great at HYDROGEN BONDING
Most polypeptides are ___-_____ AA residues in length
50-2,000 AA
_______ - Largest known protein.
_______ AA residues
Titin
27,000 AA residues
Protein Secondary Structure Arrangements: (3)
All held together by…
Alpha Helix
Beta Sheets
Beta Turns
held together by H-BONDS
The overall 3D structure of the protein
Tertiary Structure
Tertiary structure is held together by: (2)
Covalent Bonds - Disulfide Bridges
Noncovalent Bonds - Electrostatic, H-bonding, hydrophobic
_______: 2 or more separate polypeptides in a protein
Quaternary Structure:
Subunits
Quaternary Structure: Subunits fold together to form a protein