Midterms Lec Flashcards
came from the Greek word
proteios which means ‘first place’
proteins
Most abundant organic
molecule in the human body comprising more than 50% of
the cell’s dry mass
protein
Composed of many amino
acids bounded together via the
peptide linkage thus providing
a diverse range of functions
protein
function of protein for support,
contraction, and movement
structural
the
contractile protein of the
muscles (myocytes
actin myosin
component protein
of microtubules
tubulin
function of protein that bind and carry
substances from one place to
another
transport
the carrier of O2 in the
muscles and blood
respectively
myoglobin, hemoglobin
functions of protein that enhance the rate of
biochemical reactions
catalyst
speed up the breakdown of
starch
amylase
more
commonly known as
antibodies produced by
immune cells (lymphocytes)
immunoglobulin
are released into the
bloodstream and regulate the
physiologic activities of their
target cells
hormones
produced by β cells
of the pancreas. It lowers the
level of glucose in the blood.
insulin
deficiency in
insulin leads to this disease
diabetes
function of protein that can be used in metabolic
reactions that yield energy
energy source
major protein in
milk
casein
protein in egg
white
egg albumin
Variation in amino acid is caused by (3)
order of amino acid
chain length
folding the chain in distinct ways
about this much protein
should be consumed in the diet
14 percent
source of protein include:
meat
fish
eggs
peas
beans
nuts
breaks down proteins in
order to be absorbed into the
bloodstream to be assimilated by the
body
enzymes
used to test for protein
copper sulfate solution
sodium hydroxide
Can be also called Biuret
solution
copper sulfate
sodium hydroxide
overall threedimensional
shape of protein
native fonrimation
Four hierarchical levels of protein
primary
secondary
tertiary
quaternary
The amino acid sequence of
the protein. This is the sole
determinant of its overall
shape
primary structure
rule that states the amino acid sequence is the sole determinant of its overall shape
Anfinsen’s rule
The first amino acid residue
is written to the left as the _-terminal
N
Meanwhile, the __terminal
is always the last
and rightmost amino acid.
C
The local folding of protein
segment into helical or
sheet-like structure
secondary structure
formed by the
coiling of the polypeptide
chain into a right-handed
spiral
alpha-helix
formed
when two adjacent chains of
polypeptides forms H-bonds
in an almost fully extended
form that can be likened to
the pleats of an accordion
beta-pleated sheet
The compact threedimensional
structure or
native conformation of
protein
tertiary
tertiary structure is stabilized by:
H-bonds
Salt bridges
hydrophobic interactions
disulfide bridges
In general, proteins are
either ____or ____in
shape.
fibrous
globular
those that
exist as fibers or sheets. They
are made up of one type of
secondary structure and
function for structural
support
fibrous proteins
Examples include: collagen,
keratin, and silk fibroin
fibrous protein
combinations of different
secondary structures that
compactly folded into
spherical shapes
globular protein
Examples include: enzmes,
myoglobin, and hemoglobin
globulular protein
Involves the interaction of the
subunits of an oligomeric
protein
quaternary
proteins like hemoglobin
quaternary structrure
functional group formed
when a peptide bond is made
amide
– 3-10 amino acids
combining
oligopeptide
- > 10 amino acids
polypeptide
each monomeric unit in the
polypeptide
residue
localized conformation of the chain
secondary protein structure
peptide bond has this
character due to resonance
Pi bond
bonds
formed in the β-pleated sheet
dipole dipole interactions
Stores energy, example of a
favorable conformation
dipole dipole interactions
spiral shaped with 3.6
residues for turn
alpha helix
➢ R groups are pointing out
alpha helix
Factors that influence tertiary
structure
hydrophobic residues
hydrophilic residues
through mild
oxidation, two cysteine can react to
form this bond
disulfide bond
Covalent linkage between two
sulfur atoms
disulfide bond
sulfur analog of a hydroxyl
group
thiol
amino acid
residue of Glutamic acid is changed
to Valine
sickle cell disease
most abundant protein in
the human bod
collagen
Cementing component of
various connective tissues
like bones, tendons,
ligaments, and skin
collagen
Made up of three-left handed
helices that are twisted
together to form a righthanded
super helix (likened to
a rope made of three cords)
collagen
Tough, yet flexible
collagen
Structure is a repeating
sequence of what
Gly-Pro-X
X in collagen can be
4-hydroxyproline
lysine residue
essential
for this hydroxylation and is
therefore critical in maintaining the
structural integrity of collagen
ascorbic acid
severe deficiency in vitamin
C leads to this, which is
characterized by swelling and
inflammation of gums, impaired
healing of wounds, loosening of
teeth, pain in joints, and progressive
weakening of the body
scurvy
major fibrous protein
in hair and nails, and a minor
constituent of the skin
alpha keratin
Component of the cells
cytoskeleton that maintains
their shape
alpha keratin
Made up of two alpha-helices
that are twisted together to
form a left-handed super helix
alpha keratin
extensively
stabilize the structure of
keratin
disulfide bond
in fat, it is the major
protein in the extra cellular matrix
collagen
Most abundant protein in
vertebrate
collagen
collagen has two types
fibrillar type
non-fibrilar
Five most common type of collagens
are:
Type I- V
type of collagen that is abundant in skin,
tendon, vasculature, organs,
bone (main component of the
organic part of the bone)
type I
type of collagen that is cartilage (main
collagenous component of
cartilage)
type II
reticulate (main
component of reticular fibers,
commonly found alongside
type I)
type II
forms basal lamina,
the epithelium-secreted layer
of the basement membrane
type of collagen
type IV collagen
, plays an essential role in the health of our hair and cell surfaces. It contributes to the strength and thickness of hair strands, promoting healthy hair growth.
type of collagen
type V
Has two identical chains (a1)
and additional chain that
differs slightly in its chemical
composition (a2)
collagen
have 25 different alpha
chains encoded by different genes
vertebrates
is found at almost
every third residue in collagen
glycine
makes up about 17
percent of collagen
proline
can be
derived from proline
hydroxyproline
depending on the
type of collagen, varying
numbers of hydroxylysines
are ______(mostly
having disaccharides
attached)
glycosylated
Basic composition is
essentially the same, but
myoglobin is made up of a
____ unit while hemoglobin
has ____subunits
single
four
nonprotein
component of the subunit
prothestic group
group in hemoglobin which
consist of a tetrapyrrole ring called
porphyrin with a coordinated Fe2+
atom
heme
the released
myoglobin is filtered by the kidneys
but is toxic to the renal tubular
epithelium and so may cause acute
kidney injury
rhabdomyolysis
myoglobin and hemoglobin
bind to this
oxygen
how many amino acids in myoglobin
153
how many amino acids in hemoglobin
146aa (b)
141aa (a)
who has a higher affinity for oxygen?
myo or hemo?
myo
which is for storage? for transport?
myo or hemo
myo - storage
hemo - transport
which has distinct structural change
myo or hemo
myo
constraints between subunits
oppose the structural changes
resulting from ligand binding
T state
constraints are released in the
subunits, thus enhancing
ligand-binding affinity
R state
genetic disease
where RBCs can take the shape of a
sickle
sickle cell anemia
More easily destroyed,
causing anemia
sickle cell anemia
– made up of
two α-globin and two β-globin
hemoglobin A
A/B-globin cells end up
misshapen
B
can carry oxygen, but changes
shape when deoxygenated that can
clump with other sickle hemoglobin
HbS
decreases Hb
affinity for O2
acidosis
free hemoglobin is
bounded by this, recycling it
haptoglobin
low levels of this is a sign of
intravascular hemolysis
haptoglobin
peptide hormone that is
produced by the beta cells of the
pancreas
insulin
beta cells of pancreas
islets of langerhans
dimetric protein made up of Achain
and B-chain which
contains 21 and 30 amino acid
residues respectively
insulin
has two alpha helical
regions at A1-A8 and A12-A19
which are anti parallel
a chain
has a central alpha
helical structure from amino
acid B9-B19 which are flanked
by the disulfide bond on either
sides and two beta sheets at
amino acid B7-B10 and B-20
and B-23
b chain
deficiency in
insulin production or resistance to
insulin results to this, which is a
metabolic disorder that is
characterized by hyperglycemia
diabetes mellitus
high blood
sugar resulting to serious
health complications like
kidney failure, cardiovascular
disease, stroke, nerve
damage, and eye damage
hyperglycemia
Symptoms include frequent
urination, increased thirst,
impaired wound healing, and
increased appetite
hyperglycemia
- How are proteins formed:
replication
transcription
translation
large molecules made up
of chains of amino acids
proteins
all essential
amino acids are present
complete proteins
food with complete proteins
beef
poultry
fish
eggs
soy
include nuts,
seed, beans
incomplete proteins
determines the function
of the protein
structure
all information
required to specify the structure of a
protein is encoded in this
primary structure
local folding
of protein segment:
secondary structure
coiling into right
handed spiral, 10 turns 5.4
nanometers
a helix
adjacent
polypeptide chains form H
bonds
beta pleated sheet
3D structure that are
slender, fibers or sheets made up of
1 type of secondary structure
fibrous structure
3D structure that is
spherical, compact and forms
hydrophilic and hydrophobic regions
globular
Made up of different
secondary structures
globular
oxidation reaction in
which carbon-hydrogen bond
oxidizes to carbon-hydroxyl
hydroxylation
