Globular & Fibrous Proteins Flashcards
Globular proteins has peptide chains folded into _____ or _____ _____
Spherical or globular shapes
Hydrophobic side chains are in the ____
Interior
Polar side chains are on the
Exterior
5 example of globular proteins
Hemoglobin, immunoglobulin, myoglobin, insulin, transferrin
Two proteins, myoglobin and hemoglobin are ___ proteins
Heme
Proteins that maintain a supply of oxygen essential for oxidative phosphorylation
Heme proteins
Heme Proteins maintain a supply of oxygen essential for?
oxidative phosphorylation
A cyclic tetrapyrrole linked by methylene bridges
Heme
Resides at the center of the planar ring
Ferrous ion
The oxidation of ferrous to ____ ion destroys biological activity of these proteins thus giving the blood a ___ color.
Ferric , red
A MONOMERIC protein
Myoglobin
Myo in myoglobin means
Muscles
Tetrameric protein
Hemoglobin
Myoglobin is found in ____ that serves as reservoir in times of oxygen deprivation
Red muscles
Myoglobin is rich in?
a-helices (75%)
The a-helices contains two special histidine residue.
His E7 and His F8
His E7 (distal histidine) and His F8 (proximal
histidine). These two residues lie close to the
____ and assist in ____
heme iron, oxygen binding.
A tetrameric protein found in ___
which transport oxygen to the ____ and
returns carbon dioxide and protons to the
lungs
erythrocytes, tissues
A tetrameric protein found in erythrocytes
which transport ____ to the tissues and
returns _____ to the
lungs
oxygen, carbon dioxide and protons
Hemoglobin is a multi-subunit protein represented by
,
πΌ2π½2
the ____ of hemoglobin closely resemble
the structure of myoglobin.
π½ subunits
present in
hemoglobin provide additional mechanisms of
control.
Allosteric sites
(for regulation; molecules
can bind here
Allosteric sites
an oxygen molecule
binds more readily to hemoglobin if other
oxygen molecules are already bound
Cooperative binding
Hemoglobin can bind up to
4 oxygen
molecules, one per heme.
The subunits of hemoglobin Γ§an exist in two states
Relaxed and Taut State
more open; oxygen has higher affinity for
this state;
Relaxed
tighter structure; oxygen has lower affinity for
this state;
Taut
default state when oxygen concentration is high
Relaxed
default state when oxygen is absent
Taut
The ability of hemoglobin to
reversibly bind oxygen is affected
by the
ππ2
Binding of π2, in hemoglobin
drives the release of .
πΆπ2
Hemoglobin (Hb) binds _____ with increasing affinity.
Oxygen
Binding of π2, in hemoglobin
drives the release of πΆπ2. This
is depended upon the
cooperative interactions
between the hemes of the
hemoglobin tetramer.
Effect of
______
Stabilizes the Taut state and promotes
release of π2.
2,3-bisphosphoglycerate
Effect of
2,3-bisphosphoglycerate
Stabilizes the ___ and promotes
release of ___.
Taut state, π2
The role of 2,3-biphosphoglycerate is especially
significant for ____ where
pressure of π2 is low.
high altitudes
Imagine your
climbing to the top of the mountain, once
your body feels ____ __ ____ due
to the increase of altitude, the ____
tries to release the stored oxygen, to
supply it to the body.
depletion of oxygen, 2,3-BPG
This is similar to
____ who wore ____
behind them when diving in a deep
ocean.
scuba divers, oxygen tanks
Have traditionally been defines as a family of genetic
disorders caused by production of a structurally
abnormal hemoglobin molecule.
HEMOGLOBINOPATHIES
Common Hemoglobinopathies:
- Sickle Cell Anemia (Hemoglobin S disease)
- Hemoglobin C disease
Glu amino acid is mutated to a Val
Sickle Cell Anemia (Hemoglobin S disease)
Glu amino acid is mutated to Lysine
Hemoglobin C disease
has an elongated shape
Fibrous protein
Fibrous protein tends to have ____, ___, ____, structures
simple, regular, and
linear
tend to aggregate together to form
macromolecular structures
Fibrous protein
Examples of fibrous protein
Keratin and collagen
Is a component of bone and connective tissue
Collagen
Collagen is the the most
abundant protein in ____.
vertebrates
Collagens structure is organized in
______ ____ of great strength
water-insoluble fibers
A _____ consists of three polypeptide chains
wrapped around each other in a ropelike twist or triple
helix.
collagen fiber
These three strands or polypeptide chains are held together by ___
bonds
hydrogen
These hydrogen bonds involves
hydroxyproline and hydroxylysine
residues
Collagen is both intramolecularly and intermolecularly
linked by ____.
covalent bonds
___ increases with
age.
Cross-linking
amino acids of
collagen structure are arranged in a repetitious tripeptide sequence,
Gly β X β Y, in which X can be any amino acids but is
frequently a ____ and Y is frequently a ___ or ____
Proline, hydroxyproline
or hydroxylysine.
Gly β X β Y β Gly β X β Y β Gly β X β Y β
Supply x and Y
Gly β Pro β Hyp β Gly β Pro β Hyl β Gly β Pro β Hyp
Normal collagens are ___ ___ molecules, having
half-lives as long as several years.
highly stable
Collagen has an _____, ___-___ structure that places many of its amino acid
side chains on the surface of the triple-helical molecule.
elongated,
triple-helical
The structure of collagen as triple helical: Resulted to bonding of the exposed ____ of
neighboring collagen monomers, thus the aggregations
into a very long fibers.
R-groups
In short, amount of
collagen will decrease
as we grow. Thus
wrinkles and fine lines
appear in our face, a
proof that skin collagen is ____
depleting.
COLLAGEN DISEASES: ___
Collagenopathies
This disorder is a
heterogeneous group of generalized connective tissue
disorders that result from inheritable defects in the
metabolism of fibrillary collagen molecules.
Ehlers-Danlos syndrome (EDS)
This disease is a heterogeneous
group of inherited disorders distinguished by bones that
easily bend and fracture.
Osteogenesis imperfecta (OI)
Retarded wound healing and a
rotated and twisted spine leading to a β____β
appearance are common features of this disease.
humped-back
The ____ of hemoglobin provides additional properties which are absent from monomeric myoglobin
Quaternary structure
What are the two general types of proteins?
Globular and Fibrous Proteins
Among the 5 globular proteins what are the 2 heme proteins
Myoglobin and Hemoglobin
What are the two substances that confer ability to these heme proteins to transport and store oxygen.
Heme and Ferrous Ion
Heme and Ferrous Ion are two substances that confer ability to the heme proteins in what process?
transport and store oxygen.
Heme is a ___ ___ linked by methylene bridges
Cyclic tetrapyrrole
Heme is a cyclic tetrapyrrole linked by ____
Methylene bridges
Ferrous ion resides at the ____ of the planar ring
Center
Ferrous ion resides at the center of the ____
planar ring
The _____ of ferrous to ferric ion destroys the biological activity of heme proteins.
Oxidation
The oxidation of ___ to ___ destroys the biological activity of heme proteins.
ferrous, ferric ion
The oxidation of ferrous to ferric ion destroys the _____ of ____.
biological activity, heme proteins
Myoglobin is found in red muscles which serves as _____ in times of oxygen deprivation
Reservoir
Myoglobin is found in red muscles which serves as reservoir in times of ___
Oxygen deprivation
Myoglobin can only bind to ___ ____ ____.
One oxygen molecule
Cooperative binding is exhibited in what protein?
Globular: Hemoglobin
Hemoglobin exhibits what?
Cooperative binding
What are the three allosteric effects?
Heme - heme interactions
Bohr Effect
Effects of 2,3-biphosphoglycerate
A globular protein that stores oxygen
Myoglobin
A globular protein that supplies oxygen
Hemoglobin
What allosteric effect us the ability of hemoglobin to reversibly bind oxygen which is affected by pO2
Heme-Heme Interactions
In short, when oxygen, if combined to one of the heme, the other hemes _____ to accept oxygen.
Activate
Hemoglobin has an increasing affinity for
O2
The allosteric effect: binding of O2 in hemoglobin drives the release of CO2
Bohr effect
The bohr effect is depended upon the _____ between the hemes of the hemoglobin tetramer
Cooperative interactions
In short, when oxygen binds with the heme, ____ will be detached
Carbon dioxide
In this case, carbon dioxide leaves in our body thru ____
Exhaling
High altitudes have a ___ __ of O2
Low pressure
Tends to have simple, regular, and linear structures
Fibrous proteins
What is the shape of fibrous protein?
Elongated shape
A collagen fiber consists of three polypeptide chains wrapped around each other in a _____ or triple helix
Ropelike twist
A collagen fiber consists of ___ ___ ___ wrapped around each other in a ropelike twist or triple helix
three polypeptide chains
A collagen fiber consists of three polypeptide chains wrapped around each other in a ropelike twist or ___ __
triple helix
The three strands are held together by hydrogen bonds that involves?
Hydroxyproline hydroxylysine
Collagen is both ____ and ____ linked by covalent bonds
Intermolecularly intramolecularly
What increases with age?
Cross-linking
Collagen belongs to ____ structure protein
Secondary
What belongs to secondary structure protein?
Collagen
Collagen belongs to secondary ___ ___
Structure protein
The amino acid sequence of collagen are arranged in a repetitious ____ ____
Tripeptide sequence
The amino acid sequence of collagen are arranged in a repetitious tripeptide sequence: ___-___-___
Gly-X-Y
The X in Gly-X-Y can be any ______
Amino acid
The X in Gly-X-Y can be any amino acids but is frequently a ___
Proline
The Y in Gly-X-Y is frequently a __ or ___
Hydroxyproline hydroxylysine
Even if normal collagens are highly stable its connective
tissue is ____ and is constantly being ___
often in response to growth or injury of the tissue
Dynamic, remodeled
Even if normal collagens are highly stable its connective
tissue is dynamic and is constantly being remodeled
often in response to ___ or ___ __ __ ____
growth or injury of the tissue
Normal collagens are highly stable molecules having ____ as long as several years
Half-lives
The structure of collagen as triple helical: Resulted to bonding of the exposed R-groups of
neighboring __ __, thus the aggregations
into a very long fibers.
Collagen monomers
The structure of collagen as triple helical: Resulted to bonding of the exposed R-groups of
neighboring collagen monomers, thus the ____
into a very long fibers.
aggregations
The structure of collagen as triple helical: Resulted to bonding of the exposed R-groups of
neighboring collagen monomers, thus the aggregations
into a ___ __ __.
very long fibers.
The structure of collagen as triple helical: Resulted to bonding of the exposed ___ of
neighboring collagen monomers, thus the aggregations
into a very long fibers.
R-groups
In short, amount of
collagen will ____
as we grow.
decrease
In short, amount of
collagen will decrease
as we grow. Thus,
__ and ___
appear in our face, a
proof that skin collagen is depleting
wrinkles, fine lines
EDS results from deficiency of ___-____ enzymes or from mutations in the amino acid sequence
Collagen-processing
EDS results from deficiency if collagen-processing enzymes or from ___ in the amino acid sequence
mutations
EDS results from two things what are these?
deficiency of collagen-processing enzymes or from mutations in the amino acid sequence
Osteogenesis imperfecta is also known as
Brittle bone syndrome
OI is a heterogeneous group of ___ disorders
Inherited
OI is distinguished by bones that easily __ or ___
Bend or fracture
What are the two common features of the OI disease
Retarded wound healing and a rotated and twisted spine that leads to the humped back appearance
What is the lethal form of OI
Type II
The lethal form of OI is when the fractures appear in ___, as revealed by this radiograph of a stillborn fetus
Utero
The lethal form of OI is when the fractures appear in utero, as revealed by this radiograph of a __ __
stillborn fetus
Collagen has an elongated, triple-helical structure that places many of its ___ ___ ___ ___ on the surface of the triple helical molecule
Amino acid side chains
Collagen has an elongated, triple-helical structure that places many of its amino acid side chains on the ___ of the ___ ___ ___.
Surface, triple helical molecule
Cross-linking increases by?
Age
In short, amount of
collagen will decrease
as we grow. Thus,
wrinkles and fine lines
appear in our face, a
proof that ____ ___ is depleting
Skin collagen
