MOD2 L3 Flashcards
1
Q
FIBROUS PROTEINS
3
A
COLLAGEN
ELASTIN
KERATIN
2
Q
GLOBULAR PROTEINS
2
A
MYOGLOBIN
HEMOGLOBIN
3
Q
- Triple helix
- Has 3.3 residues per turn and a rise per residue nearly twice that of an α-helix
- Every 3rd amino acid residue is a glycine residue
- Gly-Pro-X or Gly-Hyp-X
A
COLLAGEN
4
Q
COLLAGEN
Every 3rd amino acid residue is a
A
GLYCINE RESIDUE
5
Q
sequence of collagen structure
A
Gly-Pro-X
x could be any rare amino acid (could be hydroxyproline or hydroxylysine)
6
Q
COLLAGEN STRUCTURE
what do we need in order for us to achieve the hydroxylated form of proline & lysine
A
ASCORBIC ACID IN THE FORM OF ASCORBATE
7
Q
saan nakukuha ang ascorbate
A
in our diet
Vit C supplement
8
Q
in the biosynthesis of collagen, we need to have the chain of ____
A
PRE-PROCOLLAGEN ON RIBOSOMES
9
Q
synonym of protein synthesis
A
TRANSLATION
10
Q
BIOSYNTHESIS OF COLLAGEN
the ____ directs the pre-procollagen to the RER
A
SIGNAL PROTEIN
11
Q
BIOSYNTHESIS OF COLLAGEN
removing a certain portion
removal of registration peptides
A
CLEAVAGE
12
Q
BIOSNTHESIS OF COLLAGEN
cleavage of signal protein forms ____
A
PROCOLLAGEN
13
Q
process of biosynthesis of collagen
in order
A
- chain of pre-procollagen, directed to RER by signal proteins
- formation of cleavage of signal protein = forms collagen
- hydroxylation of lysine & proline
14
Q
enzymes in biosynthesis of collagen
A
PEPTIDYL LYSINE HYDROXYLASE
PEPTIDYL PROLINE HYDROXYLASE
15
Q
addition of OH- group
A
HYDROXYLATION
16
Q
BIOSYNTHESIS OF COLLAGEN
attachment of sugar to some hydroxylysine residues
A
GLYCOSYLATION
17
Q
BIOSYNTHESIS OF COLLAGEN (GLYCOSYLATION)
Addition of ____ and ____ to some
hydroxylysine residues.
A
GALACTOSE
GLUCOSE
18
Q
BIOSYNTHESIS OF COLLAGEN
enzymes required for glycosylation
A
GALACTOSYL TRANSFERASE
GLYCOSYL TRANSFERASE
19
Q
involves transfer of groups
A
TRANSFERASE
20
Q
BIOSYNTHESIS OF COLLAGEN
how many α-chains of procollagen are needed to have self association
A
3
21
Q
BIOSYNTHESIS OF COLLAGEN
what is needed to have stability of procollagen
A
DISULFIDE BONDS
22
Q
BIOSYNTHESIS OF COLLAGEN
formation of disulfide bonds is called
A
REGISTRATION PEPTIDES
23
Q
BIOSYNTHESIS OF COLLAGEN
involves the formation of disulfide bonds between parts of the polypeptide chains
A
ASSEMBLY OF THREE α-CHAINS TO FORM PROCOLLAGEN
24
Q
BIOSYNTHESIS OF COLLAGEN
formation of disulfide bonds between parts of the polypeptide chains known as ____ which occur at both ends of the pre-procollagen.
A
REGISTRATION PEPTIDES
25
# BIOSYNTHESIS OF COLLAGEN
registration peptides are **found** at the
ends of pre-procollagen
26
# BIOSYNTHESIS OF COLLAGEN
The **assembly process** of 3 α-chains occurs in the
GOLGI APPARATUS
27
# BIOSYNTHESIS OF COLLAGEN
**Secretion** of procollagen molecules by ____ into the extra cellular space
EXOCYTOSIS
28
# BIOSYNTHEIS OF COLLAGEN
* Occurs in the **extra cellular space**, and is **catalyzed by procollagen peptidases**.
* The **resulting molecule** is called **tropocollagen**.
CLEAVAGE OF REGISTRATION PEPTIDES
29
# BIOSYNTHESIS OF COLLAGEN
the **resulting molecule** in the cleavage of registration peptides
TROPOCOLLAGEN
30
# BIOSYNTHESIS OF COLLAGEN
cleavage of registration peptides occurs in the
EXTRACELLULAR SPACE
31
# BIOSYNTHESIS OF COLLAGEN
cleavage of registration peptides is catalyzed by
PROCOLLAGEN PEPTIDASES
32
# BIOSYNTHESIS OF COLLAGEN
**Self-assembly** or **polymerization of tropocollagen** molecules form
COLLAGEN FIBRILS
33
# BIOSYNTHESIS OF COLLAGEN
____ between adjacent tropocollagen molecules **stabilizes the fibrils**.
CROSS-LINKAGE
34
# BIOSYNTHESIS OF COLLAGEN
Self-assembly or polymerization of tropocollagen molecules involves the ____ which **has a net oxidative effect** and the **formation of covalent cross-links**.
REMOVAL OF AN AMINO GROUP
35
# BIOSYNTHESIS OF COLLAGEN
Self-assembly or polymerization of tropocollagen molecules is **catalyzed** by
LYSINE OXIDASE / CATALASE
36
* like a **glue**
* holds our **joint** together
COLLAGEN
37
* **Inheritable** defects in collagen molecule;
* Characterized by **stretchy skin** and **loose joints**;
* Due to **defect in genes** that encode α- collagen-1, procollagen N-peptidase, or lysyl hydroxylase.
EHLERS-DANLOS SYNDROME
38
a person suffering from this disease has a **flexible body structure**
EHLERS-DANLOS SYNDROME
39
deficiency in α- collagen-1, procollagen N-peptidase, or lysyl hydroxylase
EHLERS-DANLOS SYNDROME
40
* **severe** form of ehlers-danlos syndrome
* prone in falling; possibility to have bone breakages
VASCULAR TYPE
41
* **Brittle bone** syndrome
* Bones **easily** **bend** and **fracture**
* stunted growth
* irregular bone structures
* permanent disability
OSTEOGENESIS IMPERFECTA
42
osteogenesis imperfecta is also known as
brittle bone syndrome
43
* Characterized by **kinky hair** and **growth retardation**
* Due to **dietary deficiency of copper required by lysyl oxidase**, which catalyzes a key step in the formation of the covalent cross-links that strengthen collagen fibers.
* a **genetic disorder** caused by a **mutation usually primarily in the Y Chromosome (boys)** it affects the copper levels and metabolism in the body causing seizures, brain damage, weakened bones and muscles, organ shutdown and failure to thrive.
MENKE'S SYNDROME
KINKY HAIR SYNDROME
44
Menke's syndrome is otherwise known as
KINKY HAIR SYNDROME
45
common **affected** by the menke's syndrome / kinky hair syndrome
MALE / BOYS
46
* Best known **defect in collagen biosynthesis**;
* **Deficiency of Vit. C** (required by prolyl and lysyl hydroxylases);
* Bleeding gums, swelling joints, poor wound healing, and ultimately death.
SCURVY
47
required by proline & lysyl hydroxylases
VIT C
ASCORBIC ACID
48
* Connective tissue protein with **rubber-like** properties
* Found in **lungs**, **walls of large blood vessels**, and **elastic ligaments**
* Can be **stretched** to **several time their normal length**, but **recoil** to their **original shape** when **relaxed**.
ELASTIN
49
* responsible for **lung's elastic property**
* its ability to **inflate** & **deflate**
ELASTIN
50
* Composed primarily of **small non polar** amino acid residues (e.g. **G, A, V**).
* Also **rich in proline and lysine**, but contains **little hydroxyproline and hydroxylysine**.
* Interchain cross-links form **desmosine residues**.
ELASTIN
51
interchain cross-links of **elastin** form
DESMOSINE RESIDUES
52
An extensively interconnected, **rubbery network** that can **stretch** and **bend** in **any direction** when **stressed**, giving connective tissue elasticity.
DESMOSINE CROSS-LINK
53
one of the **leading case of non communicable diseases** accdng to the DOH
EPHYSEMA
54
* does not have **repair mechanism**
* cannot deactivate **neutrophil elastases**
EMPHYSEMA
55
**reactive oxygen species (ROS)** are also known as
FREE RADICALS
56
stimulates **pro-inflammatory mediators** such as IL-8, LTB, TNF
NICOTINE
57
**Inhibit neutrophil elastase** (protease that degrades elastin of alveolar walls)
α-1 antitrypsin
58
**Deficiency** of α-1 antitrypsin leads to **destruction of the alveolar walls** of the lungs resulting to
EMPHYSEMA
59
treatment for emphysema
administration of α-1 AT
60
* the lungs **natural defense** against the irritants
* **attach** themselves to the **foreign material** in the sac and **consumes it** as well as bacteria in the lungs
ELASTASE
61
Once the lungs has been cleaned,
____ **deactivates** elastase.
ANTITRYPSIN
62
**Without the antitrypsin** enzyme, the ____ **continues to consume** anything in its path, **including healthy lung tissue**.
ELASTASE
63
* Proteins that forms **tough fibers**;
* Found in the **hair**, **nails**, and **outer epidermal layers** of mammals;
* Constituents of **intermediate filaments of cytoskeleton** in certain cells.
α-KERATIN
64
why hair and nails are **insoluble** in water
non polar R groups are found outside which makes it insoluble in water
65
* Group of **specialized protein** that contains **heme**.
* Maintain a **supply of oxygen** essential for oxidative metabolism
– MYOGLOBIN
– HEMOGLOBIN
GLOBULAR HEMEPROTEINS
66
* **Fe+2-** protoporphyrin IX
* A **cyclic tetrapyrrole**
* protein that are produced by amino acids
* A planar network of conjugate double bonds **absorbs visible light** and colors heme **deep RED**.
HEME
67
amino acids that are **not directly involved** in protein synthesis
NON PROTEINOGENIC
68
* A **monomeric protein** (153 amino acid residues) of the red muscles
* Used in some tissues, notably muscle,
– as a **storage reserve** of O2
and
– for **intracellular transport** of O2
MYOGLOBIN (Mb)
69
**predominant secondary structure** that is visible in the tructure of myoglobin
α-helix
70
myo means
muscles
71
* **78% α helical** (the other **22%** in β **turns** and **short loops**, **no β sheet at all**)
* 8 α - helices and connections between helices are referred to as "**AB**", "**CD**", etc.
* **Polar** amino acid residues are **found at the surface**
* **Non polar** amino acid residues (L, V, F, & M) are **found at the interior** **except His E7 and HisF8**
MYOGLOBIN
72
The **heme** of **myoglobin** lies in **crevices** of
HELICES E & F
73
# SUBUNIT COMPOSITION
**Fetal** hemoglobin (HbF)
α2γ2
74
**major hemoglobin** in adults
HEMOGLOBIN A (HgA)
75
# SUBUNIT COMPOSITION
Hemoglobin A
α2β2
76
# SUBUNIT COMPOSITION
**sickle cell** hemoglobin (HbS)
α2S2
77
# SUBUNIT COMPOSITION
**minor adult** hemoglobin (HbA2)
α2δ2
78
have **almost identical** secondary and tertiary structures
Myoglobin and the β polypeptide of hemoglobin
79
composed of two identical
dimers, (αβ)1 and (αβ)2, dimers 1 and 2
respectively
Hgb tetramer
80
**Dimers** are **held together** by
HYDROPHOBIC INTERACTIONS
81
also occur between the members of the dimer
IONIC & H-BONDING
82
* **Deoxy form** of Hgb
* Two αβ dimers interact through a network of ionic bonds and hydrogen bonds
T FORM OR TAUT (TENSE) FORM
83
**Low oxygen-affinity** form of hemoglobin
T FORM OR TAUT (TENSE) FORM
84
* **Binding of oxygen** to Hgb (oxyhemoglobin)
* Some ionic bonds and H-bonds between the αβ dimers are **ruptured** thus, the polypeptide chains have **more freedom of movement**
R FORM OR RELAXED FORM
85
**High oxygen-affinity** form of hemoglobin
R FORM OR RELAXED FORM
86
Hemoglobin **binding sites** per molecule
4 O₂
87
____ cooperate in binding oxygen
SUBUNITS
88
The **oxygen dissociation curve** for **Hemoglobin** is ____ in shape
SIGMOIDAL
89
Can bind only **one molecule of oxygen** (one heme group only)
MYOGLOBIN
90
The **oxygen dissociation
curve** for **Myoglobin** is a ____ shape
HYPERBOLIC
91
**reversibly binds** a single molecule of oxygen
MYOGLOBIN
92
* It means that the **binding** of an **oxygen molecule** at **one heme group** **increases** the **oxygen affinity** of the **remaining heme group** in the **same Hgb** molecule
* This is referred to as **heme-heme
interaction**
COOPERATIVE BINDING OF OXYGEN
93
**cooperative binding of oxygen** is also referred to as
HEME-HEME INTERACTION
94
**cooperative interactions** are also called
ALLOSTERIC INTERACTIONS
95
allos
OTHER
96
STEREOS
SPACE
97
a ligand that **influences** other ligand to bind at a specific site
ALLOSTERIC EFFECTOR / MODULATOR
98
occur when binding of one ligand at a specific site is influenced by binding of another ligand
ALLOSTERIC INTERACTIONS
99
**second site** in allosteric interactions
ALLOSTERIC SITE
100
the **interacting sites** all bind the **same ligand** (e.g., binding of O2 at one site on Hb influences the binding affinity for O2 of another site)
HOMOTROPIC INTERACTION/EFFECT
101
the **interacting sites** bind **different ligands**
HETEROTROPIC INTERACTION/EFFECT
102
* Positive effect
* the effector **increases** the **binding affinity** for the **same kind of ligand** at other sites
* O2 in the hemoglobin system increases the O2 binding affinity of other sites
HOMOTROPIC INTERACTION / EFFECT
103
**increases the binding affinity** for the **same kind of ligand** at other sites
HOMOTROPIC EFFECTOR
104
* the effector **decreases** the **binding affinity** for the **primary ligand**
* protons, or CO2, or 2,3-BPG
NEGATIVE HETEROTROPIC EFFECTOR / ALLOSTERIC INHIBITOR
105
effector **increases** the **binding affinity** for the **primary ligand**
POSITIVE HETEROTROPIC EFFECTOR / ALLOSTERIC ACTIVATOR
106
**effect** of **binding of protons** (H+) and CO₂ on O₂ **binding affinity** of **Hb**
HbO₂ + H+ ↔ HbH+ + O₂
BOHR EFFECT
107
**Increase** **protons** or a **lower** pO₂
Deoxyhemoglobin
108
**Decrease** protons or an **increase** pO₂
Oxyhemoglobin
109
has darker color
| oxyhemog or deoxyhemog
OXYHEMOGLOBIN
110
**CO₂** is a ____ of O₂ binding to Hb
NEGATIVE HETEROTROPIC EFFECTOR / ALLOSTERIC INHIBITOR
111
**CO** binds ____ (but ____) to the Hb iron, forming **carbon monoxyhemoglobin**, HbCO
TIGHTLY, REVERSIBLY
112
CO binding to **one or more** of the **4 heme sites** of Hb shifts to
RELAXED CONFORMATION
113
The **affinity** of Hb for CO is ____ greater than for oxygen
220x
114
% of HbCO are fatal
60%
115
**CO poisoning** is **treated** with ____, which facilitates the **dissociation of CO**.
OXYGEN THERAPY
116
# CO %
mild poisoning
0,08%
117
# CO
moderate posioning
up to 0,32%
118
# CO
severe poisoning
above 1,2%
119
* **Most abundant organic phosphate** in the red blood cells
* **Binds strongly** to the **deoxy form** of **Hb (T state)**, but only **very weakly** to **oxy form (R state)**
* **Favors/stabilizes the T form**, **reducing** the **O2 binding affinity** of Hb (shifts binding curve to the right);
* **Increased concentration** of 2,3-BPG, **reduce affinity of hemoglobin** for O2 which **increases the efficiency of O2 delivery** (**enhances RELEASE**) to tissues
2,3-bisphosphoglycerate (2,3-BPG) or "2,3-diphosphoglycerate" (DPG)
120
Increase concentration of 2,3-BPG is observed in:
*Chronic hypoxia
*High altitudes
*Chronic anemia
121
* The **heme iron** is **ferric than ferrous**
* **Oxidation** of ferrous to ferric is caused by the **side effects of drugs** such as **sulfonamides**, or endogenous substance like **hydrogen peroxide**
* Can **neither bind nor transport oxygen**
METHEMOGLOBIN
122
**HisF8** has been **replaced** by **tyrosine**
HEMOGLOBIN M
123
**V** has **replaced** **Glu6** of the β-subunit
HEMOGLOBIN S
124
**Dark red coloration of urine** following **massive crush injury** because myoglobin is released from damaged muscle fibers
MYOGLOBINURIA
125
**Reduction** in the number of **RBC** or of Hb in the blood, or **impaired production of erythrocytes** (Vit.B12 deficiency)
ANEMIA
126
**Partial** or **total absence** of one or more α (α-thalassemia) or β (β-thalassemia) chains of hemoglobin
THALASSEMIA
127
* **Glucose enters the erythrocytes** and glycosylates the α-group of lysine residues and the amino terminal of Hb
* **Reflects** the **mean blood glucose concentration** thus provides valuable information for **management of Diabetes Mellitus**
GLYCATED HEMOGLOBIN (HbA₁c)
128
to know if the patient is resistant to OHAS, the HbA₁c should be around
5.7-6.4
