Biochemistry Flashcards
(148 cards)
1
Q
A molecule with a net charge of zero with a positive and negative charge rendering it isoelectric
A
Zwitterion
2
Q
Linear polymers of amino acids
A
Proteins
3
Q
Functions of protein
A
Regulate METABOLISM facilitate CONTRACTION in muscle Provide structural FRAMEWORK SHUTTLE molecules in blood stream component of IMMUNE SYSTEM
4
Q
The set of all the proteins expressed by an individual at a particular time
A
proteome
5
Q
Major goal is to identify proteins and their postranslational modification which correlates with disease, physiologic phenomena and aging
A
Proteomics
6
Q
Which part of its structur dictates function of amino acid
A
R group
7
Q
Nonpolar vs polar
A
Nonpolar is hydrophobic
Polar hydrophilic
8
Q
Amino acid that has the smallest side chain
Used in first step of heme synthesis
A
Glycine
9
Q
Major neurotransmitter in the spinal cord
A
Glycine
10
Q
Carries ammonia and carbons of pyruvate from skeletal muscle to liver
A
Alanine
Together with glycine constitutes major fraction of ammino acid in blood
11
Q
3 ammino acids that accumulate in maple syrup disease
A
Valine leucine isoleucine
12
Q
Phenylalanine
A
Precursor of tyrosine
Differ in only in side ring
13
Q
Accumulates in phenylketonuria
A
Phenylalanine
14
Q
Largest side chain
A
Tryptophan
15
Q
Tryptophan prescursor of
A
Tryp mo siya no (toni)?
Tryptophan = melatonin, serotonin, niacin
16
Q
Precursor of homocysteine
A
MetHionine
17
Q
Actually an imino acid Pasaway Contributes to fibrous structure of collagen Causes kinks No charge
A
Free si Proline na pasaway
Proline
18
Q
Tyrosine is the precursor of
A
L dopa > dopamine >norepinephrine >epinephrine
Thyroxine
Melanin
19
Q
Glutamine is deamminated to ammonia by
A
Glutaminase
20
Q
Major carrier of nitrogen to liver from peripheral tissues
A
Glutamine
21
Q
Site of n linked glycolsylation of proteins
A
Asparagine
22
Q
Ammino acid with sulfhydryl group
A
Cysteine
- participates in biosynthesis of co enzyme a
Cysteine + cysteine = cystine through a covalent disulfide bond
23
Q
Precursor of gaba and glutathione
A
Glutamate
24
Q
Enzyme that turns glutamate to gaba
A
Glutamate decarboxylase
25
Strongest base
Arginine
26
Weak base
Histidine
27
Precursor of histamine
Histidine
28
Used in diagnosis of FOLIC ACID DEFICIENCY thru FIGLU EXCREATION TEST
Histidine
29
Arginine is the precursors of
Creatinine , urea , nitric oxide
30
The 21st amino acid
Selenocysteine
Selenium atom replaces sulfur if cysteine
31
Lathyrus seeds
Nuerolathyrism
Progressive and irreversible spastic paralysis of lower extremities
Homoartinine and beta-N-oxalyldiaminopropionic acid
32
Cycad seeds
Neurotoxic
Implicated in disease such as ALS, Parkinson dementia complex in natives of Guam
Beta-Methylaminoalanine
33
Except for _____ all amino acids are chiral
Glycine
34
All ammino acids in proteins are in
L-configuration
D-configuration: bacterial cell walls and antibiotics
35
Essential ammino acids
PVT TIM HALL always ARGues never TYRs
Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
36
Primary structure :_______________
Secondary structure : ______________
Tertiary structure: ________________
Quarternary structure: _____________
1- sequencing (peptide bonds attach alpha amino group to alpha carbonyl group of another)
2. Folding (folding of short ,30-30 residue, contiguous segments of polypeptide into geometrically ordered units --- hydrogen bond)
3. 3D shape (globular vs fibrous)
4. If more than 1 polypeptide chain
37
Most common secondary structure
| And examples
Alpha helix
Keratin 100%
Hemoglobin 80%
38
Non repetitive secondary structure
Loops and coils
39
Supersecondary structures with no actual function
Motifs
40
First protein sequenced
Insulin
41
Specialized group of proteins required for proper folding
Prevents aggregation
Rescue proteins trapped in misfolded deadend
Chaperones
42
Resluts in unfolding and disorganization of proteins secondary and tertiary structures
Denaturation
43
PrPsc
Prion
44
Factors causing shift to the right
| p50 is increased
Circumstances that needs more oxygen in tissues
```
Increase in (5)
CO2
Acidity thus decrease in ph
Temp
2,3 BPG
Exercise
```
Shift to left lower p50
45
Release of oxygen from hgb is enhanced when it is acidic (lowered ph and increase in carbon dioxide)
Bohr effect
46
Effect of changes in oxyhemoglobin on the CO2 content of pCO2
Haldane effect
47
Hb gower 1:_____;conception
HbF :_______;_______
Hgb A: bone marrow; _________
Hgb A2: ________;shortly after birth onwards
Yolk sac, conception
Liver, first few months to after birth
Marrow, 8months onwards
Marrow, shortly after birth
48
Chains
hbf :________
Hbg A:_________
Hbg A2:________
Alpha 2 gamma 2
Alpha 2 beta
Alpha 2 delata 2
49
Major hgb found in fetus
Fetal hemoglobin
50
HbAIC goal for non pregnant adults
<7%
51
Car, cherry pink
Unconscious
Dx?
Treatment?
Carboxyhemoglobin
| Give 100% oxygen
52
Anxiety headache and dyspnea
"Chocolate cyanosis" with O2 saturation of 85%
Dx? Treatment?
Methemoglobinemia
Mild: oral methylene blue or ascorbic acid (reducing agents)
Acute massive: iv. Methylene blue
53
Ankyrin mutation as the most common
Inherited defect in rbc membrane
Anemia
Splenomegaly
Jaundice
Diagnostic test? Dx?
Treatment?
Osmotic fragility test
Hereditary Spherocytosis
Splenectomy for symptomatic patients
54
Point mutation in both genes for the beta chain that results in valine rather than glutamate
It causes painful crises due to occlusion of the misshapen RBCs however it is protective against malaria
Sickle cell disease
55
In hemoglobin C disease which amino acids are substituted?
Lysine is substituted for glutamate
56
Inadequate synthesis of alpha chains that leads to anemia and accumulation of Hb Bart (gamma 4) and Hb H (Beta 4)
Symptoms appear at birth
Alpha thalassemia
57
Inadequate synthesis of beta chains accumulation of Hb Barts and alpha chain percipitation
Symptoms seen 6months after birth
Beta thalassemia
58
Most abundant protein in the body?
| Most common form?
Collagen
| Type 1 collagen
59
What vitamin is needed in the hydroxylation of collagen?
Vitamin C
60
Collagen is rich in ______ and ________
| ______ facilitates kinking
Glycine and proline
| Proline
61
```
Collagen type I: _________
Collagen type II: _________
Collagen type III:_________
Collagen type IV:________
Collagen type VII:________
```
bONE, tendONE, dentin, fascia, cOrNEa,late wound repair
carTWOlage, vitreous bidy, nucleus pulposus
ReTHREEculin, skin, blood vessels, uterus, fetal tissue, granulation tissue
Four=floor ; basement membrane or basal lamina
VII : stratified squamous epithelium
62
Most common type of Ehlers-Danlos syndrome
Hypermobility - defect is in type III
There is hypermobile joints, skin abn, OA and severe pain
63
Collagen defect in classical Ehlers-Danlos syndrome
Classical -type I and V
Hypermobility - type III (most common)
vascular - type III (most serious)
64
Mutation in collagen genes result to brittle bones
Most common collagen defect?
Osteogenesis Imperfecta
Collagen type 1
Blue sclerae
Hearing loss
Multiple fx
Dental imperfections
65
Genetic disorder affecting structure of collagen type IV: manifestations include hematuria, sensorineural hearing loss, ocular lesions
Alport syndrome "alFOURt"
66
Skin breaks and blisters as a result of minor trauma
Epidermolysis bullosa
| Type VII defect
67
A pirate came to you for poor wound healing. What is your impression?
Vitamin C deficiency
| Scurvy
68
Patient presents with kinky hair (non familial) and growth retardation. What could be included in your impression if this is a nutrient deficiency?
Menkes disease due to copper deficiency
Copper is required by lysyl oxidase
69
Elastin is rich in
Proline and lysine
Precursor tropoelastin deposited into irregular fibrilln scaffold crosslinked by DESMOSINE
70
```
Mutation in fibrillin gene
Presents as tall per and thinner than family members
Arachnodactyly
Dolichostenimelia
Ectopic lentis
```
Autosomal dominant connective tissue disorder - marfan syndrome
71
Most common cardiovascular defect in Marfan syndrome
Aortic dilatation in 79-80% and dissection
72
Alpha 1 antitrypsin deficiency results in
PAN EMPHYSEMA
73
Protein catalysts that increase the velocity of chemical reaction and are not consumed by the reaction they catalyze
They are highly specific and highly efficient
Can be inhibited or regulated
Enymes
74
___________ are physically distinct versions of given enzyme, each of which catalyzes the same reaction
Isozymes
75
Recyclable shuttles that transports substrates from point of gen to point of utilization
Coenzyme
76
This describes how reaction velocity varies with substrate concentration
Assumes that:
s>e
ek
Low P
What equation? What curve?
Michael-Meneten equation
| Hyperbolic curve
77
Km is ______of Vmax
1/2 of VMax
Increase in substrate will increase in velocity until Vmax is reached
Even if substrate continues to rise Vmax will not change
78
Increase in Km will _______affinity
⬆️ km ⬇️affinity
| ⬇️ km ⬆️ affinity
79
Factors that affect rate of reaction (increase or decrease in reaction)
Concentration of substrate
Temprature
pH
80
For a reaction to be spontaneous and favorable the change in energy shoul be
Negative
81
Enthalpy :_________
| Entropy: __________
Heat
| Randomness
82
How is atp produced?
Substrate level phosphorylation
| Oxidative phosphorylation
83
Two requirements for oxidative phosphorylation
Oxygen
| Mitochondria
84
NAD is derived from?
| FAD is derived from?
Nicotinamide Adenine Dinucleotide- Niacin Vitamin B 3
| Flavin Adenine Dinucleotide- riboflavin vitamin B2
85
In electron transport chain, which is the final electron acceptor?
Oxygen
86
In electron transport chain which enzyme is used to produce atp from adp after oxidative phosphorylation?
Atp synthase in complex V
87
How many atps are yeild in one electron transport chain?
Nadh- 2.5
| Fadh-1.5
88
Which complex in the etc is succinate converted to fumarate?
Complex II
89
Hypothesis re etc to produce ATP from ADP+Pi
Mitchell hypothesis
90
Complex inhibitors
Barbiturates
Amytal
Rotenone
Piercidin A
Complex I
91
Complex II inhibitors
*Malonate
Carboxin
TTFA
92
Complex III inhibitors
Antimycin A
| *Dimercaprol
93
Complex IV
CaSHCy
Carbon monoxide
Sodium azide
Hydrogen sulfide
Cyanide
94
If the mitochondria has a defect, which gene is it from? Mother or father
Mother for mitochondria
95
Uncoupling protein important in babies
Thermogenin (brown fat)
96
Synthetic uncouplers
2,4 dinitrophenol, aspirin
97
Only atp synthase inhibitor
Oligomycin
98
Inhibits oxidative phosphorylation by inhibiting adp and atp transporter
Atractyloside
99
Name 3 ROS
Superoxide
Hydrogen peroxide
Hydroxyl radical
100
Defenses against ROS accumulation
Catalase
Peroxidase
Superoxide desmutase
101
Neither catabolic or anabolic. This process is amphibolic
Cirtic acid cycle
102
What is the first substrate in krebs?
Acetyl co-a
103
Second messenger of glucagon and epi (B,a2) ?Protein kinase?
cAMP -protein kinase A
104
Second messenger of insulin and insulin growth factor ? Protein kinase
Tyrosine kinase
| Tyrosine kinase/JAK -STAT
105
Second messenger of nitric oxide and ANP? Protein kinase?
cGMP
| Protein kinase G
106
Second messenger of epinephrine (a1) and protein kinase?
IP3 /DAG protein kinase C
107
Activates cAMP?
Adenylate cyclase
108
Functions of carbohydrates
Major energy source
Storage of energy
Component of cell membrane
Structural components of plants and bacteria
109
Glucose is reduced to ___________
| Glucose is oxidized to ____________
Sorbitol
| Glucoronic acid
110
What are examples of monosaccharides?
Hexoses
Glucose (aldehyde) - sorbitol - glucoronic acid
Fructose (ketone)
Galactose (aldehyde)
Mannose
Pentoses
Ribose
Ribulose
Xylulose
111
Examples of dissachrides
Sucrose (glucose +fructose)
Maltose (glucose+glucose)
Lactose (glucose + galactose)
112
When a hydroxyl group is removed in C2 of ribose, this yeilds what?
Deoxyribose
113
Storage polysaccharides in animals?
Glycogen
114
Chief constituent of plant cell walls?
Cellulose
115
Most important dietary carbohydrate in cereals and potatoes?
Starch
116
Polysaccharide of fructose that is soluble in water and is used to determine GFR?
Inulin
117
Where is glucose absorbed?
Jejunum and duodenum
118
Glucose transporters and their functions
Needed for transport thru cell membrane because glucose is polar
GLUT 1 : BRAIN, colon, placenta, rbcs, kidneys
GLUT 2 : LIVER, PANCREAS, small intestines and kidneys
GLUT 3: BRAIN, kidneys, placenta
GLUT 4: MUSCLE AND ADIPOSE TISSUE (insulin stimulated glucose uptake)
GLUT 5: LUMEN OF small intestine (absorption of FRUCTOSE)
119
Sodium dependent active uptake of glucose against a concentration gradient?
SGLT 1 in small intestines and kidneys
120
Breakdown of glucose
GLYCOLYSIS
121
What activates glucose?
Insulin
Fed state= increase glucose= insulin release= glycolysis
122
Glycolysis
What for?
Where does it occur?
Substrate?
End products?
Rate limiting step?
What for?
Major pathway of glucose metabolism to provide energy
Where does it occur? Cytosol
Substrate? Glucose
End products? 2 molecules of either pyruvate or lactate
Rate limiting step? Phosphorylation of fructose-6-phosphate to fructose-1,6-biphosphate
ENZYME IS PHOSPHOFRUCTOKINASE-1
123
Irreversible and important steps in glycolysis
Step 1: glucose to glucose-6-phosphate thru hexokinase or glucokinase
Step 3: fructose 6 phosphate to fructose 1,6 bisphosphate thru phospho-fructokinase -1
Step 10: Phosphoenolpyruvate to pyruvate thru pyruvate kinase
124
Hexokinase vs glucokinase
```
Hexokinase present in most tissues
-Inhibited by glucose 6-p
-Low Km thus high affinity
-Low VMax
Meet cell need now
```
```
Glucokinase
- liver and the pancreas
- inhibited by fructose -6-p
- high Km low affinity
- high Vmax
For storage
```
125
Product of PFK1? PFK2?
| Activator? Inhibitor?
Product : Fructose 1,6 biphos : fructose 2,6 biphos
Activator: fructose 2,6 BP : well fed state
Inhibitor: citrate and ATP : fasting state
126
Well fed state vs fasting state
Well fed state increase in insulin decrease in glucagon
| Fasting state decrease insulin increase glucagon
127
What are the two steps in glycolysis that produces ATP via substrate level phosphorylation?
1,3 Biphosphoglycerate to 3-phosphoglycerate
ENZYME: PHOSPHOGLYCERATE KINASE
phosphoenolpyruvate to pyruvate
ENZYME IS PYRUVATE KINASE
128
ATP yeild of aerobic GLYCOLYSIS?
Consumed : -2
Substrate level yeild: 4
NADH : 3 (Glycerophosphate) 5(malate aspartate)
NET YEILD: 5 or 7
129
Anaerobic glycolysis will yeild how many ATPs?
Consumed :-2
Substrate level :4
= 2
130
End product of anaerobic glycolyis?
| End product of aerobic glycolysis?
Lactate by lactate dehydrogenase
Pyruvate by
131
Fate of pyruvate
Lactate -> Anaerobic glycolysis
Acetyl coa --> krebs cycle
Oxaloacetate -> gluconeogensis
Ethanol -> fermentation
132
Coenzymes of pyruvate dehydrogenase
All 5 MUST BE PRESENT
```
Thiamine pyrophosphate (B1)
FAD (B2)
NAD (B3)
CoA (pantothenic acid) B5
Lipoic acid
```
133
Most common enzyme defect in glycolysis
Pyruvate kinase deficiency which presents as hemolytic anemia
134
Most common cause of congenital lactic acidosis
Pyruvate dehydrogenase deficiency
| Treat with ketogenic diet
135
Disease caused by a mutation that decrease the activity of glucokinase
MATURITY ONSET DIABETES OF THE YOUNG TYPE 2
136
What vitamin is deficient in chronic alcoholism?
Vitamin B 1 or thiamine
| Alcohol inhibits absorption of B1
137
Final common pathway for aerobic oxidation of carbs, protein and lipids
Citric acid cycle
138
TCA
```
what for?
Where does it occur?
Products?
Substrate?
Rate limiting step?
```
TCA
what for? Major pahway for formation of ATP
Where does it occur? MITOCHONDRIAL MATRIX IN MOST except for succinate dehydrogenase that occurs in the inner mitochondrial membrane
Substrate? Acetyl-Coa
Product? 2 CO2; 1GTP; 3NADH; 1FADH
Rate limiting step? ISOCITRATE TO ALPHA KETOGLUTARATE
ENZYME: isocitrate dehdrogenase
139
Steps in the TCA CYCLE?
CINDY IS KIND SO SHE FORGIVES MORE OFTEN
citrate > isocitrate > alpha KETOGLUTARATE > succinyl COA > succinate>fumarate>malate>oxaloacetate
140
ATP YIELD FOR TCA
```
NADH (2.5x3) = 7.5 ATP
FADH (1.5x1) =1.5 ATP
GTP = 1 ATP
_________________________
10 ATPs
```
141
How many ATPs in Complete oxidation of glucose?
30 anaerobic
| 32 aerobic
142
Pathways that occur in both mitochondria and cytosol?
Heme synthesis
Gluconeogenesis
Urea cycle
143
Gluconeogensis
What for?
Where does it occur?
Product?
Rate limiting step?
Gluconeogensis
What for? To synthesize glucose from non carb source to Prevent hypoglycemia
Where does it occur? Mitochondria and cytosol
Product? GLUCOSE
Rate limiting step?
FRUCTOSE 1,6 BISPHOSPHATE TO FRUCTOSE 6-phosphate
144
Carboxylase needs what vitamin to function?
BIOTIN
145
Lactate formed in skeletal muscle is transported to the liver to be converted back to glucose
CORI CYCLE
146
Enzyme responsible for converting ethanol to acetaldehyde?
Alcohol dehydrogenase
147
Glycogenesis
```
What for?
Where does it occur?
Substrate?
Product?
Rate limiting?
```
Glycogenesis
What for? Synthesis of glycogen
Where does it occur? Liver, muscle and cytosol
Substrate? Alpha D glucose
Product? Glycogen
Rate limiting? Elongation of glycogen chains
Enzyme: glycogen synthase
148
What structure is needed to start glycogenesis? It serves as a primer for glycogen synthesis.
Glycogenin
