Biochemistry Flashcards
A molecule with a net charge of zero with a positive and negative charge rendering it isoelectric
Zwitterion
Linear polymers of amino acids
Proteins
Functions of protein
Regulate METABOLISM facilitate CONTRACTION in muscle Provide structural FRAMEWORK SHUTTLE molecules in blood stream component of IMMUNE SYSTEM
The set of all the proteins expressed by an individual at a particular time
proteome
Major goal is to identify proteins and their postranslational modification which correlates with disease, physiologic phenomena and aging
Proteomics
Which part of its structur dictates function of amino acid
R group
Nonpolar vs polar
Nonpolar is hydrophobic
Polar hydrophilic
Amino acid that has the smallest side chain
Used in first step of heme synthesis
Glycine
Major neurotransmitter in the spinal cord
Glycine
Carries ammonia and carbons of pyruvate from skeletal muscle to liver
Alanine
Together with glycine constitutes major fraction of ammino acid in blood
3 ammino acids that accumulate in maple syrup disease
Valine leucine isoleucine
Phenylalanine
Precursor of tyrosine
Differ in only in side ring
Accumulates in phenylketonuria
Phenylalanine
Largest side chain
Tryptophan
Tryptophan prescursor of
Tryp mo siya no (toni)?
Tryptophan = melatonin, serotonin, niacin
Precursor of homocysteine
MetHionine
Actually an imino acid Pasaway Contributes to fibrous structure of collagen Causes kinks No charge
Free si Proline na pasaway
Proline
Tyrosine is the precursor of
L dopa > dopamine >norepinephrine >epinephrine
Thyroxine
Melanin
Glutamine is deamminated to ammonia by
Glutaminase
Major carrier of nitrogen to liver from peripheral tissues
Glutamine
Site of n linked glycolsylation of proteins
Asparagine
Ammino acid with sulfhydryl group
Cysteine
- participates in biosynthesis of co enzyme a
Cysteine + cysteine = cystine through a covalent disulfide bond
Precursor of gaba and glutathione
Glutamate
Enzyme that turns glutamate to gaba
Glutamate decarboxylase
Strongest base
Arginine
Weak base
Histidine
Precursor of histamine
Histidine
Used in diagnosis of FOLIC ACID DEFICIENCY thru FIGLU EXCREATION TEST
Histidine
Arginine is the precursors of
Creatinine , urea , nitric oxide
The 21st amino acid
Selenocysteine
Selenium atom replaces sulfur if cysteine
Lathyrus seeds
Nuerolathyrism
Progressive and irreversible spastic paralysis of lower extremities
Homoartinine and beta-N-oxalyldiaminopropionic acid
Cycad seeds
Neurotoxic
Implicated in disease such as ALS, Parkinson dementia complex in natives of Guam
Beta-Methylaminoalanine
Except for _____ all amino acids are chiral
Glycine
All ammino acids in proteins are in
L-configuration
D-configuration: bacterial cell walls and antibiotics
Essential ammino acids
PVT TIM HALL always ARGues never TYRs
Phenylalanine
Valine
Tryptophan
Threonine
Isoleucine
Methionine
Histidine
Arginine
Leucine
Lysine
Primary structure :_______________
Secondary structure : ______________
Tertiary structure: ________________
Quarternary structure: _____________
1- sequencing (peptide bonds attach alpha amino group to alpha carbonyl group of another)
- Folding (folding of short ,30-30 residue, contiguous segments of polypeptide into geometrically ordered units — hydrogen bond)
- 3D shape (globular vs fibrous)
- If more than 1 polypeptide chain
Most common secondary structure
And examples
Alpha helix
Keratin 100%
Hemoglobin 80%
Non repetitive secondary structure
Loops and coils
Supersecondary structures with no actual function
Motifs
First protein sequenced
Insulin
Specialized group of proteins required for proper folding
Prevents aggregation
Rescue proteins trapped in misfolded deadend
Chaperones
Resluts in unfolding and disorganization of proteins secondary and tertiary structures
Denaturation
PrPsc
Prion
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
Release of oxygen from hgb is enhanced when it is acidic (lowered ph and increase in carbon dioxide)
Bohr effect
Effect of changes in oxyhemoglobin on the CO2 content of pCO2
Haldane effect
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
Chains
hbf :________
Hbg A:_________
Hbg A2:________
Alpha 2 gamma 2
Alpha 2 beta
Alpha 2 delata 2
Major hgb found in fetus
Fetal hemoglobin
HbAIC goal for non pregnant adults
<7%
Car, cherry pink
Unconscious
Dx?
Treatment?
Carboxyhemoglobin
Give 100% oxygen
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
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
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
In hemoglobin C disease which amino acids are substituted?
Lysine is substituted for glutamate
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
Inadequate synthesis of beta chains accumulation of Hb Barts and alpha chain percipitation
Symptoms seen 6months after birth
Beta thalassemia
Most abundant protein in the body?
Most common form?
Collagen
Type 1 collagen
What vitamin is needed in the hydroxylation of collagen?
Vitamin C
Collagen is rich in ______ and ________
______ facilitates kinking
Glycine and proline
Proline
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
Most common type of Ehlers-Danlos syndrome
Hypermobility - defect is in type III
There is hypermobile joints, skin abn, OA and severe pain
Collagen defect in classical Ehlers-Danlos syndrome
Classical -type I and V
Hypermobility - type III (most common)
vascular - type III (most serious)
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
Genetic disorder affecting structure of collagen type IV: manifestations include hematuria, sensorineural hearing loss, ocular lesions
Alport syndrome “alFOURt”
Skin breaks and blisters as a result of minor trauma
Epidermolysis bullosa
Type VII defect
A pirate came to you for poor wound healing. What is your impression?
Vitamin C deficiency
Scurvy
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
Elastin is rich in
Proline and lysine
Precursor tropoelastin deposited into irregular fibrilln scaffold crosslinked by DESMOSINE
Mutation in fibrillin gene Presents as tall per and thinner than family members Arachnodactyly Dolichostenimelia Ectopic lentis
Autosomal dominant connective tissue disorder - marfan syndrome
Most common cardiovascular defect in Marfan syndrome
Aortic dilatation in 79-80% and dissection
Alpha 1 antitrypsin deficiency results in
PAN EMPHYSEMA
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
___________ are physically distinct versions of given enzyme, each of which catalyzes the same reaction
Isozymes
Recyclable shuttles that transports substrates from point of gen to point of utilization
Coenzyme
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
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
Increase in Km will _______affinity
⬆️ km ⬇️affinity
⬇️ km ⬆️ affinity
Factors that affect rate of reaction (increase or decrease in reaction)
Concentration of substrate
Temprature
pH
For a reaction to be spontaneous and favorable the change in energy shoul be
Negative
Enthalpy :_________
Entropy: __________
Heat
Randomness
How is atp produced?
Substrate level phosphorylation
Oxidative phosphorylation
Two requirements for oxidative phosphorylation
Oxygen
Mitochondria
NAD is derived from?
FAD is derived from?
Nicotinamide Adenine Dinucleotide- Niacin Vitamin B 3
Flavin Adenine Dinucleotide- riboflavin vitamin B2
In electron transport chain, which is the final electron acceptor?
Oxygen
In electron transport chain which enzyme is used to produce atp from adp after oxidative phosphorylation?
Atp synthase in complex V
How many atps are yeild in one electron transport chain?
Nadh- 2.5
Fadh-1.5
Which complex in the etc is succinate converted to fumarate?
Complex II
Hypothesis re etc to produce ATP from ADP+Pi
Mitchell hypothesis
Complex inhibitors
Barbiturates
Amytal
Rotenone
Piercidin A
Complex I
Complex II inhibitors
*Malonate
Carboxin
TTFA
Complex III inhibitors
Antimycin A
*Dimercaprol
Complex IV
CaSHCy
Carbon monoxide
Sodium azide
Hydrogen sulfide
Cyanide
If the mitochondria has a defect, which gene is it from? Mother or father
Mother for mitochondria
Uncoupling protein important in babies
Thermogenin (brown fat)
Synthetic uncouplers
2,4 dinitrophenol, aspirin
Only atp synthase inhibitor
Oligomycin
Inhibits oxidative phosphorylation by inhibiting adp and atp transporter
Atractyloside
Name 3 ROS
Superoxide
Hydrogen peroxide
Hydroxyl radical
Defenses against ROS accumulation
Catalase
Peroxidase
Superoxide desmutase
Neither catabolic or anabolic. This process is amphibolic
Cirtic acid cycle
What is the first substrate in krebs?
Acetyl co-a
Second messenger of glucagon and epi (B,a2) ?Protein kinase?
cAMP -protein kinase A
Second messenger of insulin and insulin growth factor ? Protein kinase
Tyrosine kinase
Tyrosine kinase/JAK -STAT
Second messenger of nitric oxide and ANP? Protein kinase?
cGMP
Protein kinase G
Second messenger of epinephrine (a1) and protein kinase?
IP3 /DAG protein kinase C
Activates cAMP?
Adenylate cyclase
Functions of carbohydrates
Major energy source
Storage of energy
Component of cell membrane
Structural components of plants and bacteria
Glucose is reduced to ___________
Glucose is oxidized to ____________
Sorbitol
Glucoronic acid
What are examples of monosaccharides?
Hexoses
Glucose (aldehyde) - sorbitol - glucoronic acid
Fructose (ketone)
Galactose (aldehyde)
Mannose
Pentoses
Ribose
Ribulose
Xylulose
Examples of dissachrides
Sucrose (glucose +fructose)
Maltose (glucose+glucose)
Lactose (glucose + galactose)
When a hydroxyl group is removed in C2 of ribose, this yeilds what?
Deoxyribose
Storage polysaccharides in animals?
Glycogen
Chief constituent of plant cell walls?
Cellulose
Most important dietary carbohydrate in cereals and potatoes?
Starch
Polysaccharide of fructose that is soluble in water and is used to determine GFR?
Inulin
Where is glucose absorbed?
Jejunum and duodenum
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)
Sodium dependent active uptake of glucose against a concentration gradient?
SGLT 1 in small intestines and kidneys
Breakdown of glucose
GLYCOLYSIS
What activates glucose?
Insulin
Fed state= increase glucose= insulin release= glycolysis
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
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
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
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
Well fed state vs fasting state
Well fed state increase in insulin decrease in glucagon
Fasting state decrease insulin increase glucagon
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
ATP yeild of aerobic GLYCOLYSIS?
Consumed : -2
Substrate level yeild: 4
NADH : 3 (Glycerophosphate) 5(malate aspartate)
NET YEILD: 5 or 7
Anaerobic glycolysis will yeild how many ATPs?
Consumed :-2
Substrate level :4
= 2
End product of anaerobic glycolyis?
End product of aerobic glycolysis?
Lactate by lactate dehydrogenase
Pyruvate by
Fate of pyruvate
Lactate -> Anaerobic glycolysis
Acetyl coa –> krebs cycle
Oxaloacetate -> gluconeogensis
Ethanol -> fermentation
Coenzymes of pyruvate dehydrogenase
All 5 MUST BE PRESENT
Thiamine pyrophosphate (B1) FAD (B2) NAD (B3) CoA (pantothenic acid) B5 Lipoic acid
Most common enzyme defect in glycolysis
Pyruvate kinase deficiency which presents as hemolytic anemia
Most common cause of congenital lactic acidosis
Pyruvate dehydrogenase deficiency
Treat with ketogenic diet
Disease caused by a mutation that decrease the activity of glucokinase
MATURITY ONSET DIABETES OF THE YOUNG TYPE 2
What vitamin is deficient in chronic alcoholism?
Vitamin B 1 or thiamine
Alcohol inhibits absorption of B1
Final common pathway for aerobic oxidation of carbs, protein and lipids
Citric acid cycle
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
Steps in the TCA CYCLE?
CINDY IS KIND SO SHE FORGIVES MORE OFTEN
citrate > isocitrate > alpha KETOGLUTARATE > succinyl COA > succinate>fumarate>malate>oxaloacetate
ATP YIELD FOR TCA
NADH (2.5x3) = 7.5 ATP FADH (1.5x1) =1.5 ATP GTP = 1 ATP \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ 10 ATPs
How many ATPs in Complete oxidation of glucose?
30 anaerobic
32 aerobic
Pathways that occur in both mitochondria and cytosol?
Heme synthesis
Gluconeogenesis
Urea cycle
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
Carboxylase needs what vitamin to function?
BIOTIN
Lactate formed in skeletal muscle is transported to the liver to be converted back to glucose
CORI CYCLE
Enzyme responsible for converting ethanol to acetaldehyde?
Alcohol dehydrogenase
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
What structure is needed to start glycogenesis? It serves as a primer for glycogen synthesis.
Glycogenin