studystack 1 Flashcards
Enzymes, Carbohydrates, Proteins, Amino acids
Two major metabolic amino acids from muscle protein degradation?
Alanine
Glutamine
Which hormone stimulates adipose stores to mobilize?
Glucagon
Which tissues metabolize glutamine?
GUT
Kidney
Besides protons, what else can decrease the affinity of HbA for O2?
2,3-bisphosphoglycerate (BPG or DPG)
At normal pH, amino groups have what charge?
Positive
Branched chain amino acids.
Valine (V)
Leucine (L)
Isoleucine (I)
The n-side chain is a common site for what?
Glycosylation
Positively charged basic molecules
Arginine (R)
Lysine (K)
Histidine (H)
Bonds that held Cystine.
Disulfide bonds
Amino acid that causes kinks in the peptide chain.
Proline
Primary hemoglobin in adults.
HbA
If the body wants to release oxygen, which form of hemoglobin will it use? If it wants to uptake oxygen?
Taut; Relaxed
Hexokinase and Glucokinase are what kind of molecules?
Isozyme
The only site that can reverse or dephosphorylate glucose-6-phosphate and export glucose?
Liver
Rate limiting enzyme of glycolysis.
Phosphofructokinase 1
PFK-1
Products of aerobic glycolysis.
Pyruvate
Products of anaerobic glycolysis.
Lactate
Site of glycolysis.
Cytosol
2 requirements for aerobic glycolysis.
Oxygen
Mitochondria
ATPs produced when using malate aspartate shuttle.
5 ATP
In hypoxia, what happens to 2,3-BPG in RBC’s?
Increases
Enzyme that adds phosphate from ATP to a molecule’s hydroxyl group.
Kinase
Aerobic NADH reoxidation to NAD+ occurs via what process?
Oxidative phosphorylation
2,3-BPG is produced via?
Glycolysis
Inorganic component (minerals) essential to make the reaction work
Cofactor
Organic component (vitamins) essential to make the reaction work
Coenzyme
Complete enzyme: functional enzyme.
Holoenzyme
Enzyme missing cofactor or coenzyme.
Apoenzyme
Enzyme precursor: Must be converted to active form.
Zymogen
Adds water, CO2 or ammonia to doubble bond or removes them from double bond.
Lyase
When [s] = km, them Vo = ?
1/2 Vmax
When Vo = 1|2 Vmax then [s] = ?
Km
If the concentration of substrate [s] is smaller than Km, what is the reaction dependant on?
Substrate
Competitive inhibition
When the concentration of substrate is bigger than Km, what is the reaction dependant on?
Non competitive inhibition
In Phosphorylation of glycogen phosphorylase, ____ activity
Increases
In Phosphorylation of glycogen synthase, ____ activity
Decreases
Regulatory enzymes in a cascade (rate limiting). Activator or inmhibitor binds to an allosteric site on the enzyme. Feedback inhibition. Tells the enzyme to speed up or slow down. Act like a noncompetitive inhibitor.
Allosteric Enzymes
Two specialized products derived from Tryptophan?
Serotonin, Niacin (NAD, NADP)
GABA is derived from which amino acid?
Glutamine
One specialized product that uses the entire structure of glycine?
Heme
What enzyme combines succinyl-CoA and glycine to start the Heme pathway?
ALA (aminolevulinic acid) synthetase
The rate of the reaction at saturation substrate concentrations for a given amount of enzyme.
Vmax
The substrate concentration that results in 50% Vmax.
Km
Competitive inhibitors ____________ (increase / decrease) the apparent Km.
Increase
An inhibitor that binds to, and takes an enzyme out of commission is called a ____________ inhibitor.
Noncompetitive inhibitor
NAD is synthesized from what vitamin?
Niacin (B3)
FAD is synthesized from what vitamin?
Riboflavin (B2)
TPP is what vitamin?
Thiamine (B1)
What would competitive inhibition affect km or vmax?
Km
In noncompetitive inhibition, what is changed?
Vmax
Alzheimer’s disease has what specific plaque formation?
Beta amyloid
How many CO2 released in TCA?
2
When alpha-keto acids enter the TCA cycle what are the final products?
CO2, H2O, ATP
Enzyme deficient in Maple Syrup Urine Disease.
Branched-chain Alpha-keto acid dehydrogenase
L-glucose and D-glucose are examples of.
Enantiomers
Most predominant carbohydrate enantiomer in humans.
D
Monosaccharides that have the same chemical formula and different structural formula.
Isomers
Monosaccharides that are Epimers at C4.
Glucose and Galactose
Monosaccharides that are Epimers at C2.
Glucose and Mannose
What is the linkage between a pentose sugar and purine/pyrimidine?
beta-glycosidic linkage
Galactose in the lens of children with untreated galactosemia get?
Galactitol formation
What kind of sugar is lactose?
reducing sugar
What should be avoided in diet in children with Aldolase B deficiency?
Fructose
Cellulose composition and linkages.
glucose linked by beta 1-4 glycosidic linkages
Describe Vmax and Km for glucokinase vs. hexokinase?
Glucokinase Vmax and Km is higher. than hexokinase
Which steps in glycolysis are irreversible?
1) hexokinase/glucokinase
2) PFK-1
3) Pyruvate kinase enzyme reactions
Blocks enolase from converting 2 phosphoglycerate into phosphoenol pyruvate in glycolysis.
Fluoride
What is the fate of pyruvate in aerobic conditions?
Converted to acetyl CoA by pyruvate dehydrogenase and enters TCA cycle
What is the fate of pyruvate in anaerobic conditions?
Converted to lactate by lactate dehydrogenase and goes to liver via Cori cycle
Enzyme converts Pyruvate to Lactate.
LDH
What happens to the NADH formed in glucose under aerobic conditions?
Each NADH is used in ETC to produce 3 ATP (in malate-aspartate) 2 ATP (in glycerol-phosphate shuttle).
What happens to the 2,3 BPG level in people from high altitudes?
Increased
To facilitate unloading of oxygen.
What is the second most common form of hemolytic anemia?
Pyruvate kinase deficiency in RBCs
What is the most common form of hemolytic anemia?
G6PD deficiency
What effect when tumor cells use glycolysis as the main source of ATP
Warburg effect
Makes a phosphodiester bond between adjacent nucleotides in DNA.
DNA Ligase
The biochemical function of cAMP is to activate _______________.
Protein kinase A
Has a high Km for glucose and is active after a big meal.
Glucokinase
The enzyme primarily responsible for metabolizing alcohol.
Alcohol dehydrogenase
Stimulates the activity of phosphofructokinase-1 (PFK-1).
Fructose 2,6-bisphosphate
Rate limiting enzyme in cholesterol biosynthesis.
HMGCoA reductase
Catalyzes the first step in glycolysiss that produces ATP by substrate-level phosphorylation.
Phosphoglycerate kinase
Synthesizes cAMP
Adenyl cyclase
Breaks down cAMP
Phosphodiesterase
Precursor of Tyrosine.
Phenylalanine
Where is arginine created?
Urea cycle
2 Hormones stimulate amino acid uptake into the liver.
Glucagon
Cortisol
Spans the inner membrane, the proton channel
Fo domain
Extended out into the matrix, the catalytic subunit
F1 domain
Inhibits ATP synthase by binding to the F0 domain thus closing the proton channel, electron transport is halted.
Oligomycin
Deficiency in PKU.
Phenyalanine hydroxylase
Stimulated by diacylglycerol (DAG) and inositol trisphosphate 3 (IP3)
Protein Kinase C
Cleaves phosphodiester bonds
Nuclease
Rate-limiting step of the Pentose Phosphate Pathway
Glucose-6-P Dehydrogenase (GPDH)
Allow for interconversion of diasteromers
Epimerase
Transfers a 3-carbon fragment from one sugar to another
Transaldolase
Rate-limiting step of fatty acid synthesis (requires biotin)
Acetyl CoA carboxylase
Transfers an electron from NADPH to the heme Fe in P450, reducing the Fe(III) to Fe(II)
Cytochrome P450 reductase
Inhibited in Complex I of the ETC.
NADH dehydrogenase
Inhibited in Complex III of the ETC.
Cytochrome c reductase
Inhibited in Complex IV of the ETC.
Cytochrome oxidase
Prevents Phosphoglycerate kinase ATP production
Arsenate
Enzyme that overcomes the irreversible pyruvate kinase reaction in glycolysis.
Phosphoenolpyruvate carboxykinase
The toxic effects of cyanide are due to _________________.
inhibition of cytochrome oxidase (Complex IV)
Enzyme unique to the Pentose Phosphate Pathway
Transketolase
An enzyme that removes a phosphate from the substrate.
Phosphatase
Where are free amino acids absorbed?
Small intestine
How are fructose absorbed?
Facilitated diffusion
GLUT 2 can be found in?
Basement membrane
Transport found in Luminal membrane.
GLUT 5
How many ATP produced in ETC?
30 or 32 ATP
Cofactors required in conversion of propionyl CoA to Succinyl CoA. r
Biotin and vitamin B12
(+) delta H
Endothermic reaction
(-) delta H
Exothermic reaction
A molecule with two charges but no net charge.
Zwitterion
pH = pKa + (log[A-]/[HA])
Henderson Hasselbalch equation
Glucose + Galactose
Lactose
Glucose + Fructose
Sucrose
Glucose + Glucose
Maltose
Essential Fatty Acids
Linoleate and Linolenate
Amino acid with no side chain, functions as inhibitory neurotransmitter and inhibited by strychnine
Glycine
Infants are unable to utilize oxidized glucose (glucoronic acid) to conjugate the drug chloramphenicol(antibiotic) results in high levels and toxicity
Grey baby Syndrome
The spatial arrangement of an organic molecule that is conferred by the presence of either (1) double bonds, about which there is no freedom of rotation, or (2) chiral centers, around which substituent groups are arranged in a specific sequence.
Configuration
A spatial arrangement of substituent groups that are free to assume different positions in space, without breaking any bond, because of freedom of rotation
Conformation
Compounds that have the same composition and the same order of atomic connections but different molecular arrangements
Stereoisomer
Inhibitors that blocks NADH dehydrogenase/complex I.
AMYTAL
Rotenone
Piericidin
Inhibitors that blocks complex III by preventing the oxidation of ubiquinol.
Antimycin A
reversible inhibitor of cytochrom oxidase, binds to Fe3+ heme group.
Cyanide
Compound in rat poison that inhibit aconitase.
Fluoroacetate
Found in brain; Highly expressed in erythrocytes and high affinity for glucose
GLUT 1
low affinity transporter, liver
GLUT 2
high affinity transporter, brain
GLUT 3
insulin sensitive, adipose and muscle
GLUT 4
main type CT, bone, teeth, encapsulated organs resist force, tension and stretch
type I collagen
cartilage resists intermittent pressure
type II collagen
found in reticular fibers scaffolding for specialized cells
type III collagen
basement membrane and filtration
type IV collagen
skin, eye, etc connects basement membrane to ECM
type VII collagen
The linear sequence of amino acids.
Primary Structure
The association of two or more polypeptides into a multi-subunit complex.
Quaternary Structure
Localized organization of parts of a polypeptide chain (e.g., the alpha helix or beta-pleated sheet).
Secondary Structure
The overall, three-dimensional arrangement of the polypeptide chain.
Tertiary Structure
covalent bond between two cys joining the subunits together
Disulfide bond
The result of the misfold is an abnormal haemoglobin (HbS); the switch from Glu to Val causes the cell to want to stabilise (protect the hydrophobic regions) resulting polymerisation
Sickle cell disease
Protein that can fold in multiple, structurally distinct ways, at least one of which is transmissible to other prion proteins; found on the surface of cells
Prion
21st amino acid; non-coded amino acid; encoded by subset of STOP codons, contains Se instead of S; reduced pKa useful for enzymes in anti-oxidant activity
Selencysteine
Carbon attached to the original carbonyl group in cyclic form
Anomeric carbon
N-terminal of amino acid
Amino group
C-terminal of amino acid
Carboxyl group
The only form found in proteins
L-form amino acids
Activation energy
ΔG
Study of the rate of an enzyme catalysed reaction and how it varies.
Enzyme kinetics
Initial reaction velocity, measured as soon as a substrate is mixed; rate of formation of the product.
V0
Vo=(Vmax[S])/(Km+[S])
Michaelis-Menton equation
Rearranging the Michaelis-Menten equation to the form y=mx+c; 1/Vo = (Km/Vmax[S]) + 1(Vmax); adds graphical value to the constant; can be used to determine the Km and Vmax as well to determine the action of enzyme inhibitors
Lineweaver-Burke plot
One of the most common forms of regulation; good way of controlling enzyme activity; sigmoid curve (compared to hyperbolic curve of M-M kinetics); slow to start, but more rapid change that reaches Vmax quicker.
Allosteric regulation
Also acts as a positive allosteric regulator of phosphenyolpyruvate to pyruvate (a later step in glycolysis);
Fructose 1,6-bis phosphate
Large polymeric oligosaccharides, formed by the linkage of multiple monosaccharides are called
Polysaccharides
What is the simplest aldose sugar?
Glyceraldehyde
The interconversion of alpha and beta forms of a sugar (which occurs slowly in a solution) and leads to an equilibrium mixture of the two forms.
Mutarotation
Shape of the graph of the Michaels-Menten equation.
Hyperbolic
What is the relationship between the Michaels-Menten equation and the Lineweaver-Burk equation?
The LBE is a double reciprocal equation of the MME so as to give a linear graph to correctly identify the Km and Vmax.
Vmax is unaffected but Km is increased.
Competitive inhibition
Vmax is decreased but Km is decreased.
Uncompetitive inhibition
Km is unaffected but Vmax is decreased.
Non-competitive inhibition
Interactions are the most important in the folding of the peptide chain.
Hydrophobic
Independent folding region that allows 1 protein to have multiple functions. Each domain has a specific function.
Domain
Aid in protein folding during synthesis. They also prevent misfolding and protein aggregation
Chaperones
What is ATP cleaved to for liberating energy?
ADP and Pi
Final electron acceptor.
Oxygen
Where does oxidative phosphorylation occur?
Inner Mitochondria
The largest complex in the chain.
Complex I: NADH-Q Oxidoreductase.
