Biochemistry EXAM Flashcards

Terms Definitions
Oligomeric
Multisubunit
DNA
deoxyribonucleic acid
Non-polar Proteins
(Hydrocarbons)GlycineAlanineValineLeucineIsoleucineMathioninePhenylalanineTryptophanProline
Km
Michaelis Menten constant
carbohydrate
monosaccharides, disaccharides, and polysaccharides
source of immediate energy for the body
Elements in a lipid
C=carbonO=oxygenH=hydrogen
Nucleotide
monomer of nucleic acid
monomer
chemical subunit to build polymers
Monosaccharide
Monosaccharide - Monomer of Carbohydrates.
beta-sheets
6 aa residues per strand
DNA polymerase III
Major replicative polymerase
unicellular
one cell completes all tasks
polymer
large molecule of identical monomer joined together in a chain
isomer
organic compounds with same molecular formula but different structures and properties
Which carbon isotopes are unstable
carbon 14
alpha-helix
rise= 0.15 nm
pitch = 0.54
3.6 residue per turn
Turns
Loops containing 5 residues or less
5
How many R-groups per active site?
2 Types of Sugar
Ribose (RNA)
Deoxyribose (DNA)
Hydrocarbons
compound containing only hydrogen and carbon
Photosynthesis
the synthesis of complex organic materials, esp. carbohydrates, from carbon dioxide, water, and inorganic salts, using sunlight as the source of energy and with the aid of chlorophyll and associated pigments
hydrocarbon chain
chain of elements containing only hydrogen and carbon
a _______ forms 4 fused rings; cholesterol is an example of one.
steroid
what is the inducer of Beta galactosidase
IPTG
Enzyme
Enzyme - Protein catalyst that assists chemical reactions.
Secondary structure
Structure maintained by hydrogen bonds between amide hydrogens and carbonyl oxygens of the peptide backbone. Major structures include the alpha-helix and beta-strands
amphipathic lipid
Surface Dilution Kinetics enzymes have these kinds of substrates, activators, and inhibitors.
What direction to read DNA in
5'-3' direction
Observation
first step to scientific method / taking in information using five senses
eukaryote
Any organism having as its fundamental structural unit a cell type that contains specialized organelles in the cytoplasm, a membrane-bound nucleus enclosing genetic material organized into chromosomes, and an elaborate system of division by mitosis or mei
peptide bond
the covalent linkage between two amino acid units in a polypeptide; formed by dehydration synthesis
the substrate that fits into a particular region of an enzyme called the _____
active site
Define operon
a coordinated unit of gene expression. Include a cluster of structural genes which envode products involved in a set of related processes plus regulatory elements which control their expression. 2-6 genes norm but can be 20 +
1) How are non-heme Fe absorbed?
 
2) non-heme Fe is bound to what before absorbed into enterocyte?
1) DMT1
 
2) mucin
 
Henderson-Hasselbalch Equation
pH = pKa + log[A-]/[HA]
 
Used to determine the final pH of a weak acid solution once the dissociation reaction reaches equilibrium
When the enzyme denatures.
Enzymatic reactions behave similarly up to this point.
Uncompetitive Inhibition
Occurs when the inhibitor will only bind to the ES complex
DNA Replications occurs in?
S-phase of the cell cycle
Acid Precipitation
sulfuric acid and nutric acid from burning fossil fuels
standard free-energy change
The free-energy change under standard conditions of temperature, pressure, pH and concentration of reactants.
Which antibiotics act on ribosomes
all but ampicllin and carbicillin
NEGATIVE REGULATION
What are the roles of repressors?
bind DNA and blocks transcription
(ligand can activate or inactivate)
10^-13 seconds
This is how long the transition state is stable.
Control group
a factor that does not change, used for comparison
what are the 4 antiobiotics we talked about
1. Ampicillin (Carbenicillin)2.Chloramphenicol3. Kanamycins4. Tetracycline
What is Rifampins action?
Rifampin binds to prokaryotic RNA poly but NOT eukaryotic versions
 
BACTERIAL GROWTH SLOWS w/out interfering w/ RNA syn in pateint
Which of 6 major enzyme classes
1st integer in E.C. name
characteristics of organic compounds
most organic compounds are built by linking together monomer into polymers
1) What does TfR mediate?
 
2) Where is TfR abundant?
 
3) How does TfR function?
 
4) When does TfR release Fe?
 
5) What is returned to ECF and plasma membrane?
1) mediates cellular uptake of Fe-transferrin
 
2) hepatocytes, immature erythrocytes, malg/non malignant rapidly dividing cells
 
3) TfR endocytoses TFR transferrin-Fe complex creating an endosome
 
4) TfR releases Fe as endosome is acidified
 
5) apotransferrin and TfR
Carbony C and N is ___ than C-N single bonds but ____ than C=N double bonds
shorter, long
The relationship between k and Ea
What does the Arrhenius Equation show?
what are type 1 endonucleases
cut at random sites when DNA loops back to bound enzyme
Replic Fork: Leading strand
3) 5' to 3' polymerase activity of another DNA poly then fills the resultant gaps with DNA and what joins the tow fragments?
 
4) DNA ligase seals broken phosphodiester bonds by what/using what?
3) DNA ligase
 
4) activating 5' end w/ATP and then coupling ATP hydrolysis to form new phosphodiester bond
Name the four noncovalent bonds from strongest to weakest
Charge-charge > Hydrogen bonding > Hydrophobic interactions > Van de waals
what is the differrence between restriction endonucleases and modification enzymes
they both are defense systems, but the endonuclease cleaves while the modification enzyme methylates.
1) DNA binding proteins fit into major and minor grooves and recognize bases by forming what?
 
2) What fits in the major groove?
1) non-covalent bonds w/bases in groove
 
2) alpha helixes fit in major groove
GLU, HIS, LYS, ASP, TYR, CYS
Amino Acids that act as acid catalysts when pronated
1) Loop 2
 
2) Does loop 2 inhibit transcription of ALA-S2 as with ALA-S1?
1) Heme inhibits Fe uptake of Fe-transferrin complex
 
2) NO it does not inhibit transcription
 
Why is Fe always bound to proteins within the body?
Fe is always transported or stored as Fe(ferric) b/c unbound Fe can generate highly reactive
FREE RADICALS
 
Can cause tissue damage(HO-)
1) Heme Fe are taken into cell where/how?
 
2) What is it degraded into what and releasing what?
1) taken up on the luminal surface of enterocyte (mucosal cell)
 
Heme Fe is taken up intact
 
2) degraded to bilirubin releasing Fe into enterocyte
Ethanol
Hept-
Seven Carbons
Arm
used for support
 
 
 
Carbohydrates
(mono/disaccharides)
 
 
 
monosaccharides: C6H12O6- glucose, galactose, fructose
disaccharides: dehydration synthasis - glucose + glucose --> maltose + H2O- glucose + galactose --> lactose + H2O- glucose + fructose --> sucrose + H2O
Histones
Major chromatin proteins
Highly conserved
 
cofactor
nonprotein structure that helps enzymes catalyze
Hexokinase
This enzyme catalyzes the phosphorylation of D-glucose
Enantiomers
Variations in spatial arrangements around an assymetric carbon, which results in molecules that are mirror images of one another. They cannot be superimposed on one another.
Cohesion
attraction of water with water
 
 
 
Proteins
amino acids (peptide bonds) --> polymers
carboxyl group + amine group + R group
growth and repair
signaling
defense
catalyzing chemical reactions
meat and nuts
Galactose
Galactose - Monosaccharide found in milk.
X-ray crystallography
Used to determine the three-dimensional conformation of proteins via crystals
Amphipathic
Molecules that are both hydrophilic and hydrophobic. Contain a polar group with a hydrophobic tail
Energy Storage, Quick retrieval of energy, and easily broken down are uses of ______
Carbohydrates
Triose Sugars
C3H6O3Aldose - GlyceraldehydeKetose - Dihydroxyacetone
organic chemistry
molecules that contain a carbon/hydrogen combonation
saturated fat
hydrocarbon chain that contain the maximum number of hydrogen and therefore have no double covalent bonds
they solidify at room temperature
a substrate that accelerates the rate of a chemical reaction is a(n) _______
catalysts
Peptide
Peptide - Covalent bond that joins amino acids.
How is trp operon expression regulated?
 
At high levels of trp how is transcription terminated?
 
Does rate of translation affect mRNA structure?
attenuation-concurrent transcri/translation
 
mRNA folds into terminator sequence and no trp syn occurs
 
yes by change in transcription rate
Ligases
Catalyze ligation or JOINING of two substrates. Requires ATP. Usually refers as synthetases
pH
This effects the ionizable state; it influences active site structures and effects enzyme efficiency
Structural Isomers
Variation in covalent partners, in which each share the same molecular formula, but have a different arrangement of atoms.
Ecosystems
 system formed by the interaction of a community of organisms with their environment
what is a protein monomer called?
amino acid
mutation
A heritable change in the nucleotide sequence of a chromosome.
base
a substance with a decreased number of Hydrogen ions concentrated in a solution
a carbohydrate made up of 2 sugar units is a(n) _____
disaccharide
what are shuttle vectors
plasmids transferring genes between two organisms. Prokaryote and eukaryote. Unique origins of replication for each cell type. selectable markers for each cell type.ampicillinclone eukaryotic genes in prokaryote, but express in eukaryotes.
A-T base pairs formed by how many H-bonds
2
Formation of a peptide bond
Eliminates the ionizable alpha-carboxyl and alpha-amino groups of the free amino acids EXCEPT for those at the amino & carboxyl termini
"Suicide" Inhibitors
These become reactive after binding to active site
Covalent bonds
bonding that results when atoms share electrons
free-energy change
The amount of energy released or absorbed in a reaction.
Describe basic steps of Western blotting
1. SDS-polyacrylamide gel electrophoresis2. Transfer proteins to nitrocellulose membranes3. use specific antibody to identify target protein.
What does ADR mean?
Adverse drug reactions which are linked to genetic variations btwn individuals known as polymorphins
Hydrogen acceptor
Atom to which H is less tightly associated. O or N. The acceptor has partial negative charge that attracts H atom
Low
Which is more stable? Low MW enzymes, or high MW enzymes?
Water looks like what and which end is positively charged?
what are the four distinct groups attached to a carbon atom for protein monomers?
hydrogenCOOHgroup Ramino group
what is the enzyme atached to the goat enzyme
alchaline phosphatase
Telomerase activity is regulated for what?
protective mechanism to prevent uncontrolled cell proliferation of abnormal cells
 
"cancer cells have increased telomerase activity"
Theoretical Max Efficiency
This is the term for when every collision of E and S gives ES
give examples of unsaturated fats.
1. olive oil2. corn oil3. veggie oil
What are the 3 parts of Hb molecule that must be available for syn of Hb?
Fe, heme, globin
Rotation around C-N bond 
is restricted due to the double bond nature of the resonance hybrid form
how are protein monomers reconized?
a central carbon atom with for distinct groups attached
How does tetracycline work
They bind to a single site on 30 ribosomal subunit- preventing binding of aminacyl-tRNA to acceptor site. Protein synthesis is blocked.
Nucleotides triphosphates are joined together how?
C3 of one nucleotide linked to C5 carbon of next nucleotide via Pi
 
Type and Arrangement of amino acid R-group in active site
This determines the substrate molecule that can bind and react
Why is DNA more stable than RNA
because the Thymidine has a methyl group on its ring
Replication fork: leading strand
1) to make lagging strand continous the RNA primers are degraded via what?
 
2) how does it work?
1) 5' to 3' exonuclease act of DNA pol
 
2) removes ribonucleotides from 5' end of Okazaki fragment
What is the difference between a saturated fat and an unsaturated fat?
Saturated fats have only single bonds, and unstaturted has some double or triple bonds
Binding of TBP to TATA box causes what?
severe bending of the DNA which destabilizes to help unwind
Can SNPs be found within the coding region? If so what happens?
Yes SNPs can be found within coding regions causing a change in coding sequence
1) what is the problem seen in eukaryotes that DNA poly can't do?
 
2) why is this?
 
3) What fills the gap b/c there is no 3' OH to extend from?
1) extend the extreme 5' end of the lagging strand
 
2) RNA primer runs out of room for last Okazaki fragment
 
3) telomeres-tandem repeats of G-rich sequences
hydroxyl
-OH alcohol
Hyperchylomicronemia
Excess chylomicrons
ion
a charged atom
Name stop codons
UGA
UAA
UAG
Autosomal recessive patterns
Often:
Monomers
-connected via condensation reaction
-broken via hydrolysis
pH of acid rain
1.5-5.4
______ weakens protein interactions
salt
transcortin
Corticosteroid binding globulin ______carries cortisol
Codominance
Neither allele is dominant
CETP
Cholesterol ester transfer protein
ATP
(adenosine triphosphate) a common source of activation energy for metabolic reactions, basically an adenine and 3 phosphate groups
PFK
 
phosphofructokinase
Tetramer with allosteric binding sites
-ATP binding with allosteric site reduces enzyme activity
-AMP binding with allosteric site increases enzyme activity
 
PFK activity increases when ATP/AMP ratio decreases
 
at low ATP
-R state favore, high affinity
-catalytic sites are occupied, but not the allosteric sites
 
at high ATP
-low affinity
-sigmoidal curve
-allosteric sites are occupied
 
Albinism
Congenital deficiency of Tyrosinase (inability to synth melanin from tyrosine) or defective tyrosine transporters; inc risk of skin cancer
location of retinoblastoma gene
chromosome 13
selenium
Occurs as selenomethionine and selenocysteinePart of Glutathione peroxidase, type I iodothyronine 5-deiodinase, selenoprotein P & selenoprotein WDeficiency –during parenteral nutrition, lactation, deficiency in dietChronic muscle pain, abnormal nail beds, and cardiomyopathy ( Keshan’s disease)Excess –cirrhosis, splenomegaly, gastrointestinal bleeding and depression
energy
the capacity to do work
DNA damage:
-Dimerization by UV radiation
-Methylation
-Deamination
-Intercalation
Place where repressors bind
Enhancer region
ribose
a white, crystalline, water-soluble, slightly sweet solid, C5H10O5, a pentose sugar obtained by the hydrolysis of RNA.
protein structure
very complex
sequence of amino acids
basic three dimensional shape
folding over process held in place by a variety of types of bonds
interaction between different polypeptide chains
*This gives proteins an incredibly wide range of overall apperances and functions
inorganic compounds
don't generally contain carbon atoms
products
Ending materials in a chemical reaction.
Ice
water expands [because water molecules are kept seperated], and becomes less dense
floats in liquid water
glycolysis
anaerobic breakdown of glucose to pyruvate
 
set of 10 reactions
 
occurs in cytoplasm
Edwards
Trisomy 18, most common trisomy resulting in live birth after downs1:8000severe MR, rocker bottom feet, micrognathia, low set ears, clenched hands, prominent occiput, congenital heart diseasedeath within 1 year of birth18 election age
Proteasome
-control proteins key in regulatory processes in the cells' physiological processes-proteins are targeted by enzymatic attachment of ubiquitin molecules-N-terminus AA as well as phosphorylation render proteins susceptible to ubiquitination & subsequent destuction
Major carbohydrates in the diet
lactose
sucrose

starches
amylose
amylopectin

fiber (products we cant digest like cellulose that come from cell walls)
Effect of anabolic steroids of steroid receptors
receptor agonists
C-II
contains all the lipoproteins and activates LPL
cholerae
what toxin activate the adenylyl cyclase cascade, with potentially disastrous consequences
What enyzyme introduces negative supercoiling?
DNA gyrase
The products of the tricarboxylic acid cycle are CO2 and:a. 3NADPHs, 1FAD, and 1ATPb. NAD+c. NADPHd. 3NADH, 1FADH, and 1GTP
D
Topoisomerases
Control of topological state (linking number) of DNA
4. Glutamate --> UREA CYCLE
Urea cycle
interaction
two things acting upon each other
glucose
a sugar, C6H12O6, having several optically different forms, the common dextrorotatory form
Essential Fatty Acids are:
PUFA (polyunsaturated fatty acids)
Catalyst
another term for a substance that speeds up chemical reactions( may be organic or inorganic)
structural formula
an expanded molecular formula showing the arrangement of atoms within the molecule
_____ are made form nucleotide subunits which store and carry information
nucleic acids
Organic compounds
Are compounds that contain carbon. There are four classes of organic compounds: carbohydrates, lipids, proteins, and nucleic acids.
What chromosomal translocation is associated with follicular lymphoma?
t(14,18)increased Bcl-2 expression
Base excision repair
specific glycosylases recognize and remove damaged basesAP endonuclease cuts DNA at pyrimidine site, empty sugar is removed and gap is filled and resealed
Irreversible Enzyme inhibitors
heavy metals, aspirin, fluorouracil, organophosphates
A DNA library derived from mRNA
cDNA library
For the purposes of gluconeogenesis, what causes PK to be shut down?
alanine
ATP content
Symptoms of scurvy

due to defective collagen biosyn.
defective bone formation (infants) (bow legs)
swollen, bleeding gums,
bruising
poor wound healing
Effect of Rifampicin
block prokaryotic RNA polymerase initiation
Cat 1 deficiency
this deficiency affects primarily liver – fasting hypoglycemia
prosthetic group
If the coenzyme is permanently associated with the enzyme and returned to its original form, it is called a
378. What vitamin is pyridoxal phosphate?
Vitamin B6
neutron
particle with no charge in the nucleus of an atom
Two key aminoacids in the catabolism of the amino group of the aminoacids are glutamate and _____. a. phenylalanineb. glycinec. serined. asparate
D
Non-Watson Crick base pairs:
A-A pair
A-T Hoogsteen pair
Hypothetical T-C pair
G-U Wooble pair in RNA structures
2. Thiosulfate *Grabs CN- from methemoglobin to form THIOCYANATE*Excreted in urine
Methemoglobinemia treatment
polysaccharide
a carbohydrate, as starch, inulin, or cellulose, containing more than three monosaccharide units per molecule, the units being attached to each other in the manner of acetals, and therefore capable of hydrolysis by acids or enzymes to monosaccharides.
Organic
type of compound containing both C and H
Hydrogen bonds
a positively charged hydrogen atom in one covalent molecule is attracted to a negatively charged area of another
chemical bonds
the attractive forces that hold atoms together
Nucleic Acids
RNA - ribonucleic acid. DNA - deoxyribonucleic acid. Polymers consisting of chains and nucleotides. Nucleotides consist of sugar, phosphate, and nitrogen base.
bicarbonate ion
the most important buffer in human blood is the bicarbonate
What disease is caused by mutations in mismatch repair genes leading to dinucleotide repeat instability?
HNPCC
Kartagener's syndrome
immotile cilia due to dynein arm defectmale and female infertility (sperm immotile), bronchiectasis, and recurrent sinusitis (bacteria and particles not pushed out)associated with situs inversus
ATP roles
**most abundant of the nucleotides in the body-Biosynthesis-Movement-Ion Pumping-Present in Cofactors-->facilitate metabolic pathways
What enzyme is involved in converting UDP-galactose to UDP-glucose?
IsomeraseUDP-galactose 4-epimerase
Define glucogenic AA's
AA's who carbon backbones are converted to glucose (most AA's are glucogenic)
Common symptoms/complications of chromosome deletion syndromes
severe mental retardation
failure to thrive
Function, location of A4 apoprotein
origin- liver
lipoprotein- CM, HDL
function- activate LCAT, C transport
fumurate
Synthesis of AMP from IMP and salvage of IMP via AMP have the net effect of deaminating aspartate to ?
C2
glucose and mannose are what type of epimers?
494. What are thyroid hormones produced from?
The precursor thyroglobulin-tyr
what does water form with polar solutes?
h bonds
Homotropic effect
The effect of substrate on allosteric enzyme
Function of tears?
Lubrication and oxygenation of corneal tissues

Protection -

a) lysozyme breaks beta 1-4 linkages in bacterial cell walls

b) lactoferrin binds iron and reducing bacterial gorwth

c) tear-specific prealbumin binds retinol, and may have bacteriacidal activity

Wetting of the optical surface --> overal reduces refraction error.
Hemoglobin structure
2 alpha globin chains+2 beta globin chains+Heme
amino acid
compounds with an amino group and a carboxyle group
amino acids
basic units of proteins; consist of a carboxyl group, an amine group, and a variable (R) attached to a central asymmetric carbon atom. 20 diff amino acids.
Which cyclin regulates the G1 -> S transition?
Cyclin D
Vit B6 (pyridoxine) def
Inducible by INH and oral contraceptivesConvulsions, hyperirritability, peripheral neuropathy
The leading strand is formed by
pol delta or epsilon
Function of elastase
break on carboxyl side of small hydrophobic AA's
define and example reduced penetrance
individual who has genotype for disease may not exhibit disease pheonotype at all, even though he/she it can be transmittted to the next generation
ex: retinoblastoma
Describe uptake of carbohydrates
broken down into dissacharides by alpha amylase: maltose, isomaltase
broken down by brush border glycosidases in small intestines into:glucose
galactos
fructose

enter enterocyte via transporters
enter portal circulation
Type II familial hypercholesterolemia
LDL deficiency is characterized by what disease
NADPH needed for 3 things:
1) anabolic processes2) respiratory burst3) P-450
How many rings does a purine have? Pyrimidine?
2, 1
Porphyria cutanea tarda affects which step in heme synthesis?
uroporphyrinogen III --> coproporphyrinogen
* missing enzyme uroporphyrinogen decarboxylase, uroporphyrin accumulates in urine (tea colored), photosensitivity
What is a DNA molecule called that contains a recognition sequence?
cognate DNA
Type 1 glycogen storage disease
Problem with GLUCOSE 6 PHOSPHATASE
phospholipid
any of a group of fatty compounds, as lecithin, composed of phosphoric esters, and occurring in living cells.
biological macromlecules- form from monomers?
monomers are smaller subunits of polymers
*many carbon based (organic) molecules are made up of identical or similar subunits repeated over and over
*large molecules is usually a polymer made up of lots of smaller subunits called monomers
Indentifying Fatty Acids
Saturated fatty acid - animal fat. All bonds between carbon atoms are single bonds. Unsaturated fatty acid - plant oil. Contains at least one double bond between carbon atoms.
Wht are the four ketogenic amino acids?
Isoleucine, Leucine, Lysine, Thryptophan
the signal peptide is recognized by the _____, which stops translation temporarily.
signal recognition protein (SRP)
Definition of colloidal solution
heterogenous solution due to size of solute particles
Composition of sucrose
alpha D glucose and beta D fructose joined by alpha1-beta2 linkage
Example of pleiotropy: Marfan's syndrome, where the gene is located and what system it affects

Marfan syndrome (AD condition in fibrillin located at chromosome 15q)
tall stature, long lengthy limbs, spider fingers, arched palate
affect eye, skeleton, CV system
Mechanism of action of glucagon
pancreas sense low blood sugar
bind to plasma receptors in liver and adipose
works via trimeric G proteindissociation of protein into alpha-GTP and beta-gamma
activates adenyle cyclase
increases cAMP
activates PKA (cleave off catalytic subunit)
phosphorylate various enzymes
Resting metabolic rate
Rate of metabolism that occurs when an individual is at rest in a warm environment and is in the post absorptive statesufficient for the vital organs such as the heart, lungs, nervous system, and kidneysDetermined by:Age.GenderBody surface areaThyroid secretion
414. How is deoxyribose made?Three steps...
1. Use ribonucleotide reductase2. Reduce -OH3. Proceed by means of free radical reactions (very sensitive to free radical inhibition)
What is the name of an inactive precursor enzyme?
Zymogen / Proenzyme
How does NMP kinase work?
1. Substrate binding induces large structural changes in the kinase:

2. P-Loop closes down on polyphosphate chain: interacts w/ B-phosphoryl group

3. Movement of P-Loop brings down domain of enzyme
- Forms "lid" over bound nucleotide

4. Lid holds ATP in position
- Gamma-phosphoryl group is positioned next to the binding site for next NMP to bind

5. Binding of NMP induces more changes

** This only happens when both donor and acceptor are bound, prevents transfer of PO4 to water.
"Very Poor Carbohydrate Metabolism" (VPCM)
Von Gierke's (1) --> Glucose-6 phosphatase*G for G6P
If pH is 7, will amino acid move in electrophoresis?
No
Regulation of Pyrimidine Nucleotide de novo pathway
EUKARYOTES-first step is catalyzed by CPS II (1st committed step) [carbamoyl phosphate synthetase II)PROKARYOTES-only has CPS, producing carbamoyl phosphate used in pyrimidine synthesis and the urea cycleSecond step catalyzed by ATCase (aspartate transcarbamoylase) is the first committed stepfor both prokaryotes and eukaryotes, the 1st committed step is regulated -Inhibition on CPS II or CPS catalyzed reaction: UDP & UTP ---in eukaryotes----Inhibition of ATCase: UTP & CTP ---in prokaryotes----abundance of the purine nucleotide ATP stimulates the pyrimidine pathway and provides a mechanism for establishing a purine-pyrimidine balance
Explain why temperatures above Tm cases a gel-like phase?
Because cholesterol becomes more rigid than the fatty acid tails of the phospholipids, thus limiting disorder/fluidity
Effect of not having enough calories, esp. carbs, in the diet
increase demand to catabolize proteins
this leads to breakdown of negative nitrogen balance
Sex differences in mutation rates

DNA undergoes more replication in men than in women
pt mutations more so paternal
highly penetrant, autosomal dominant disorders usually missense mutations in the paternal germline
Abeta lipoproteinemia (acanthocytosis, Bassen-Kornzweig syndrome)
No chylomicrons, VLDLs or LDLs due to defect in apoB expression Rare defect; intestine and liver accumulate, malabsorption of fat, retinitis pigmentosa, ataxic neuropathic disease, have thorny appearance
541. What does cortisol do?
Adjust to stress by stabilizing blood glucose levels in a slower manner by inducing synthesis of various enzymes
Five common features of enzymes:
1. active site is a cleft/crevice2. active site takes up relatively small part of total enzyme volume3. active sites are unique microenvironments4. substrates bind to enzymes by multiple weak attractions5. specifity of binding depends on arrangment of atoms in active site
how can you tell if a chemical equation represents c ondensation synthesis?
the result includes water
the balance between the physiological effects of the various Eicosanoids may be manipulated by:
changing the fatty acid composition of the diet
This antitumor drug inhibits Topo II
m-AMSA(Topo II is the mom enzyme. M-AMSA makes MOM SAD)
Amylose and amylopectin are broken down by what enzyme? into what compound?
via amylase, broken down into maltose, then into two glucose units
Example of pathology where point mutation affects splicing
pt mutation in thalasemia (G to A) will produce a new 3' splice site
alpha-amanitin (from mushrooms) inhibits RNA Pol ___.
RNA Pol II --> cannot open DNA to start transcription
Why can water separate ions?
water has a high D, which is indirectly related to force. water molecules interact more strongly with ions than cations and anions can interact with ea other
Does ΔG correlate with rate?
No. It is related to the equilibrium constant of a rxn, therfore, the concentrations of reactants and products.
tissue specific metabolism of glucose
 
liver
- only organ that can carry out all metabolic functions
 
-primary function is to maintain stable blood glucose level to "feed" other tissues
 
-stores glucose in glycogen when there is a high supply and releases as needed
 
-makes fatty acids to store in adipose
 
-metabolizes amino acids, makes proteins
When would we see increases in creatine kinase?
crush muscle (increase only in M subunits)
heart attach (increase in B subunit)
What is ment when someone says DNA replication is discontinuous?
the lagging strand synthesis is discontinous by laying down segments of DNA called Okazaki fragments
Driving force of binding of oxygen to Hb
partial pressure of oxygen (dont forget oxygenated Hb is a stronger acid than deoxygenated)
500. What is the function of nitric oxide?
Activates guanyly cyclase to make cyclic GMP (a secondary messenger)
Why do DNA Polymerase I can remove primers?
Because DNA Polymerase I has 5'-->3' activity
There are certain fatty acids that our bodies cannot make and are essential, they are
Linoleic acid which is converted to arachidonic acid, arachidonic acid is the precursor to prostoglandins, prostocyclins, and thromboxanes (via the COX1 or oxogenase pathway) and leukotrienes (via the COX2 or lipogenase pathway)
If a carrier of sickle cell (with given allele frequence in blacks of 1/10) has child with random black person, what is the frequency of having a child with sickle cell?
1/10 x 2/3 x 1/4 = 1/60
Explain the h bonds in ice.
h bonds are in a straight line, of equal lengths and constant angle, individual molecules are kept apart
After a meal, high levels of insulin will _______ regulate LPL?
they will upregulate LPL so as to synthesize triglycerides
430. What is the first step in amino acid degradation?
Separation of the amino group from the carbon skeleton
What does a large Ki mean? What does a small Ki mean?
Large Ki = weak inhibition because more of the inhibitor is free

Small Ki = strong inhibition because more of the inhibitor is bound to the enzyme
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Term:
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