Biochem Test 5

aknight1302's version from 2015-12-04 04:36


Question Answer
What are the 4 hard tissues?Bone, Dentin, Cementum, and Enamel
What hard tissue contains NO COLLAGEN?Enamel
What hard tissue has the greatest INORGANIC composition?Enamel
What are two of the proteins found in enamel?Enamelin and Amelogenin
Deposition of inorganic minerals is called ___Mineralization
Approximate formula of HydroxyapatiteCa10(PO4)6(OH)2
Apatites (what shape of crystal structure)hexagonal in cross-section, long plate-like prisms
Which of the 4 hard tissues have the largest HYAP crystals?enamel
What is the benefit of the size of bone HYAP crystals relative to enamel HYAP crystals?bone has small HYAP crystals with increased surface area ratio, allowing for greater mineralization and demineralization for body's calcium control
What is the HYDRATION of HYAP crystals?a layer of water sheathing the apatite structure
Difference between Biological Apatites and otherwise occurring Apatites?biological appetites have many SUBSTITUTIONS into the HYAP structure
What can substitute for Calcium in biological apatatites?Na (Sodium) (also Mg, but too much is disruptive)
What can substitute for Phosphate in biological apatites?Carbonate
What can substitute for OH in biological appetites?Cloride or Fluoride
What percentage of Phosphate is substituted for in bones and teeth?3-6% substituted by Carbonate
What hard tissue type has the lease substitution of HYAP (except for fluoride)?Enamel
What effect does substitution with Carbonate, Mg, or Na have on hyrdroxyapatite?greater susceptibility to ACID and greater SOLUBILITY
What effect does substitution with Fluoride have on HYAP?promotes remineralization and repair, crystal is more tightly packed, decrease solubility
If Qsp > Ksp then...solid will precipitate
If Qsp < Ksp then...solid will dissolve
If Qsp = Ksp equilibrium, solid does not dissolve or precipitate
Heterogeneous activationcrystal seed... lowers activation energy of crystallization
What alternative form of Calcium and Phosphate are we likely to see in carious dentin?Whitlockite (TriCalcium Phosphate)
What is concentration of HYAP substituents in saliva and serum relative to biological HYAP (in dentin, enamel, bones)?serum and saliva are supersaturated. crystal formation is spontaneous
At what pH and below does HYAP begin to become soluble?5.2-5.5
Regulators of Calcium and Phosphate levels in serum ___, ___, and ____Vitamin D metabolites, PTH, Calcitonin
What are some biological inhibitors of HYAP formation ___ and ___Statherins and Pyrophosphatases

Dentin bonding/mechanical force

Question Answer
Type of bond strength testing done in the 80's and 90'sSheer Bond Stength test
In terms of bond strength... the ____ the bond the greater the strengthsmaller
Tensile strength test that breaks up tested material into 1mm sticksMicro-tensile strength test
What was the problem with the Sheer Bond Strength test?it created and measured torque, in addition to its intended strength, corrupting results
How was micro-tensile bond strength affected after 6-12 months in OIL?it was unaffected in oil
How was micro-tensile bond strength affected after 6-12 months in WATER?Micro-tensile bond strength was considerably lower
MMP's (what does the string of letters mean?)Matrix Metallo-Proteinases

Cell Signaling

Question Answer
Transduction Pathway (define)the transmission of a signal, such that it changes its medium of communication. In cell signaling, this is done via a LIGAND and RECEPTOR, where the ligand carries the signal to the receptor. From here the signal continues, but through other carriers and events, toward its final target.
Hormonal Signalinglong distance signaling, usually carried via the bloodstream
Signals released by one organ and affecting totally different organ are most likely ____ signalsHormone (INSULIN as an example)

cell cycle regulation/apoptosis

Question Answer
What are the 4 Phases of Cell Cycle?GSGM. 1. G1 Interphase 2. Synthesis Phase 3. G2 Interphase 4. Mitosis Phase
What happens in the 1st phase of the Cell Cycle?G1 Interphase: Growth after division, in preparation for DNA replication
What happens in the 2nd phase of the Cell Cycle?Synthesis Phase: replicate all of the cell's DNA
What happens in the 3rd phase of the Cell Cycle?G2 Interphase, Growth and storing up nutrients for division
What happens in the 4th phase of the Cell Cycle?Mitosis Phase: dividing cell's contents into two daughter cells
What are the 5 phases of Mitosis?Pro, Prometa, Meta, Ana, and Telo-phases (PPMAT, like "pee pee mat")
What 3 things happens during Prophase?Chromosomes condense, Nucleoli disappear, Mitotic Spindle forms
What 2 things happen during Prometaphase?Nuclear envelope breaks down, Chromosomes attach to Mitotic Spindle
What happens during Metaphase?Chromosomes lined up at equatorial plane (chromosomes "maximally contracted")
What 2 things happen during Anaphase?Centromeres split, Sister chromatids separate and are pulled to polar ends
What 3 things happen during Telophase?Chromosomes decondense, nuclear membrane reforms, CYTOKINESIS
What are the protein signals that promote cell growth and division INTERNALLY?Cyclins (promoting factors)
What are the protein signals that promote cell growth and division EXTERNALLY?"growth factors"
What is the PRIMARY mechanism for control over cell growth and division signals?Phosphorylation via KINASE enzymes
Without external growth and division signals, cells will remain in which Cell Cycle phase?Prolonged G1 Interphase (aka G0 phase) (G1 Cyclins are destroyed in mitosis)
Most human cells are in which cell cycle phase?G0, (prolonged G1 Interphase)
What 2 types of cells are arrested in G0 and can never divide?Nerve cells and Muscle cells
Uncontrolled cell division leads to ____Cancer
Cell Division is controlled internally by what 3 things?CDK (Cyclin Dependent Kinases), Cyclins (Kinase Regulatory proteins), and CDK/Cyclin Complexes (the two together)
What is the Mitosis Promoting Cyclin?Cyclin B (aka MPF, Mitosis Promoting Factor) ( easy to remember b/c B is second of the two active cyclins, A being the first in cell cycle during Synthesis Phase)
What is the Synthesis Promoting Cyclin?Cyclin A (aka SPF, Synthesis Promoting Factor)
Genes for what regulatory proteins have been HIGHLY CONSERVED?CDK's and Cyclins
What type of regulatory protein acts to inhibit cell cycle progression?CDKI's (Cyclin Dependent Kinase INHIBITORS)
What are the 3 Cell Cycle Stop/Go checkpoints?G1/S (can DNA synthesis begin?) G2/M (Has DNA synthesis been completed correctly?) Spindle Checkpoint (are chromosomes attached, and can chromatids separate?)
What are the INTERNAL signals of the G1/S checkpoint?has cell grown sufficiently? Does the cells have sufficient nutrition for S-phase?
What are the EXTERNAL signals of the G1/S checkpoint?GROWTH FACTORS
What are the 2 TRANSCRIPTION REGULATORS that can act as TUMOR SUPPRESSORS?p53 and pRb
A faulty p53 gene will lead to what outcome?CANCER (no longer regulates and corrects DNA, nothing to stop problem DNA from proliferating)
What is pRb? (what does it stand for)Retinoblastima Gene product
What does pRb regulate?governs entry into S-phase
What three external signals lead to cell death?FasL, TNF, TGF
HPV inactivates what tumor suppressors in the cell?p53 and pRb
What is an example of an ONCOGENE that can cause cancer when mutated?RAS genes
A failure of cell division control causes ____CANCER
In order for something to be cancerous it MUST shut down what?p53
Metastasisspreading of tumor from one tissue to another (metastasizing)

nucleotide stuffz

Question Answer
What are the 6 critical functions of NUCLEOTIDES?1. Genetic information (DNA and RNA) 2. Energy (ATP and GTP) 3. CO-FACTOR components (NAD, FAD, CoA, SAM) 4. "Activated Intermediates" (UDP-Glucose in Gycogenesis) 5. Metabolic Regulators (cAMP, cGMP) 6. Phosphate Donor (signal transduction) (ATP)
What are the 3 components of a NUCLEOTIDE?1. Nitrogenous Base 2. Pentose sugar (ribose sugar) 3. Phosphate groups (one or more)
What are the components of a NUCLEOSIDE?Nitrogenous base and Ribose sugar
What feature distinguishes a RIBOSE from a DEOXYRIBOSE sugar?C2 has an OH group on ribose
What feature distinguishes a DEOXYRIBOSE from a RIBOSE sugar?C2 has no OH group on deoxyribose
Phosphate is USUALLY linked to what position on a NUCLEOTIDE ?Carbon-5 (is where phosphate is USUALLY linked on a NUCLEOTIDE)
Where is Phosphate USUALLY linked on a NUCLEOSIDE?(TRICK QUESTION!) NUCLEOSIDES do NOT have phosphate groups linked to them
What are three positions that a phosphate can be linked on a nucleoside (from most likely to least likely)C5 (90%), C3 (second most likely), C2 (least likely)
What are the two types of Nitrogenous bases?Purines and Pyrimidines
What Nitrogenous base is comprised only of a 6 member ring?Pyrimidine
What Nitrogenous base is comprised of two rings (6 member and 5 member ring)Purine
Where on a Ribose sugar is a Nitrogenous base bonded?Nitrogen 1, or position 1 (same for both Purine and Pyrimidine)
Where on a Pyrimidine ring is ribose sugar attached?position number 1 (Nitrogen 1)
Where on a Purine ring is ribose sugar attached?position number 9 (Nitrogen 9)
What are the different Pyrimidines?(there are 3) Uracil, Thymine, Cytosine
What are the different Purines?(there are 2) Adenine and Guanine
What Nitrogenous base does RNA have, but DNA not have?Uracil (instead of Thymine)
What Nitrogenous base does DNA have, but RNA not have?Thymine (instead of Uracil)
What Purine metabolic products come from Purine catabolism?Xanthine and Hypoxanthine
Where do Phosphates attach to Nitrogenous bases?(TRICK QUESTION!) Phosphates do NOT bond directly to Nitrogenous Bases
What parts comprise GUANOSINE?Ribose (not de-oxy) + Guanine
What parts comprise DEOXYGUANOSINE?Deoxy-ribose + Guanine
What parts comprise GUANOSINE MONOPHOSPHATE?1 phosphate + ribose + Guanine
(overview) Salvage of Purines --> what 3 products?PRPP + free nucleoside + URATE
(overview) Salvage of Pyrimidines --> what 3 products? :PRPP + free nucleoside + urea (very little in humans, mostly in bacteria)
Question Answer
hypoxanthine and xanthine are formed during the catabolism of what type of nucleotides?purines
Gout is caused by build up of ___ which is a product of _____Uric acid (urate), Purine catabolism
hyperactive PRPP synthase leads to what condition?Gout
what is drug treatment for Gout?Allopurinol
Allopurinol is prescribed for what?Gout
What disease-deficiency has same symptoms as Gout?Lesch Neehan
defect in HGPRT causes what disease?Lesch-Neehan
ADA Immunodeficiency (caused by defects in what?)Adenosine Deaminase
anti-cancer drug (nitro base analog)fluorouracil
anti-viral durg (nitro base analog)Zidovudine (AZT) (thymidine analog)


Question Answer
suffix -ine for nitrogenous base mimeans?only the nitrogenous base
suffix -osine for nitrogenous base (purine) means?nitrogenous base plus sugar
suffix -imidine for nitrogenous base (pyrimidine) means?nitrogenous base plus sugar
suffix -ylate for nitrogenous bases means?monophosphated nucleotide (at 5' position) called ACID SALTS

some denovo

Question Answer
Two types of pathway for NUCLEOTIDE SYNTHESISDe Novo (from new, ENERGY EXPENSIVE) and Salvage (recycle old nucleic acid, ENERGY ECONOMICAL)
What is the first step of De Novo Purine Synthesis?PRPP synthetase converts Ribose5P --> PRPP (rate-limiting step of De Novo Purine Synthesis)
What is the rate-limiting step of De Novo Purine Synthesis?PRPP synthetase converts Ribose5P ---> PRPP (also the FIRST step of De Novo Purine Synthesis)
What are the steps of De Novo Purine Synthesis?1. PRPP Synthetase 2. create 5 membered ring 3. add to 6 membered ring 4. Now have Inosine MonoPhosphate (IMP) which can be changed into any Purine Nucleotide (Adenine or Guanine)
What is the first step of De Novo Pyrimidine Synthesis?creation of CARBAMOYL PHOSPHATE
What are the Denovo Synthesis precursors for each Nitrogenous base type (purine and pyrimidine)?IMP (purine) OMP (Pyrimidine)
What is the committed step of Purine De Novo Biosynthesis?Production of Phosphoribsyl-1-amine (Nitrogen # 9 of Purine on ribophosphate is product)
Where does the Nitrogen 9 of Purine come from?Glutamine (glutamine-PRPP-amidotransferase) (committed step)
(question) What are the two differences between Carbamoyl Phosphate in Urea cycle and Pyrimidine synthesis?1. Reaction in Urea happens in mitochondria, Pyrmidine synthesis in cytoplasm 2. carbamoyl phosphate from ammonia in urea cycle, carbamoyl phosphate from GLUTAMINE in PYRIMIDINE synthesis
what is committed step of PYRIMIDINE DE NOVO SYNTHESIS?formation of N-Carbamoyl-aspartate (aspartate and carbamoyl phosphate react) (2nd step)
Pellagra is caused by deficiency ofTryptophan, (caused by deficiency of its derivative, NIACIN)

more fun synthesis rxns

Question Answer
Inosinate (IMP) + ____ + ____ --> Adenylate (AMP) (Adenine Monophosphate) what are missing reactantsAspartic Acid + GTP
Inosinate (IMP) + ____ + ____ --> Guanylate (GMP) (Guanine Monophospate) what are missing reactantsGlutamine + ATP
Inosinate (IMP) + Aspartic Acid + GTP --> ____Adenylate
Inosinate (IMP) + Glutamine + ATP --> ____Guanylate
What reactant is needed to convert RNA to DNA?NADPH

de novo origins

Question Answer
Nitrogen # 7, C 4,5 (purine) comes from what?Glycine
Carbon 8 of purine comes from what?formyl tetra hydrate (turns GAR into FGAR)
Nitrogen # 3 (purine de novo synthesis) comes from what?glutamine (this is 4th step) (interacts w/ FGAR)
What is needed to close the 5 member ring of Purine?ATP (reactant)
Nitrogen at 1 comes from what (purine denovo)Aspartate
Carbon at 2 comes from what (purine denovo)formate
Nitrogen at 3 comes from what? (purine denovo)Glutamine
Carbon at 4 comes from what? (purine denovo)Glycine
Carbon at 5 comes from what? (purine denovo)Glycine
Carbon at 6 comes from what? (purine denovo)CO2
Nitrogen at 7 comes from what? (purine denovo)Glycine
Carbon at 8 comes from what? (purine denovo)Formate
Nitrogen at 9 comes from what? (purine denovo)Glutamine