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Diag 4921 Bio

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Acetylene is the same as what?
ethyne
Where is the estrogen receptor located?
When stimulated by the addition of a ligand such as stilbestrol, estrogen receptor will localize within the nucleus, where it regulates genes by binding to enhancers and promoters. Radiolabelled stilbestrol would localize with estrogen
receptor in the nucleus. There is no estrogen receptor in the plasma membrane or mitochondria. Some estrogen receptor may be located in the cytoplasm, particularly in the absence of ligand, but it will localize mostly in the nucleus when it has ligand bound.
Which RNA polymerase is responsible for transcription of all mRNAs?
RNA Polymerase II
A scientist wants to separate a mixture of amino acids in a solution buffered to pH 6.0 by suing electrophresis. The mixture is composed of lysine, glycine, and aspartic acid, whcih have isoelectric points of 9.7, 6.0, and 3.0 respectively. The expected
- Lysine, glycine, and aspartic acid.
- First, it is clear that glycine will be amino acid II on the electrophoresis gel since its isoelectric point matches the
pH of the solution. This eliminates choices B and D. Since opposite charges attract each other, the positively-charged
amino acid at pH 6.0 will be amino acid I since it will be attracted to the minus charge. Lysine, with an isolelectric point of
9.7, is the positively-charged amino acid at pH 6.0, so the answer is A.
Cell membrane importance
The cell membrane is what regulates the flow of all
material into and out of the cell for all organisms.
- When you break disulfide bonds (-S-S- <=> -S-H H-S-), what kind of reaction is this?
- Of the four reagents, which one would you choose?
a. KMnO4
b. H2SO4
c. NaBH4
d. CH3CH2OH
Reduction.
Would choose C, sodium borohydride b/c both KMnO4 (potassium permanganate) and H2SO4 (sulfuric acid) are very strong oxidizing agents and CH3CH2OH (ethanol) is a poor reducing agent (and also a poor oxidizing agent).
KMnO4 is a why kind of agent?
very strong oxidizing agent.
H2SO4 is what kind of agent?
very stong oxidizing agent
CH3CH2OH (ethanol) is what kind of agent?
poor reducing/oxidizing agent.
NaBH4 (sodium borohydride) is what kind of agent?
strong reducing agent
During DNA replication, the primer is DNA or RNA?
RNA.
What are telomeres?
Special DNA sequences found at the ends of all linear eukaryotic choromosomes.
Telomerase
maintains the tolmeres during DNA replication;
T/F: Exonucleaseactivity of DNA polymerase serves as an error correction mechanism and degredes the end of chomosomes.
False.
Exonuclease activity DOES serve as an error correction mechanism.

But, it doesn't normally degrade the ends of chomosomes.
What happens in the absence of telomerases?
in the absence of telomerase, the telomeres become progressively shorter with each round of cell division.
- Since the primer is RNA, it will degrade leaving the end of the chomosome single stranded, and since this region is at the end, there is no place to put a second pirmer so that the first primer region can be replciated.
- If the 1st primer region cannot be replicated, the single stranded DNA will degrade and the end of the chomosome will become shorter.
What happens in the presence of telomerase?
- The enzyme telomerase prevents (degradation of RNA primer which makes chormosome shorter and shorter) by binding to the end of chromosomes.
- It carries a nucleotide sequence that can serve as a temporary site for primer formation; once the primer is synthesized, replication can proceed into the 1st primer region, keeping the end of the chomosome double stranded and preventing its degradation.
What is teh basic unit of structure in compact bone?
osteon
(T/F) Bone marrow is found in compact bone.
False, its found in spongy bone.
Where are chondrocytes found?
cartilage
What is contained within the central circular region that is surrounded by the concentric rings?
blood or lymph vessels
(T/F) Fungi are eukaryotes so they have a nucleus.
True
In terms of reproduction, what is the difference between bacteria and fungi?
Bacteria reproduce asexually through binary fission while fungi can reproduce either asexually or sexually.
(T/F) Fungi absorb a varity of organism molecules as nutrients (carbon source) making them heterotrophs.
True
What is chitin found?
In the cell wall of fungi.
Where is keratin found?
in the skin of mammals;
Where is peptidoglycans found?
peptidoglycans are found in the cell wall of bacteria
Where are phospholipids found?
phospholipids are part of the cell membrane and NOT the cell wall
If there is a unit of unsaturation, is it possible for electrophilic addition to take place?
No, it would undergo nucleophilic addition.
(T/F) Aldol reaction is an example of nucleophillic addition.
True.
What kind of rxn only occurs btw unreacted carbonyl compounds and their conjugate bases (enolate ions)?
aldol condensation
Hematopoietic stem cells in the bone marrow gives rise to what cells?
- All cells found in blood including erythrocytes and platelets, which are not thsemselves whole cells but are derived from megakaryocytes.
- stem cells also give rice to B cell which produce immunoglobulins.
- platlets
Is fibrinongen derived from hematopoietic stem cells?
No, fibrinogen a clotting factor, is produced by the liver and not by blood cells.
Alkaloids
naturally occuring amines ==> look for Nitrogen.
aldehyde?

Note: this is not an alcohol
What is half of a tetraterpene? (logically speaking)
deterapene
What is ovulation induced by?
LH surge in the menstrual cycle.
If absence of LH surge, what does not occur?
ovulation.
Which part of the brain normally sends messages to respiratory muscles?
medulla;
- the respiratory control center in the medulla controls autonomic respiration without conscious involvement.
Which part of the brain is involved in coordinating motion?
cerebellum
Which part of the brain is involved in higher thought?
cerebrum
Which part of the brain is involved integration of nervous and endocrine functions through the pituitary?
hypothalamus
(T/F) Recombination occurs in both mitosis and meiosis.
False, only in meiosis
(T/F) Formation of spindle fibers, nuclear envelope breakdown, and condensation of chromosomes occurs in prophase.
True
If a specie's gender is heterogametic, what does this mean?
They must have an X and a Y. (not two of the same).
amide group
amide is either the organic functional group characterized by a carbonyl group linked to a nitrogen atom or a compound that contains this functional group, or a particular inorganic anion.
Ethanamide has how many peaks in the H NMR spectrum at RT?
3
acyl chloride (acid chloride)

note: has carbonyl group and chloride!
When an acid chloride undergoes hydrolysis, water functions in what role?
a. as an electrophile
b. as a lewis acid
c. as a catalyst
d. as a nucleophile
water nucleophilically attacks the carbonyl.
urea group

urea group is a carbonyl carbon bonded to two nitrongs.
Which one of the following molecules contains an amide linkage?
- Amide linkage is a carbonyl carbon bonded to one carbon and one nitrogen.
- Neither linolenic acid (a carboxylgic acid) nor glucose contains nitrogen.
- Ammonia contains no carbon.
- Chymotrypsin is a protein composed of amino acids all of which are bonded through amide linkages.
Hydrolysis in pure water will be slowest for which of the following compounds?
a. CH3COCl
b. CH3CH2COCl
c. CH3CH2CH2COCl
d. CH3CH2CH2CH2COCl
CH3CH2CH2CH2COCl will have the slowest rate of hydrolysis in pure water b/c it is the least soluble (due to its long hydrophobic tail) of the given choices.
Smoker's cough is due to buildup of mucus in the respiratory tract. This is the result of:
decreased ability of cilia to sweep mucus from the airway.
Tissues of the lungs, including the alveloi, are inherently (elastic/inelastic) and tend to expand (outward/collapse inward)
elastic and collapse inward
In the absence of surfactant in the alveoli, what happens?
the surface tension in the alveoli tends to draw the walls of the alveoli inward, collapsing teh alveoli as described.
What do surfactants do?
its secreted in the alveoli to reduce surface tension to prevent the alveoli from collapsing inward.
(T/F) The fetal and maternal circulatory systems don't mix contents directly.
True
What is the mechanism of gas exchange from maternal to fetal and vice versa
to diffuse across the placenta from one circulatory system to the other.
- CO2 flows down a gradient from the fetal to the materna circulation.
- Hemoglobin isn't transfered, only the gases that it carries.
- Cicarbonate ions are an important means of CO2 transport, but they aren't the molecule that is used to exchange CO2 across the membranes; this gas plays this role through PASSIVE diffusion down a gradeint
(T/F) Frameshift mutations affects translation, recombination, and transcription.
False, they only affects translation, not recombination or transcription since the enzymes carrying out these functions don't discriminate codons.
What does RNA polymerase II do?
It transcribes protein-encoding genes into mRNA (and also the snRNA genes); eukaryotes
What does RNA polymerase I do?
It transcribes the rRNA genes for the precursor of the 28S, 18S, and 5.8S molecules (and is the busiest of the RNA polymerases); eukaryotes
What does RNA polymerase III do?
It transcribes the 5S rRNA genes and all the tRNA genes; eukaryotes
Plasma contains what?
proteins and salts; it does not contain cells!
Telomeres are special DNA sequences found at the end of all linear eukaryotic chromosomes. The enzyme teomerase maintains the telomeres during DNA replication; in the absence of telomerase, the telomeres become progressively shorter with each round of ce

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