Exam 2 - Brooks

your genomic DNA is packaged into nucleosomes. What type of protein do the nucleosomes contain?

Histones

Tay Sachs is a congenital disorder in which molecules called gangliosides are not properly digested and instead accumulate in cells, causing toxicity. Misfunction in which organelle can lead to Tay Sachs?

Lysosome

a nonsense mutation is one that

creates a premature stop codon

list reasons Beadle and Tatum are wrong

quarternary structure with multiple polypeptides

what is the function of the splicing

to cleave introns from RNA and ligate the cut ends

which statement represents a notable difference between simple diffusion and facilitated diffusion?

unlike simple diffusion, the rate of facilitated diffusion is limited by the number of transport proteins in the membrane

If a double-stranded DNA sample were composed of 10 percent thymine, what would be the percentage of guanine?

40

During translation elongation, preloaded tRNA enters one of the sites of the ribosome. which site is this?

A

what is an operon

A unit of DNA containing a cluster of genes under control of a promoter and a repressor

A point mutation within what functional division of a DNA sequence would be most likely to ultimately result in the production of proteins which differ from the non-mutated form by only a single amino acid?

Exons

List the enzymes involved in DNA replication

Helicase, DNA gyrase, single strand binding protein, Primase, DNA polymerase III, DNA polymerase I, and DNA ligase

which of the following statements regarding DNA replication is true?

Prokaryotic polymerases work at a faster rate than eukaryotic ones

at what point during the cell cycle is genetic material lost from the telomeres

S phase

what constitutes the phosphodiester bonds in DNA

covalently linked nucleotides

centrioles can be found in

only eukaryotic cells

which of the following is NOT a function of the 5' terminus of mRNA

promotes polyadenylation of the 3' terminus

DNA synthesized through a process known as

semiconservative replication

which fatty acid tail would contribute most to the stability of the cell membrane of a thermophilic bacterium

(the one that is single chain and longest)

which base pairs are most prevalent at the origin of replication

A:T

An individual presenting with a mysterious disease affecting his connective tissues is found to have numerous defects in multiple regulatory proteins. if these proteins are characterized by highly abnormal patterns of glycoslyation, to what structure might the patient's disease most likely be attributed

Endoplasmic reticulum (probably should be golgi though)

our genome is primarily comprised of coding DNA (true/false)

False

DNA replication occurs during mitosis (true/false)

False (occurs during S phase before mitosis)

Malformation of which cytoskeletal structures may be linked to an inability to contract muscle?

Microfiliments Microfilaments are used for movement and contain the actin filaments used in muscle contraction.

The ciliary action of the cells lining the lumen of fallopian tubes are responsible for transporting an egg from the ovaries to the uterus. which cytoskeleton structures are linked to this movement?

Microtubules

you wish to disrupt treadmilling by treating your cell culture with a particular molecule. which molecule would you choose?

Non-hydrolyzable ATP (there are other right answers)

a non-conservative mutation is one in which

The new amino acid has different biochemical properties than the original

which statement best describes chromosomal movement during mitosis

centrioles send out microtubules, which bind to kinetochores to pull chromatids apart

If the environment surrounding a membrane-bound vesicle is hypertonic to the inside of the vesicle then water will diffuse into the vesicle, causing it to swell (true/false)

false

if the environment surrounding a membrane-bound vesicle is hypotonic to the inside of the vesicle, then water will primarily diffuse out of the vesicle, causing it to shrink (true/false)

false

during cytokinesis, a contractile ring comprised of microtubules forms the cleavage furrow (true/false)

false (it's microfilaments)

Which of the following is an advantage eukaryotes have over prokaryotes?

increased compartmentalization allowing for specialization

local conditions can affect the specificity of an enzyme for its substrate, and thus the enzymes catalytic ability. which of the following alterations would most likely not affect an enzyme in this manner

increased substrate concentration

which of the following is not involved in cell motility?

intermediate filaments

which of the following enzyme types catalyzes the formation of a phosphodiester bond between adjacent nucleotides

ligase

what is the functional relationship between codons and amino acids

many different codons may code for the same amino acid

in which phase of the cell cycle are chromosomes most condensed

metaphase (really anaphase but whatever)

The cytoskeleton of a cell can generate movements such as in cytokinesis or propulsive forces outside the cell like flagella. which structures are linked with these two movements?

microfilaments and microtubules respectively

A couple is told by their doctor that the reason why they cannot have children is that the sperm of the male lack motility because it does not have the structures responsible for propulsion. Which cellular structures are likely to be the underlying cause of this lack of motility?

microtubules

Aneuploidogens are chemicals that may disrupt gamete formation by interfering with spindle formation and the last phase of cell division. As a result the embryo may have abnormal ploidy. Based on this information, which cytoskeletal structures and which cell division process are affected by aneuploidogens?

microtubules and cytokinesis, respectively.

in sickle-cell disease, a glutamate -> valine substitution results in formation of HbS molecules, which aggregate abnormally and cannot adequately carry O2. which type of mutation results in the sicle-cell disease phenotype

missense mutation

what cellular process would you expect to immediately disrupt if you added a protein that depolymerized microtubules?

mitosis

a synonymous mutation is highly unlikely to affect a protein because

multiple codons can code for the same amino acid

you wish to disrupt dynamic instability by treating your cell culture with a particular molecule. Which molecule would you choose?

non-hydrolyzable GTP

All hydrophobic amino acids (valine, leucine, isoleucine, etc.) share which of the following properties?

nonpolar uncharged R groups

which of the following is NOT found in both prokaryotes and eukaryotes

nucleolus

what is the name of the phenomenon in which a white blood cell engulfs a pathogen? which cytoskeletal structures are involved in this process?

phagocytosis and microfilaments

during which phase does the nuclear envelope begin to disappear

prometaphase

which of the following transcriptional control features are found in both prokaryotes and eukaryotes?

promoter repressors

Hydrogen bonding between separate subunits of DNA polymerase is an example of which of the following

quaternary structure

which cellular function may be disrupted because of a malformation of the intermediate filaments

resilience to compression forces

the alpha helix is an example of which of the following structural properties of proteins?

secondary structure

In eukaryotes, the chromosome ends shorten during somatic cell division. these regions at the chromosome termini are known as

telomeres

which of the following statements about the 5' end of a polynucleotide strand of RNA is correct

the 5' end has a phosphate group attached to the number 5 carbon of ribose

enzymes catalyze biochemical reactions by altering which of the following quantities associated with reaction

the activation energy Ea

where within the eukaryotic cell might a drug which exclusively binds to tRNA binding sites exert its effects

the cytosol

Dynamic instability refers to

the rapid polymerization and depolymerization of microtubules

Cholera affects millions of people around the world. It causes diarrhea, which can lead to dehydration and even death. Cholera toxin affects a chloride transporter that secretes chloride ion into the lumen of the small intestine. How does cholera toxin lead to dehydration?

the toxin turns on the transporter, and water follows the ion due to osmosis

in genomic DNA, the number of purines is always the same as the number of pyrimidines (true/false)

true