cell bio oe mc
which of the following can separate proteins based on their mass?
A and C SDS polyacrylamide electrophoresis and ultracentrifugation
which of these blood types is the universal recipient?
AB
what type of protein is the cystic fibrosis transporter (CFTR)?
ABC transporter
what type of transporter is the sodium/potassium pump?
ABC transporter
which of these plays a role in the degradation of proteins?
B and C ubitquitin & proteasome
which of these systems is used to create genetic knockouts in mice?
Cre/Lox
which enzyme is most involved in DNA replication?
DNAP III
the 3D structure of a protein can be determined using
X ray crystallography
what structural motif is often found in the DNA-binding part of the activator proteins?
Zinc finger
what cell structure did flemming describe?
a chromosome
binding of oxygen to hemoglobin is an example of:
allosteric binding
what proces in important for producing sex determination proteins in drosophila?
alternative splicing
which of these is best genetic model system to study plant diseases?
arabidopsis thaliana
what process most directly contributes to microsatellite formation?
backward slippage
the one gene = one enzyme concept was formulated by
beadle and tatum
histones pack DNA into a structure referred to as
beads on a string
what type of protein structure is most associated with bacterial porins?
beta barrel
what units are used when frequency of recombination events are applied to map gene positions?
centimorgans
which of these is the most common genetic disease in caucasian populations?
cystic fibrosis
where does glycolysis occur in a eukaryote?
cytoplasm
which these would have the smallest diameter?
ds-DNA
due to steric inhibition in the substrate binding site, which of these serine proteases cuts by small amino acids?
elastase
which is true of enzymes?
enzymes lower the activation energy of a reaction
highly acetylated histones are associated with what?
epigenetic regulation
ultracentrifuges allow cell biologists to separate mitochondria from lysosomes based upon their:
equilibrium density
which of these sterols is most associated with fungi?
ergosterol
what are the coding portions of a mRNA called
exons
what is the fate of introns after splicing?
exosome degradation
what type of transport is exemplified by the GLUT glucose transporter?
facilitated diffusion
which of these is the msot powerful source of energy in a cell?
flow of electrons
what type of molecules can be transported by simple diffusion?
gasses
protein size is used to separate proteins in
gel filtration chromatography
medel's hereditary factors are now referred to as
genes
which of these amino acids is most important for forming a beta turn in a protein structure?
glycine
due to the elctronegativity of oxygen, water molecules:
have a dipole moment
_____ DNA is more highly condensed in the nucleus of cells
heterochromatic
where is the branch point for RNA splicing located?
in an intron
what is the function of the HIV tat protein?
inhances transcription of viral genes
which of these is not a step necessary to generate a monoclonal antibody?
inject the mouse with antibodies that bind to the target molecule
what typically flanks the structure of an IS element?
inverted repeats
the _____ point is the pH were a protein has no net charge
isoelectric
what effect does a high ATP level have on phosphofructokinase activity?
it decreases it
a phospholipid sphere that contains an internal aqueous chamber is called what?
liposome
what is the most common means of regulating gene expression in a cell?
mRNA transcription
what is the function of telomerase in a cell?
maintain the ends of chromosomes
what is the main function of RNAP III?
making tRNA and small RNA
which of these molecules inhibits translation?
miRNA
very thin slices of tissue can prepared using a
microtome
what is the "powerhouse" of cell?
mitochondria
which of these is the best genetic model system to study human diseases?
muscus domesticus
if a cellular homogenate was subjected to differential centrifugation, what would pellet first?
nuclei
where are pre-rRNA produced
nucleolus
heterochromatic DNA is more highly condensed in the ___ of cells
nucleus
which of these would sediment fastest in an ultracentrifuge?
nucleus
which of the paths for inner mitochondrial membrane protein insertion does not require a matrix targeting sequence?
pathway C
who showed the urea can be produced artificially?
wohler
which of the following organisms likely has the highest density of protein coding regions in its chromosome?
yeast
where would you find a cap during eukaryotic transcription?
5' end of mRNA
which of these is found in a deoxyribonucleotide but not in a ribonucleotide?
1' thymine
how many carbons are added to fatty acid in each cycle extension during biosynthesis?
2
what percent of the human genome codes for structural proteins?
2%
in the sodium/potassium transported:
3 sodium leave the cell and 2 potassium enter the cell
how many total ATP are formed in glycolysis?
4 ATP
which of these technique can be used to rapidly sort cells using fluorescent tags?
FACS
_____ was the first to see and coin the word "cells"
Hooke
what term refers to the concentration of substrate that gives 1/2 maximal transport activity?
Km
the signal sequence for ER proteins in found where?
N-terminal end
what is the main function of snRNA in a cell?
RNA splicing
which RNA polymerase is most resistant to amantadin?
RNAPI
which protein is most important for cycling importins and exportins into and out of the nucleus?
Ran
which of the following would not contain reverse transcriptase?
SINE
highly transcribed genes in eukaryotes usually contain what kind of elements?
TATA boxes
What type of ER transport results in a cytosolic carboxyl domain on the inserted protein?
Types I and III
what unit of measure is most often used in cell biology?
Um
which of these is most associated with acidification of endosomes in a cell?
V pump
unfolded proteins in a cell can form
plaque, which can lead to disease
how do phospholipids interact with water molecules?
polar heads interact with water; non-polar tails do not interact with water
what process is used in the lab to make copies of a dna sequence?
polymerase chain reaction
what process is GroEL/GroES involved with in escherichia coli?
protein folding
which of these is commonly a ribozyme?
rRNA
which type of mutant only exhibitsa phenotupe in a homozygous individual?
recessive
what is used to create "sticky ends" on DNA to facilitate molecular cloning?
restriction endonuclease
what enzyme do retroviruses use that our cells normally do not?
reverse transcriptase
a _____ microscrope can be used to see a 3D image outside of a viral particle
scanning electron
which of these scientists postulated the cell theory?
schwann
an alpha helix is an example of protein:
secondary structure
which of the following would have the highest levels of fluidity (most oil-like)?
short chain unsaturated fats
what is the function of aquaporins?
shuttle water across the membrane
what is the most common genetic disease of the african american population?
sickle cell anemia
what type of transport does not require a protein carrier?
simple diffusion
where does most cholesterol synthesis occur in a cell?
smooth ER
where would you find an anticodon in a cell?
tRNA
what are the ends of chromosomes called?
telomeres
which fo these dow not impose limits on protein folding in a cell?
the backbone sequence of the polypeptide
what factor most affects the resolving power of light microscopes?
the wavelength of visible light
the best 3-D images of cellular organelles come from:
thin section electron microscopy
the study of all mRNA produced in a cell is called what?
transcriptomics
mobile DNA elements can excise and move to new locations via the action of
transposase
what type of ER transport results in the insertion of a multi-helix protein in the membrane?
type IV
which of the following modifications marks proteins for destruction by the proteasome?
ubiquitination