practice quiz Flashcards by Paige Renschler

The technique that scientists used to determine that hemoglobin was a single large macromolecule rather than a loose conglomeration of small organic molecules was
electron microscopy.
ultracentrifugation.
DNA sequencing.
hydrolysis.

ultracentrifugation

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In a polypeptide chain, what determines the shape of a protein

amino terminus
peptide bonds
carboxyl terminus
side chains

side chains

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____ is an example of a structural protein
Transducin
Sodium ATPase
Collagen
Aquaporin

collagen

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What types of bonds and/or forces help proteins fold? Choose all that apply.
electrostatic attractions
van der Waals attractions
hydrogen bonds
covalent bonds

electrostatic attractions
van der Waals attractions
hydrogen bonds

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A prion disease is a contagious nervous system disease caused by
viral RNA
misfolded proteins
E coli bacteria
Cytomegalo viruses (CMV)

misfolded proteins

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What generally stabilizes extracellular proteins?
electrostatic attractions
hydrogen bonds
covalent bonds
van der Waal’s attractions

covalent bonds

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what is the function of an antibody?
to transport water into a cell
to bind antigens of foreign entities in many animals
to bind foreign DNA
to bind foreign RNA

to bind antigens of foreign entities in many animals

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what experimental information can you get from an SDS-page gel? (select all that apply)
protein size
DNA size
estimated protein concentration
estimated RNA concentration

protein size
estimated protein concentration

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Which of the following are known protein domains? (select all that apply)
nuclease
activator
homeodomains
repressor

all of the above

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Which of the following are domains of an antibody? (select all that apply)
nuclease domain
variable heavy chain
homeodomain
variable light chain

variable heavy chain
variable light chain

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Mitochondria and chloroplasts are thought to have arisen from bacterial ancestors because they still possess which of the following features?
a nucleus
DNA and ribosomes
lysosomes
endoplasmic reticulum

DNA and ribosomes

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Which of the following are benefits of using C. elegans (worms)? (select all that apply)
cheap
can be stored in a freezer
very fast
immune system can be humanized

cheap
can be stored in a freezer
very fast

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Which of the following are found in plant and not animal cells? (select all that apply)
endosomes
vacuoles
peroxisomes
chloroplasts

vacuoles
chloroplasts

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what is used to transport molecules around the cell? (select all that apply)
microtubules
vesicles
intermediate filaments
actin filaments

microtubules
vesicles
actin filaments

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Which organelles are involved in intracellular sorting? (select all that apply)
golgi
endosome
lysosome
mitochondria

golgi
endosome

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In the absence of light where do some bacteria get their energy from?
oxidizing H2C
oxidizing H2S
oxidizing H2O
oxidizing H2N

oxidizing H2S

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Where did mitochondria come from in evolution?
an ancestral eukaryote
an ancestral fungi
an ancestral prokaryote
an ancestral archae

an ancestral prokaryote

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What forms the rigid structures at the core of most proteins?
heavy chains
nuclease domains
alpha helices
beta sheets

beta sheets

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A multi-pass transmembrane region of a protein… (select all that apply)
is made up of multiple alpha helical domains
is made up of multiple beta sheets
pass through the membrane because of their exposed hydrophobic side chains
is only found in the nuclear envelope

is made up of multiple alpha helical domains
pass through the membrane because of their exposed hydrophobic side chains

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How do alpha helix structures form in proteins?
The H-N-H2 of every peptide bond is hydrogen bonded to the O=H of a neighbouring peptide 6 amino acids away
The N-N of every peptide bond is hydrogen bonded to the O=O of a neighbouring peptide 4 amino acids away
The C=O of every peptide bond is hydrogen bonded to the O-H of a neighbouring peptide 6 amino acids away
The N-H of every peptide bond is hydrogen bonded to the C=O of a neighbouring peptide 4 amino acids away

The N-H of every peptide bond is hydrogen bonded to the C=O of a neighboring peptide 4 amino acids away

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What is phosphorylation of a protein generally associated with?
its activity
its size
its translation
its cytologic location

its activity

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allosteric enzymes have_____ (select all that apply)
only one binding site
two or more binding sites
binding sites that influence each other
no binding sites

two or more binding sites
binding sites that influence each other

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What is required for motor proteins to move?
NADPH hydrolysis
NAD hydrolysis
ATP hydrolysis
DTP hydrolysis

ATP hydrolysis

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Which of the following are protein domains in an antibody? (select all that apply)
Variable Y chain
Variable X chain
Variable heavy chain
Variable light chain

Variable heavy chain
Variable light chain

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Which of the following are functional classes of enzymes? (select all that apply) hydrolase nuclease protease triptynase

hydrolase nuclease protease

What signals translation to a halt? a stop codon a start codon the 3' poly A tail the 5' cap

a stop codon

during translation a tRNA carrying the next amino acid binds to the A site T site P site E site

A site

Which of the following are responsible for coupling tRNAs with their amino acids? nitryl-tRNA synthases aminoacyl-tRNA synthases hydroxyl-tRNA synthases carboxyl-tRNA synthases

aminoacyl-tRNA synthases

A segment of DNA in the genome that is not a protein-coding gene ______ is junk DNA left over from mistakes in evolution is completely unimportant to the cell can be used to regulate gene activity must encode a functional RNA

can be used to regulate gene activity

If a gene sequence in one organism is highly similar to the sequence of another gene in another organism it is called homologous related protein coding comparitive

homologous

The fruit fly is an excellent model for studying fundamentals of development because the precise formation of each of their 959 body cells has been mapped they are transparent and allow visualization of cell division and movement they reproduce every 30 minutes on a plate many of the genes involved in the development of the fruit fly are also found in humans

many of the genes involved in the development of the fruit fly are also found in humans

The rules of which fundamental process were elucidated in the bacterim E. coli? DNA replication cell division cycle mitosis embryonic development

DNA replication

Which of the following is a role of the cytoskeleton in plant cells? Intermediate filaments support chloroplast structure Actin filaments guide cell movement Microtubules form tracks for movement of cell components Intermediate filaments form strong links to the plant cell wall

Microtubules form tracks for movement of cell components

The cell components that move materials from one organelle to another are called transport vesicles endoplasmic reticulum golgi apparatus cytosol

transport vesicles

Lysosomes and peroxisomes both perform a series of reactions to break down molecules, but one difference between them is that peroxisomes contain hydrogen peroxide lysosomes break down toxic molecules peroxisomes digest molecules for reuse lysosomes are large and form an interconnected network

peroxisomes contain hydrogen peroxide

Archaea and bacteria are two separate domains of prokaryotes that were distinguished by examining their cell structures their DNA sequences the presence vs. absence of a nucleus the presence vs. absence of chloroplasts

their DNA sequences

which of the following microscopy techniques allows the observation of living cells scanning electron microscopy fluorescence microscopy transmission electron microscopy there are no microscopy techniques suitable for the observation of living cells

fluorescence microscopy

Which of the following microscopy techniques would allow the most detailed image showing the 3-D structure of a flagellum? scanning electron microscopy transmission electron microscopy high-resolution fluorescence light microscopy conventional light microscopy

scanning electron microscopy

the genes in the genome of an adult organism must all be expressed in all cells of the organism for survival are mostly silenced after embryonic development is complete are expressed or silenced depending on whether a gene is needed in that cell type and environment are vastly different in composition depending on the cell type

are expressed or silenced depending on whether a gene is needed in that cell type and environment

self-replication of living cells occurs through the catalytic action of DNA RNA proteins nucleotides

proteins

DNA is a better molecule for long-term storage of genetic information than RNA because the deoxyribose sugar stabilizes DNA chains the uracil in DNA is less easily mutated DNA is able to make complex folded secondary structures DNA is able to autocatalyze its own repair

the deoxyribose sugar stabilizes DNA chains

Which of the following properties could help RNA be both an information storage unit and a self-replicating molecule? RNA can act as a template for making copies of itself RNA is a short-lived molecule RNA cannot catalyze reactions RNA must be made from DNA

RNA can act as a template for making copies of itself

Protein concentration can be regulated by all of the steps listed EXCEPT nuclear export RNA processing mRNA stability DNA replication

DNA replication

What is the name of the complex that degrades proteins that have reached the end of their lifespan, are damaged, or are misfolded? proteasome nuclease ribosome nuclear pore complex

proteasome

What recognizes the stop codons in an mRNA? release factor a specialized tRNA linked to methionine nothing the 3' poly-A tail

release factor

the catalytic sites for peptide bond formation during translation is found in which part of the ribosome? large subunit RNAs large subunit proteins small subunit RNAs small subunit proteins

large subunit RNAs

How do tRNAs become attached to the correct amino acid? aminoacyl-tRNA synthetases RNA polymerases rRNA ribozymes translation initiation factors

aminoacyl-tRNA synthetases

The splicing of introns out of an mRNA molecule is catalyzed by RNA molecules that base pair with the splice sites to promote intron removal proteins that contain metal ions to pull electrons from the phosphate bonds RNA molecules that act as a template for new RNA synthesis using exons only proteins that act as nucleases to chew away and remove the introns

RNA molecules that base pair with the splice sites to promote intron removal

What performs the function of bacterial sigma factor in eukaryotes? general transcription factors initiation proteins nucleosomes promoters

general transcription factors

Which type of RNA is converted into protein for performing its cellular function? tRNA rRNA mRNA miRNA

mRNA

At which step of gene expression can cells amplify the number of copies of a protein made from a single gene? transcription translation neither transcription nor translation both transcription and translation

both transcription and translation

The process of gene expression always involves which process(es) described in the central dogma? transcription translation replication transcription and translation

transcription

What is a protein family? a set of proteins that have the same number of domains a group of proteins from unrelated species a structurally related group of proteins a collection of proteins that have all been crystallized

a structurally related group of proteins

Which method is most suitable for determining the three dimensional structure of an extremely large integral membrane protein complex? NMR spectrosccopy mass spectrometry x-ray crystallography cryoelectron microscopy

cryoelectron microscopy

Which method is used for separating proteins based on specific interactions with other molecules? mass spectrometry gel electrophoresis affinity chromatography x-ray crystallography

affinity chromatography

Chemical modifications like phosphorylation and acetylation of proteins occur on _____ of amino acids and can affect interaction of proteins with other cell components or structures amino groups carboxyl groups side chains peptide groups

side chains

How does phosphorylation of a protein affect its activity? always increases activity always decreases activity never affects activity could increase or decrease activity

could increase or decrease activity

When a ligand binds to an allosteric enzyme's regulatory site, it changes the activity of that enzyme by directly blocking the active site inducing a conformational change acting as a chaperone denaturing the enzyme

inducing a conformational change

disulfide bonds stabilize protein shape outside the cell by covalent bonds between cysteines noncovalent bonds between charged side chains hydrophobic interactions within the lipid bilayer hydrogen bonds with water molecules

covalent bonds between cysteines

a binding site on the surface of a protein interacts specifically with another protein through many weak noncovalent interactions a few strong noncovalent interactions many weak covalent interactions a few strong covalent interactions

many weak noncovalent interactions

which of the following shows protein organizational units in the correct order from smallest to largest? subunit

domain

a stretch of amino acids in a polypeptide chain that is capable of independently folding into a defined structural unit is called a domain backbone subunit ligand

domain

which of the following is true about amyloid protein structures? they always cause neurodegenerative diseases they are weak and brittle they consist of stacked beta sheets they are made up of helical protein fibers

they consist of stacked beta sheets

which type of noncovalent interaction can involve either the polypeptide backbone or amino acid side chains? van der Waals attractions hydrophobic forces hydrogen bonds electrostatic interactions

hydrogen bonds

In what part of the cell are proteins destroyed? mitochondria endoplasmic reticulum golgi apparatus lysosome

lysosome

Which of the following are model organisms (select all that apply) mouse fruit fly ecoli hippo cat

mouse fruit fly ecoli

Which of the following are components of the cytoskeletal network? microtubules mitochondria lysosomes endosomes

microtubules

What is the primary function of the inner membrane space of the mitochondria? proton movement during the electron transport chain to isolate the mitochondria from the cytoplasm store the nuclear material generate plasma membranes

proton movement during the electron transport chain

What determines the shape of a protein? the covalent bonds between side chains amino acid side chains and their sequence the distribution of amino and carboxyl groups in a polypeptide chain the structure of DNA and RNA molecules

amino acid side chains and their sequence

Which of the following are general functions of proteins? (select all that apply) catalyze reactions transcription signaling storage

all of the above

Out of the 20 amino acids which of the following are characteristics of side chains? (select all that apply) carboxyl groups amino groups positively charged negatively charged

positively charged negatively charged

What determines the directionality of a protein? the orientation of the carboxyl and amino groups hydrogen bonds the orientation of the side chains the orientation of hydrogen bonds

the orientation of the carboxyl and amino groups

correct protein folding occurs through (select all that apply) covalent bonding between positively charged side chains chaperon proteins guiding energetically favorable conformations hydrophobic forces and lowest energy conformation positioning of ribosomes along the endoplasmic reticulum

chaperon proteins guiding energetically favorable conformations hydrophobic forces and lowest energy confromation

disease-causing misfolded proteins are called crystals E. coli prions sponges

prions

Which of the following are considered levels of organization of a protein (select all that apply) domains alpha helices secondary structure covalent bonds subunits

domains alpha helices secondary structure subunits

what types of bonds help to stabilize extracellular proteins? Van Der Waals Covalent electrostatic hydrogen

covalent

which of the following is true for a molecule that binds a protein (select all that apply) the protein domain where binding occurs is known as a binding site binding is highly selective the molecule would interact with a ligand it occurs through noncovalent bonds between amino acids side chains and the molecule

the protein domain where binding occurs is known as a binding site binding is highly selective it occurs through noncovalent bonds between amino acid side chains and the molecule

Which polymerase transcribes mRNA? PolII PolI PolIII PolIV

PolII

During transcription initiation which general transcription factor complex binds to the TATA TFID TFIIB TFIE TFIH

TFID

Which processes occur simultaneously during mRNA transcription? (select all that apply) capping splicing polyadenylation translation

capping splicing polyadenylation

in what part of the nucleus does mRNA transcription take place euchromatin heterochromatin nucleolus chromosomes

euchromatin