exam two Flashcards by Paige Renschler

Long noncoding RNA (IncRNA) can function as a(n)
protein scaffold
RNA polymerase
transcriptional regulator
telomerase

protein scaffold

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Which protein complex mediates the RNAi silencing process by inhibiting RNA polymerase via histone methylation and heterochromatin formation?
mediator
RITS
RISC
RNase

RITS

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MicroRNAs block the expression of a specific gene product by binding to the _____ and inhibiting ______.
mRNA; translation
DNA; transcription
protein; activity
ribosome; translation

mRNA; translation

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The control of a gene product’s levels or activity after transcription has taken place is called
post-transcriptional control
cell memory
combinatorial control
epigenetic inheritance

post-transcriptional control

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The figure below depicts which of the following mechanisms that cells use to maintain their identity through cell divisions?
positive feedback
DNA methylation
histone modification
differentiation

positive feedback

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A transcriptional regulator that activates expression of additional transcriptional regulators that induce production of a particular cell type or organ is called a
master regulator
reprogramming regulator
feedback activator
terminal differentiator

master regulator

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In eukaryotes, multiple genes can be expressed simultaneously by
the arrangement of multiple genes into an operon
the binding of a specific transcriptional regulator to several genes
the binding of a mediator complex to several genes at once
a repressor protein binding to multiple operators

the binding of a specific transcriptional regulator to several genes

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In the cell, enhancer sequence functions are limited in their range of action by the formation of _______ that hold specific genes and enhancers in close proximity.
loops
chromatin
helics
operons

loops

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Eukaryotic repressor proteins can decrease transcription using which of the following mechanisms?
binding an operon and preventing polymerase binding
recruiting a histone acetyltrasferase complex to modify histones
preventing the assembly of the transcription initiation complex
attracting a chromatin remodeling complex to open chromatin at the site

preventing the assembly of the transcription initiation complex

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Excess amounts of the amino acid tryptophan result in down regulation of the expression of the enzymes required for its synthesis due to ______
the repressor binding to the operator
inactivation of the repressor protein
the inability of the repressor to bind to the operator
the inactivation of RNA polymerase

the repressor binding to the operator

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Which of the following is the main point of control for regulating gene expression levels?
translation
transcription
protein degradation
mRNA degradation

transcription

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A housekeeping gene is a gene whose cellular function is
involved in removal of waste product from cells
turned off periodically for maintenance
important for processes found in all cell types
critical for specialized activities in a specific cell type

important for processes found in all cell types

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Transplanting the nucleus of an epithelial cell into an egg cell lacking genetic information leads to the formation of
another epithelial cell
a dead cell
a normally developing embryo
a hybrid cell that has characteristics of both embryonic cells and epithelial cells

a normally developing embryo

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The following image shows two triacylglycerol molecules with different fatty acid chains. If these fatty acids were in a phospholipid molecule, which of the two would form the most fluid membrane?
saturated
unsaturated
both would form very fluid membranes
both would form very stiff membranes

unsaturated

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______ of ATP creates an irreversible step of a motor protein to move it in one direction
oxidation
hydrolysis
reduction
dehydration

hydrolysis

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Arrange the cellular respiration events in order
glycolysis
citric acid cycle
electron transport chain
digestion

digestion
glycolysis
citric acid cycle
electron transport chain

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Where does glycolysis take place?
cytosol
endoplasmic reticulum
mitochondrial inter-membrane space
mitochondrial matrix

cytosol

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which of the following requires energy?
simple diffusion
osmosis
active transport
passive transport

active transport

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catabolic metabolism pathways (select all that apply)
require energy
add chemical bonds
produce heat
remove chemical bonds

produce heat
remove chemical bonds

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which of the following are considered energy carriers? (select all that apply)
H2O
O2
ATP
FADH2

ATP AND FADH2

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Which of these are produced in the citric acid cycle (select all that apply)
NADH
GTP
Pyruvate
FADH2

NADH
GTP
FADH2

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The following occur during the electron transport chain (select all that apply)
acetyl CoA is combined with oxaloacetate to form citrate
carbon atoms are stripped of fatty acid chains
high energy electrons are transferred through protein complexes in the inner mitochondrial matrix
protons are pumped into the mitochondrial intermembrane space

high energy electrons are transferred through protein complexes in the inner mitochondrial membrane
protons are pumped into the mitochondrial intermembrane space

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which of the following are sub-units of ATP synthase (select all that apply)
heavy chain
stationary head (F1)
rotating ring (F0)
light chain

stationary head (F1)
rotating ring (F0)

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

DNA and ribosomes

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Which of the following molecules require transporters to enter a cell (select all that apply) O2 CO2 glucose H+

glucose H+

What 4C compound is used in the Citric Acid Cycle? NADH acetyl CoA Glucose Pyruvate

acetyl CoA

which of the following are ways that an enzyme catalyzes reactions (select all that apply) acting over large distances aligning substrates rearranging chemical bonds rearranging charges in a substrate

aligning substrates rearranging chemical bonds rearranging charges in a substrate

scramblases are enzymes that _______ catalyze transfer of specific phospholipids to the cytosolic monolayer in the Golgi catalyze transfer of specific phospholipids to the cytosolic monolayer in the ER catalyze random transfer of phospholipid monolayers in the ER catalyze random transfer of phospholipid monolayers in the Golgi

catalyze random transfer of phospholipid monolayers in the ER

Foods are broken down into simple molecular subunits for distribution and use throughout the body. Which type of simple subunits, listed below, is used preferentially as an energy source? simple sugars proteins glycerol free fatty acids

simple sugars

The final metabolite produced by glycolysis is glutamate acetyl CoA 3-phosphoglycerate pyruvate

pyruvate

Which of the following is NOT a way that cells restrict the lateral movement of membrane proteins? anchoring to internal cell components like actin or other proteins tethering to external cell components like the extracellular matrix or adjacent cells establishing diffusion barriers in the membrane reducing the temperature of the membrane

reducing the temperature of the membrane

In a FRAP experiment, a fluorescently tagged membrane protein, A, shows very little recovery of fluorescence ten minutes after photobleaching, while membrane protein B shows a rapid increase in fluorescence after bleaching, recovering nearly 80% of its original fluorescent signal by ten minutes. Based on this information, which of the following statements can be made? Protein A has faster mobility in the membrane Protein B is diffusing in a more fluid membrane Proteins A and B interact with each other in a complex Protein A is easily denatured

Protein B is diffusing in a more fluid membrane

In a famous experiment, mouse cells and human cells were fused into hybrid cells and the membrane proteins of human origin and mouse origin were specifically tagged and examined. After cell fusion and incubation, what was observed by investigators? the mouse and human proteins remained separated from each other on opposite sides of the hybrid cell The mouse proteins mixed throughout the membrane of the hybrid cell, whereas the human proteins remained in half of the membrane, in their original location the human proteins mixed throughout the membrane of the hybrid cell, whereas the mouse proteins remained in half of the membrane, in their original location the mouse and human proteins mixed evenly throughout the membrane of the hybrid cell

the mouse and human proteins mixed evenly throughout the membrane of the hybrid cell

detergent molecules are _______ in nature and bind with membrane proteins and membrane lipids to disrupt their interactions and release the proteins from the membrane amphipathic hydrophobic hydrophilic polar

amphipathic

Which of the following is a common transmembrane protein structure that can traverse the membrane to form a pore or channel by alternating hydrophobic and hydrophilic amino acids? single-pass alpha helix multipass alpha helix beta barrel beta sheet

beta barrel

If the backbone of a polypeptide is hydrophilic, how can a transmembrane alpha helix span the hydrophobic portion of the lipid bilayer? because amino acid side chains in a transmembrane helix are hydrophobic and interact with the hydrophobic interior of the bilayer because the membrane bends in such a way that the polar heads of the lipids contact the transmembrane helix because the hydrophilic backbone makes a hole in the membrane because many transmembrane alpha helices must come together in a way that neutralizes the hydrophilic backbone

because amino acid side chains in a transmembrane helix are hydrophobic and interact with the hydrophobic interior of the bilayer

Proteins that are associate with the membrane by non-covalent interactions with other membrane proteins are called ______ proteins integral membrane peripheral membrane monolayer-associated lipid-linked

peripheral membrane

How is the protein shown in the diagram associated with the plasma membrane? it is associated with one layer of the lipid bilayer it is a membrane-spanning protein (transmembrane) it is linked to lipids in the bilayer it is attached to another protein that is a transmembrane protein

it is associated with one layer of the lipid bilayer

plasma membrane proteins that move ions in and out of cells using active transport are called transporters channels anchors receptors

transporters

______ are the most abundant molecules in the animal cell membrane, whereas ______ make up 50% of the membrane by mass lipids, proteins proteins, lipids lipids, carbohydrates carbohydrates, lipids

lipids, proteins

If a phospholipid is located in the outer layer of the bilayer in a vesicle, where will it end up when the vesicle fuses with the plasma membrane? the cytosolic face of the bilayer the extracellular face of the bilayer randomly on one side or another vesicles cannot fuse with the plasma membrane

the cytosolic face of the bilayer

a phospholipid is inserted into the cytosolic side of the ER membrane. Which of the following could randomly reposition this phospholipid to the other (lumen) side of the ER membrane? flippase scramblase glycolipids golgi apparatus

scramblase

where are new phospholipids made? endoplasmic reticulum golgi apparatus mitochondria nucleus

endoplasmic reticulum

why do cells regulate their membrane fluidity? so they don't freeze in cold temperatures to allow membrane proteins to diffuse to where they are needed for their function so that large, charged molecules can easily pass through the membrane to keep two neighboring cells from easily fusing

to allow membrane proteins to diffuse to where they are needed for their function

a less permeable membrane is likely to have more cholesterol less cholesterol many unsaturated fatty acids shorter fatty acid tails

more cholesterol

a cell membrane made up primarily of lipids with which characteristics would be the least fluid? short, unsaturated fatty acid tails long, saturated fatty acids tails long, unsaturated fatty acid tails short, saturated fatty acid tails

long, saturated fatty acid tails

which type of movement is the least common for lipids in a bilayer? flip-flop lateral diffusion flexion rotation

flip-flop

What kind of lipid molecule is represented in this figure? phospholipid glycolipid cholesterol triacylglycerol

phospholipid

phospholipids assemble into a membrane using enzymes hydrophobic forces assembly proteins covalent bonds

hydrophobic forces

Which of the following is not commonly found in the plasma membrane? carbohydrates proteins nucleic acids fatty acids

nucleic acids

a transcriptional regulator that activates expression of additional transcriptional regulators that induce production of a particular cell type or organ is called a master regulator reprogramming regulator feedback activator terminal differentiator

master regulator

A reporter gene is an experimentally engineered regulatory DNA sequence from a gene of interest that has been fused to a gene that encodes a protein that is easily observed experimentally. Why is this approach useful? it can provide information as to where a gene is expressed it can provide information as to when a gene is expressed it provides information into where and when a gene is expressed it provides information on the binding interactions of the gene product

it provides information into where and when a gene is expressed

In eukaryotes, multiple genes can be expressed simultaneously by the arrangement of multiple genes into an operon the binding of a specific transcriptional regulator to several genes the binding of a mediator complex to several genes at once a repressor protein binding to multiple operators

the binding of a specific transcriptional regulator to several genes

many transcriptional regulators function together to decide the expression level of a particular gene. this describes the concept of operons repression combinatorial control activation

combinatorial control

Which of the following mechanisms describes how eukaryotic activator proteins can regulate chromatin packaging to enhance transcription? binding to enhancer regions to promote formation of the transcription initiation complex activating polymerase binding through contacts made in the activation region recruiting histone deacetylase complexes to remove acetyl groups from histones recruiting chromatin-remodeling complexes to eject or slide nearby nucleosomes

recruiting chromatin-remodeling complexes to eject or slide nearby nucleosomes

Generally, bacterial promoters that are regulated by transcriptional activators bind _______ to RNA polymerase on their own, but promoters that are regulated with transcriptional repressors bind ________ to RNA polymerase weakly; strongly strongly; weakly weakly; weakly strongly; strongly

weakly; strongly

Mutations in which of the following elements would abrogate RNA polymerase's ability to activate gene expression? regulatory DNA sequence region promoter transcription termination site major groove

promoter

Which enzyme class is involved with randomly distributing phospholipids in the membrane? ion channels ATPases Scramblases Flippases

Scramblasaes

Which class of enzyme is involved with transfer of phospholipids to create asymmetric distribution in a membrane? Flippases ATPases Lipases Scramblases

Flippases

Which of these are functions of membrane associated proteins? (select all that apply) anchoring to the extracellular matrix ion transport across a membrane transcription translation

anchoring to the extracellular matrix ion transport across a membrane

what method do protozoans use to prevent osmotic swelling? contractile vacuoles cell wall ion transport none of these

contractile vacuoles

Which of the following contribute to the net driving force needed to move a solute across a membrane (select all that apply) the membrane potential the solute concentration the charge of the solute the electrochemical gradient

all of the above

Which of the following are areas where gene expression can be regulated? (select all that apply) transcriptional control at gene locus mRNA transport and localization translational control RNA processing

all of the above

Which of the regulatory RNA protein complex is involved in the cells' protection from viral or bacterial DNA lnRNA RITS miRNA DICER siRNA RITS miRNA RITS

siRNA RITS

Which of the following would be considered reporter genes? (select all that apply) LacZ GFP RFP mCherry

all of the above

Transporters, in contrast to channels, work by filtering solutes by size filtering solutes by charge a gating mechanism specific recognition of transport substrates

specific recognition of transport substrates

The figure below illustrates charges in membrane potential in the axon of a neuron. What membrane characteristic or measurement is indicated by the arrow? threshold potential resting membrane potential action potential stimulation potential

action potential

What gives rise to a membrane potential the distribution of ions across the membrane electrical charges from the environment the distribution of uncharged molecules across the membrane the amount of glucose in a cell

the distribution of ions across the membrane

aquaporins are channels that primarily allow passage of _____ through bilipid membranes water electrons ions protons

water

What is the byproduct of aerobic respiration in yeast? methanol and O2 ethanol and O2 methanol and CO2 ethanol and CO2

ethanol and CO2

what is the final byproduct of aerobic glycolysis pyruvate FADH2 Citrate lactate

pyruvate

exam two Flashcards

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