Cell Bio final review

____ terminates a signal by rapidly converting cyclic AMP to ordinary AMP.

Cyclic AMP phosphodiesterase

What serves to protect proteins from pH changes and digestive enzymes?

Disulfide bonds

Cell surface receptors alter the function of ____

Effector proteins

The ____ pathway moves materials from the plasma membrane, through endosomes, to lysosomes.

Endocytic

GTPases___

Exchange GTP for GDP

Why would a red blood cell plasma membrane need transmembrane proteins?

For structural support and ion exchange

What ion balances the negative charge within a cell?

K+

What enzyme creates sugars during carbon fixation?

Rubisco

What directs a protein to its destination organelle?

Sorting siganl

Glycogen serves what purpose?

Storage

What does the constuitive exocytosis pathway do besides expel intracellular materials?

Supplies the plasma membrane with newly made lipids and proteins

An exported mRNA containing 300 nucleotides can initially be translated into a protein that is approximately how many amino acid residues in length?

100 amino acid residues

Which of the following sequences are usually located within eukaryotic promoters 25 base-pairs away from the transcription start site and has a role in forming the transcription pre- initiation complex?

5'-TATA-3'

What is the major difference between a phospholipid molecule and a detergent molecule?

A detergent only has one hydrophobic tail and a phospholipid has two

What is ion selectivity?

A function that allows only some inorganic ions to pass through the plasma membrane but not others

Equation for cellular respiration

C6H12O6 (glucose) + 6O2 (oxygen) ---------> 6CO2 (carbon dioxide) + 6H2O (water) + energy

What coverts an electrical signal to a chemical signal?

Ca2+

What ion is involved in synaptic plasticity?

Ca2+

The plasma membrane of animals cells is stabilized by a meshwork of fibrous proteins, called the ______

Cell cortex

What are most vesicle coats made out of?

Clatherin

Which of the below underlined codons will be selected as the translation initiator codon? 5'...AUAUAUGGAGGCGGCAACGCGCACAUGGCGCGCAAUGAGGGCCGCCACCAUGACCGGC...3' 1 2 3 4

Codon 1

Which is not a type of cell signaling?

Contact-independent signaling

On their way to the lysosome, endocytosed materials must first pass through a series of compartments called ____, which sort the ingested molecules and recycle some back into the plasma membrane

Endosomes

The Nernst Equation____

Expresses the equilibrium of a resting membrane potential and makes it possible to calculate the theoretical resting membrane potential.

Activators dramatically enhance the rate of transcription.

False

All functional DNA sequences inside a cell code for protein products.

False

All vesicular transport originates in the ER

False

Capstones are responsible for the first and most fundamental level of chromatin packing, the nucleosome.

False

Cell memory is where a parent cell signals where its daughter cells need to go.

False

Purines always base-pair with purines, and pyrimidines always base-pair with pyrimidines.

False

The Centromere contains repeated nucleotide sequences that are required for the ends of the chromosome to be replicated.

False

The plasma membrane is highly impermeable to all ions

False

The synthesis of ATP from ADP and Pi is a favorable reaction.

False

Pinocytosis is the only endocytic pathway where the cell takes in fluid

False (Phagocytosis also takes in fluids)

How does the Unfolded Protein Response regulate misfolded proteins?

It expands the area of the ER and halts translation

Which is true about membrane potentials?

It facilitates the creation of an electrochemical gradient

What amino acids do nuclear localization signals typically contain?

Lysines or arginines

Opening of ____ channels is controlling by a force applied to the channel

Mechanically-gated

Using the genetic code, what amino acid sequence is produced from the mRNA sequence 5'-AUGCUAGCUCGAUAUCUCUAG-3'?

Met - Leu - Ala - Arg - Tyr - Leu

What happens in an anabolic pathway?

Monomers are synthesized into polymers

What is the chloroplast equivalent of O2 in a mitochondrial ETC?

NADP+

BONUS What gas is synthesized from the amino acid arginine and diffuses readily from its site of synthesis into neighboring cells? What is its function in the cell?

Nitric oxide increases blood flow

Which two organelles are excluded form the endomembrane system?

Nucleus and mitochondria

The key difference between peroxisomes and lysosomes is that _______

Peroxisomes use primarily H202 (hydrogen peroxide)

What is the major difference between phagocytosis in animal cells and unicellular heterotrophs?

Phagocytosis in microorganisms is to obtain nutrients

What is the most abundant phospholipid in cell membranes?

Phosphatidylcholine

Which type of enzyme hydrolyzes peptide bonds?

Proteases

What enzyme turns a molecular switch on or off by phosphorylating it?

Protein Kinase

Which is not a transport protein used for passive transport?

Pumps

Which is not a stage of chemiosmotic coupling?

Pyruvate molecules are taken to the endoplasmic reticulum to be packaged for use by the mitochondrion

Which of the following statements about RNAi is TRUE?

RISC takes up one strand of the RNA, the remaining strand then seeks and destroys complementary foreign RNA molecules.

Unlike DNA, which typically forms a helical structure, different molecules of RNA can fold into a variety of three-dimensional shapes. This is largely because _____.

RNA is single-stranded

What makes iron-sulfur centers so successful as early carriers in the respiratory chain?

Relatively low electron affinity

What enzyme uses RNA as a template to synthesize DNA?

Reverse transcriptase

Which are NOT proteins that cross the ER membrane?

Ribosomes

Rab proteins serve as an attachment point for all of the following except..

SNARES

Converting the signals that carry information from one form to another is called _____

Signal transduction

After an amino acid has been linked to a peptide chain, the large ribosomal subunit shifts forward, moving the spent tRNA to which ribosome tRNA binding site before ejecting it?

Site E

Which is not a method of creating a membrane domain in the phospholipid bilayer?

Tethered to another cell

How did the mice respond in the optogenetics experiment when light-gated channels were added to their cells?

Their bodies moved towards the light

ATP is synthesized during the light reaction, or light dependent reaction.

True

Both the cytosolic and nuclear receptors are referred to as nuclear recptors

True

Primase is needed to initiate DNA replication on both the leading strand and the lagging strand.

True

Solutes in symports move in the same direction while solutes in antiports move in the opposite direction.

True

What does the electron-transport chain consist of?

a series of proteins with metals that serve as electron carriers

During RNA splicing _____ are excised and _____ are ligated.

introns; exons

How does an autophagosome work?

it surrounds a cell in a membrane and then fuses with a lysosome

Transcription is similar to DNA replication in that _____

nucleotide polymerization occurs only in the 5′-to-3′ direction

Fermentation occurs in the absence of _____

oxygen

Which posttranslational modification marks proteins to be located to the proteasome for protein degradation?

Ubiquitination

What are the major catalytic components of the spliceosome made up of?

Uracil-rich RNA

DNA is negatively charged.

True

What does ATP synthase use as an energy source for the production of ATP?

The proton motive force

Where in the photosystem of chlorophyll is light energy converted to chemical energy?

The reaction center

Which of the following does NOT occur before a eukaryotic mRNA is exported from the nucleus?

The ribosome binds to the mRNA.

Which is not a function of the components of intracellular signaling pathways?

Altering the signal

What does a protein need to enter the ER?

An ER signal sequence

What solute relies solely on the concentration gradient to cross the membrane?

Glucose

Which is not an energy source for active transport?

Glycolysis

Match each process with its locality within the cell

Glycolysis->The cytosol, Krebs's cycle->The mitochondrial matrix, ETC->Inner mitochondrial membrane

Which organelle functions as a packaging center and releases proteins in vesicles

Golgi apparatus

____ pumps create the electrochemical gradient needed for ATP synthase to synthesize ATP from ADP and an inorganic phosphate.

H+

What does the NADH dehydrogenase complex do in the ETC?

Hydrolyzes NADH

What would happen if an inhibitory neurotransmitter was blocked?

The body would convulse from constant contractions

You have a segment of DNA that contains the following sequence: 5′-GGACTAGACAATAGGGACCTAGAGATTCCGAAA-3′ 3′-CCTGATCTGTTATCCCTGGATCTCTAAGGCTTT-5′ You know that the RNA transcribed from this segment contains the following sequence: 5′-GGACUAGACAAUAGGGACCUAGAGAUUCCGAAA-3′ Which of the following choices best describes how transcription occurs? HINT: Directionality of the template strand, NOT the direction that RNA polymerase is moving

The bottom strand is the template strand; RNA polymerase moves along this strand from 3′ to 5′