Alberts, Ch 6 - From DNA to Protein

Question 1

Anticodon

Answer 1

Sequence of three nucleotides in a tRNA molecule that is complementary to a three-nucleotide codon in mRNA molecule

Question 2

Consensus nucleotide sequence

Answer 2

A summary or average of a large number of individual nucleotide sequences derived by comparing many sequences with the same basic function and tallyingup the most common nucleotides found in that position

Question 3

DNA supercoiling

Answer 3

Conformation with loops or coils tht DNA adopts in response to superhelical tension, conversely creating various loops or coils in the helis can create such tension

Question 4

Eukarotic initiation factors (eIF)

Answer 4

Protein that helps oad initiator tRNA on to the ribosome initiating translation

Question 5

Exon

Answer 5

Segment of eukaryotic gene that consists of a sequence of nucleotides that will be represented in mRNA or final mature RNA molecule, codes for amino acids in protein-coding genes, usually next to introns

Question 6

Exosome

Answer 6

Large protein complex with an interior richin 3’-to-5’ RNA exonucleases, degrades RNA molecules to produce ribonucleotides

Question 7

General transcription factor

Answer 7

Any of the proteins whose assembly at all promoters if given gene type is required for the binding and activation of RNA polymerase and initiation of transcription

Question 8

Genetic code

Answer 8

Set of rules specifying the correspondence between nucleotide triplets in DNA, codons in RNA and amino acids in proteins

Question 9

Induced fit

Answer 9

Principle for increasing specificity of substrate recognition by proteins and RNAs, in protein synthesis a ribosome/enzyme folds around codon-anticodon interaction and only when match is correct is subsequent reaction allowed to proceed

Question 10

Initiator tRNA

Answer 10

Special tRNA. That initiates translation, carries amino acid methionine, forming complex Met-tRNAi

Question 11

Intron

Answer 11

Noncoding region of eukaryotic gene that is transcribed into RNA molecule but is then excised by RNA splicing during production of mature RNA molecule

Question 12

Kinetic proofreading

Answer 12

Principle for increasing the specificity of catalysis, in synthesis of DNA, RNA and proteins it refers to a time delay that begins with irreversible step and during which incorrect base pairs are more likely to dissociate that correct pairs

Question 13

Molecular chaperone

Answer 13

Protein that helps guide proper folding of other proteins or helps them avoid misfolding

Question 14

Messenger RNA (mRNA)

Answer 14

RNA molecule that specifies the amino acid sequence of a protein, produced in eukaryotes by processing of RNA molecule, translated into protein

Question 15

Noncoding RNA

Answer 15

RNA molecule that is the final product of a gene and does not code for protein, these RNAs serve as enzymatic, structural and regulatory components for a wide variet of processes in the cell

Question 16

Nonsense-mediated mRNA decay

Answer 16

Mechanism for degrading aberrant mRNAs containing in-frame internal stop codons before they can be translated into protein

Question 17

Nuclear pore complex (NPC)

Answer 17

Large multiprotein structure forming an aqueous channel through the nuclear envelope that allows selected molecules to move between nucleus and cytoplasm

Question 18

Promoter

Answer 18

Nucleotide sequence in DNA to which RNA polymerase binds to begin transcription

Question 19

Proteasome

Answer 19

Large protein complex in cytosol with proteolytic activity that is responsible for degrading proteins that have been marked for destruction by ubiquitylation or some other means

Question 20

Reading frame

Answer 20

Phase in which nucleotides are read in sets of three to encode a protein, mRNA molecule can be read in any one of three reacing frames, only one of which will give the required protein

Question 21

Ribosome

Answer 21

Particle composed of rRNAs and ribosomal proteins that catalyze the synthesis of protein using information provided by mRNA

Question 22

Ribosomal RNA (rRNA)

Answer 22

Aany one of a number of specific RNA molecules that form part of the structure of a ribosome and participate in synthesis of proteins, often distinguished by sedimentation coefficient

Question 23

Ribozyme

Answer 23

RNA molecule with catalytic activity

Question 24

RNA polymerase

Answer 24

Enzyme that catalyzes synthesis of RNA molecule on a DNA template from ribonucleoside triphosphate precursors

Question 25

RNA polymerase II

Answer 25

RNA polymerase that catalyzes the formation of precursor-mRNAs

Question 26

RNA splicing

Answer 26

Process in which intron sequences are excised from RNA transcripts, major process in nucleus of eukaryotic cells leading to formation of mRNA

Question 27

RNA world

Answer 27

Hypothesis that early life on Earth was based primarily on RNA molecules that both stored genetic information and catalyzed biochemical reactions

Question 28

rRNA gene

Answer 28

Gene that specifies ribosomal RNA

Question 29

Small nuclear RNA (snRNA)

Answer 29

Small RNA molecules that are complexed with proteins to form ribonucleoprotein particles (snRNPs) involved in RNA splicing

Question 30

Small nucleolar RNA (snoRNA)

Answer 30

Small RNAs found in nucleolus with various functions including guiding the modifications of precursor rRNA

Question 31

Spliceosome

Answer 31

Large assembly of RNA and protein molecules that performs pre-mRNA splicing in eukaryotic cells

Question 32

TATA box

Answer 32

Sequence in promoter region of many eukaryotic genes that binds a general transcription factor (TFIID) and hence specifies position at which transcription is initiated

Question 33

Terminator

Answer 33

Signal in bacterial DNA thathalts transcription, in eukaryotes terminates after cleavageand polyadenylation of newly synthesized RNA

Question 34

DNA transcription

Answer 34

Copying of one strand of DNA into a complementary RNA sequence by RNA polymerase

Question 35

Transfer RNA (tRNA)

Answer 35

Set of small RNA molecules used in protein synthesis as an interface between mRNA and amino acids, each type of tRNA molecule is covalently linked to a particular amino acid

Question 36

Translation

Answer 36

Process by which the sequence of nucleotides in an mRNA molecule directs incorporation of amino acids into protein, occurs on ribosome

Question 37

Aminoacyl-tRNA synthetase

Answer 37

Enzyme that attaches the correct amino acid to a tRNA molecule to form an aminoacyl-tRNA