Bio Ch 14 Prt 2

Front 1

RNA polymerase

Back 1

Binds in a precise location on promoter, determining where transcription starts and which DNA strand is used as template/In bacteria, it recognizes and binds to promoter

Front 2

Transcription factors

Back 2

Group of proteins in eukary that mediate binding RNA poly and initiating transcription

Front 3

After transcription factors attach to promoter

Back 3

Only when this happens do RNA poly II bind to it

Front 4

Transcription initiation complex

Back 4

Complex of transcription factors and RNA poly II bound to the promoter

Front 5

TATA box

Back 5

Crucial DNA sequence in promoter

Front 6

Unwinds the two DNA strands

Back 6

When transcription factors are attached to promoter DNA and poly is bound to correct orientation, the enzyme does this and starts transcribing template strands

Front 7

10 - 20 DNA nucleotides

Back 7

RNA moves along DNA and untwists it, exposing _________ at a time for pairing w/ RNA nucleos/The enzyme adds nucleotides to 3' end of RNA molecule

Front 8

40 nucleotides per second

Back 8

Rate of transcription in eukary

Front 9

Transcribed simultaneously

Back 9

A single gene can be _______________ by several molecules of RNA poly following each other

Front 10

How far along the template the enzyme has traveled

Back 10

A growing strand of RNA trails from each poly, w/ the length of each new strand reflecting

Front 11

To make encoded protein in large amounts

Back 11

Group of many poly molecules simultaneously transcribing a single gene increases amount of mRNA transcribed, which helps cells __________

Front 12

Terminator sequence

Back 12

Bacteria's transcription proceeds through this in DNA

Termination signal

Causes poly to detach from DNA and release transcript

Front 13

RNA poly II

Back 13

In eukary, this transcribes the sequence on DNA called polyadenylation signal sequence, which codes for a polyden signal in pre-mRNA

Front 14

pre-mRNA

Back 14

At 10-35 nucleos downstream, from polyden signal, proteins associated w/ growing RNA transcript cut is free from the polymerase, releasing ___________, which then goes through processing

Front 15

RNA processing

Back 15

When enzymes in eukary nucleous modify pre-mRNA in specific ways before genetic messages go to cytoplasm

Front 16

5' end

Back 16

This end in pr-mRNA is processed first

Front 17

5' cap

Back 17

A modified form of guanine (G) added to 5' end after transcribing 20 - 40 nucleos

Front 18

3' end

Back 18

End of pre-mRNA modified before it leaves nucleous

Front 19

Poly-A-tail

Back 19

The 50-250 more adenines (A) added to 3' end

Front 20

5' cap and poly-A-tail shared functions

Back 20

Facilitate the export of mature mRNA from nucleus

Protect mRNA from degradation by hydrolytic enzymes

Help ribosomes attach to 5' end when mRNA reaches cytoplasm

Front 21

UTR

Back 21

Parts of mRNA not translated to protein and binds ribosomes

Front 22

27,000 nucleo pairs

Back 22

Length of transcription unit along human DNA and RNA

Front 23

Long non coding stretches

Back 23

Eukary genes have ____________ of nucleos untranslated

Front 24

Coding segments

Back 24

Most non coding sequences are interspersed b/ween __________ of genes

Front 25

DNA nucleo

Back 25

This sequence that codes for eukary polypeptide is usually not continuous, but split to segments

Front 26

Introns

Back 26

Non coding segments of nucleic acid b/ween coding regions (intervening sequences)

Front 27

Exons

Back 27

Other regions that are eventually expressed by being translated into amino acid squences

Front 28

UTR

Back 28

Part of exon which makes part of mRNA, but aren't made into proteins

Front 29

RNA splicing

Back 29

RNA poly II transcribes introns and extrons to make a primary transcript from a gene (mRNA is abridged version)/introns are cut and exons joined together forming mRNA molecule w/ continuous

Front 30

More than one kind of polypeptide

Back 30

The presence of introns in genes causes a single gene to encode ______________

Front 31

Alternative RNA splicing

Back 31

Genes giving rise to two or more different polypeptides, depending on which segments are treated as exons during RNA processing

Front 32

Spliceosome

Back 32

Proteins and small RNAs making a large complex that removes introns

Front 33

Released and rapidly degraded

Back 33

This happens to the introns, then the spliceosome joins the two exons flanking the intron

Front 34

Ribozome

Back 34

RNA molecules acting as enzymes

Front 35

Intron RNA

Back 35

Functions as ribosome and catalyzes its own excision

Front 36

Three properties that enable RNA to function as enzymes

Back 36

Being single stranded means a region of RNA can base-pair w/ a complementary region elsewhere/gives it 3D structure

Some RNA bases have functional groups that participate in catalysis

Can hydrogen bond w other nucleic acids which adds specificity to catalytic activity

Front 37

Transfer RNA tRNA

Back 37

Translator of message in a series of codons along mRNA

Front 38

Synthesizing them from other compounds or by taking them up from the surrounding solution

Back 38

Cells keep 20 amino acids in cytoplasm by _________

Front 39

The growing end of polypeptide chain

Back 39

The ribosome adds each amino acid brought by tRNA to _______________

Front 40

tRNA can translate an mRNA codon into amino acid

Back 40

Key to translating a genetic message into a specific amino acid sequence

Front 41

tRNA has amino acid at one end and a nucleic triplet that can base-pair w/ complementary codon on mRNA

Back 41

How can tRNA translate an mRNA codon into amino acid

Front 42

80

Back 42

tRNA has single RNA strand is ________ nucleotides long

Front 43

3D structure

Back 43

The presence of complementary stretches of nucleotide bases that can hydrogen bond to each other, the single strand can fold in on itself and form a molecule w/ ______________

Front 44

Anticodon

Back 44

Nucleotide triplet that base pairs to specific mRNA codon

Front 45

Glycine

Back 45

When an mRNA goes through ribosome ____________ is added to polypeptide chain when codon GGC is presented for translation

Front 46

Repeatedly

Back 46

The tRNA is used ___________ picking up designated amino acid in cytosol, deposits cargo on polypeptide chain at ribosome and leaving ribosome, is ready to start over

Front 47

A tRNA that binds to mRNA codon specifying amino acid must carry that and no other to ribosome

Pairing tRNA anticodon w/ appropriate mRNA codon

Back 47

Translation of genetic message needs two instances of molecular recognition

Front 48

Aminoacyl-tRNA synthetases

Back 48

Family of enzymes that match tRNA and amino acids

Front 49

20

Back 49

There are this many different synthetases, one for each amino acid

Front 50

Synthetases

Back 50

This is able to bind to all different tRNA that match codons of amino acids

Front 51

Hydrolysis of ATP

Back 51

Synthetases catalyzes covalent attachments of the amino acid to its tRNA in a process driven by the ___________________

Front 52

Charged tRNA

Back 52

Resulting aminoacyl tRNA that is released from the enzyme and available to deliver amino acid to polypeptide chain on ribosome

Front 53

Wobble

Back 53

Flexible base pairing at this codon position at third position at 3' end of an mRNA codon

Front 54

tRNA anticodons

Back 54

Ribosomes facilitate the coupling of ___________ w/ mRNA codons during protein synthesis

Front 55

Ribosomal RNAs rRNAs

Back 55

RNAs that make up ribosomes w/ proteins/most abundant type of RNA

Front 56

Proteins imported from the cytoplasm

Back 56

Ribosomal RNA genes are transcribed and the RNA is processed and assembled w/ _____________

Front 57

Nuclear pores

Back 57

The resulting ribosmal subunits are exported via ___________ to the cytoplasm

Front 58

Functional ribose

Back 58

Large and small subunits join to form ______________ only when they attach to mRNA

Front 59

1/3

Back 59

The mass of a ribosome are proteins/The rest are rRNAs (3 in bacteria, 4 in eukary)