Chapter 14 Vocab Flashcards Preview

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Flashcards in Chapter 14 Vocab Deck (43):
1

5' cap

A modified form of guan9ine nucleotide added onto the end of a pre mRNA molecule

2

A site

One of a ribosomes three binding sites for tRNA during translation. The A site holds the tRNA carrying the next amino acid to be added to the polypeptide chain

3

Alternative RNA Splicing

A type of eukaryotic gene regulation at the RNA processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exon and which as introns

4

Aminoacyl-tRNA synthase

An enzyme that joins each amino acid to the appropriate tRNA

5

Anticodon

A nucleotide triplet at one end of a tRNA molecule that base pairs with a particular complementary codon on an mRNA molecule

6

Codon

A three nucleotide sequence of DNA or mRNA that specifies a particular amino acid of termination signal, the basic unit of the genetic code

7

Deletion

A mutational loss of one or more nucleotide pairs from a gene

8

E site

One of a ribosomes three binding sires for tRNA during translation. The E site is the place where discharged tRNA's leave the ribosome

9

Exon

A sequence within a primary transcript that remains in the RNA after RNA processing, also refers to the region of DNA from which this sequence was transcribed

10

Frameshift mutation

A mutation occurring when nucleotides are inserted in or deleted from a gene and the number inserted or deleted is not a multiple of three, resulting in the improper grouping of the subsequent nucleotides into codons

11

Gene expression

The process by which information encoded in DNA directs the synthesis of proteins, or in some cases, RNAs that are not translated into proteins and instead functions as RNAs

12

Insertion

A mutation involving the addition of one or more nucleotide pairs to a gene

13

Intron

A noncoding, intervening sequence within a primary transcript that is removed from the rancript during RNA processing, also refers to the region of DNA from which this sequence was transcribed.

14

Messenger RNA

A type of RNA, synthesized using a DNA template, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein.

15

Missense mutation

A nucleotide pair substitute that results in a codon that comes for a different amino acid

16

Mutagen

A chemical or physical agent that interacts with DNA AND CAN CAUSE A MUTATION

17

Mutation

A change in the nucleotide sequence of an organisms DNA or in the DNA or RNA of a virus

18

Nonsense mutation

A mutation that changes an amino acid codon to one of the three stop codons, resulting in a shorter and usually non functional protein

19

Nucleotide pair substitution

A type of point mutation in which one nucleotide in a DNA strand and its partner in the complementary strand are replaced by another apri of nucleotides

20

P Site

On of a ribosomes three binding sites for tRNA during translation. The P sire holds the tRNA carrying the growing polypeptide chain

21

Point mutation

Idk

22

Poly-A-tail

A sequence of 50-250 adenine nucleotides added onto the 3' end of a pre mRNA molecule

23

Primary transcript

An initial RNA transcript from any gene, also called pre mRNA when transcribed from a protein coding gene

24

Promoter

A specific nucleotide sequence in the DNA of a gene that binds RNA polymerase, positioning it to start transcribing RNA at the appropriate place.

25

Reading frame

On an mRNA, the triplet grouping of ribonucleotides used by the translation machinery during polypeptide synthesis

26

Ribosomal RNA

RNA molecules that, together with proteins, make up ribosomes, the most abundant type of RNA

27

Ribosome

A complex of rRNA and protein molecules that functions as a site of protein synthesis in the cytoplasm; consists of a large subunit and a small subunit. In eukaryotic cells, each subunit is assembled in the nucleolus

28

Ribozyme

An RNA molecule that functions as an enzyme, such as an intron that catalyzes its own removal during RNA splicing.

29

RNA Polymerase

An enzyme that links ribonucleotides into a growing RNA chain during transcription, based on complementary binging to nucleotides on a DNA template strand

30

RNA Processing

Modification of RNA primary transcripts, including splicing out of introns, joining together of exon, and alternation of the 5' and 3' ends.

31

Silent mutation

A nucleotide pair substitution that has no observable effect on the phenotype; for example, within a gene, a mutation that results in a codon that codes for the same amino acid.

32

Spliceosome

A large complex made up of proteins and RNA molecules that splices RNA by interacting with the ends on an RNA intron, releasing the intron and joining the two. Adjacent exon

33

TATA Box

A DNA sequence in eukaryotic promoters crucial in forming the transcription inititation complex.

34

Template strand

The DNA strand that provides the pattern, or template, for ordering, by complementary base pairing, the sequence of nucleotides in an RNA transcript

35

Terminatior

In bacteria, a sequence of nucleotides in DNA that marks the end of a gene and signals RNA polymerase to release the newly made RNA molecule and detach from the DNA

36

Transcription

The synthesis of RNA using a DNA template

37

Transcription factor

A regulatory protein that binds to DNA and affects transcription of specific genes

38

Transcription initiation complex

The completed assembly of transcription factors and RNA polymerase bound to a promoter

39

Transcription unit

A region of DNA that is transcribed into an RNA molecule

40

Transfer RNA

An RNA molecule that functions as a trasnlateor between nucleoid acid and protein languages by picking up a specific amino acid and carryin it to the ribosome, where the tRNA recognizes the appropriate codon in the mRNA

41

Translation

The synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of "language" from nucleotides to amino acids.

42

Triplet code

A genetic information system in which a series of three nucleotide long words specifies a sequence of amino acids for a polypeptide chain.

43

Wobble

Flexibility in the base pairing rules in which the nucleotide at the 5' end of a tRNA anticodon can for. Hydrogen bonds with more than one kind of base in the third position (3' end) of a codon