Ap Bio Midterm - Chapter 17

Front 1

Synthesis of RNA under the direction of DNA; copied from one molecule to another; DNA serves as a template for the RNA nucleotides

Back 1

Transcription

Front 2

Carries the message from the DNA to the ribosome

Back 2

Messenger RNA (mRNA)

Front 3

Synthesis of a polypeptide, occuring under the direction of mRNA

Back 3

Translocation

Front 4

Yields the finished mRNA - primary transcript

Back 4

RNA processing

Front 5

Genetic instructions for a polypeptide chain are written in the DNA as a series of three-nucleotide words

Back 5

Triplet Code

Front 6

DNA strand; provides the template for ordering the sequence of nucleotides in a RNA transcript

Back 6

Template strand

Front 7

mRNA base triplets; read in 5' - 3' direction; number of nucleotides making up a genetic message much be three times the number of amino acids

Back 7

Codons

Front 8

Groupings that help us read the genetic messages

Back 8

Reading Frame

Front 9

Pries the two strands of DNA apart and hooks together the RNA nucleotides as they base-pair along the DNA template; can add nucleotides only to the 3' end of the growing polymer - 5' - 3' direction

Back 9

RNA polymerase

Front 10

DNA sequence where RNA polymerase attatches and initiates transcription

Back 10

Promoter

Front 11

Sequence that signals the end of transcription

Back 11

Terminator

Front 12

Stretch of DNA that is transcribed into an RNA molecule

Back 12

Transcription unit

Front 13

Eukaryotes only; collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription

Back 13

Transcription factors

Front 14

Completed assembly of transcription factors and RNA polymerase bound to the promoter

Back 14

Initiation (transcription) complex

Front 15

Helps form the initiation complex

Back 15

TATA Box

Front 16

Helps protect the mRNA from degradation by hydrolytic enzymes; after mRNA reaches the cytoplasm, it's an "attatch here" sign for ribosomes - guanacine triphosphate (modified guanine)

Back 16

5' Cap

Front 17

3' end - 50 - 250 Adenine nucleotides; inhibits degradatoin; also facilitates of mRNA from the nucleus; also shares the nontranslated leader and trailer segments of RNA to which they are attatched

Back 17

Poly (A) tail

Front 18

Removal of a large portion of the RNA molecule that is initially synthesized

Back 18

RNA splicing

Front 19

Noncoding segments of nucleic acid that lie between coding segments

Back 19

Introns

Front 20

Translated into amino acid sequences, exiting the nucleus

Back 20

Exons

Front 21

Recognize splicing sites; composed of RNA (snRNA) and protein molecules - binds at beginning of intron

Back 21

snRNPs

Front 22

Interacts with the splice sites at the ends of an intron, cuts at specific points to release the intron, then joins togteher the two exons that flanked the intron

Back 22

Spliceosome

Front 23

RNA molecules that function as enzymes; helps the idea of a catalytic role for snRNA

Back 23

Ribozymes

Front 24

Discrete functional and structural regions

Back 24

Domains

Front 25

Interpretator of the message of series of codons; transfer amino acids from the cytoplasm's amino acid pool to a ribosome; folds with hydrogen bonds

Back 25

Transfer RNA (tRNA)

Front 26

Holds tRNA with polypeptide chain

Back 26

P Site

Front 27

Holds tRNA with amino acid to be added

Back 27

A site

Front 28

Exit site for empty tRNA

Back 28

E site

Front 29

Marks the protein to the ER or for secretion - about 20 amino acids at or near the leading (amino) acid of the polypeptide recognized as it emerges from the ribosome by signal-recognition partical (SRP)(protein-RNA complex)

Back 29

Signal peptides

Front 30

Changes in the genetic material of a cell (or virus)

Back 30

Mutation

Front 31

Chemical changes in just one base pair of a gene

Back 31

Point mutation

Front 32

Replacement of one nucleotide and its partner in the complementary DNA strand with another pair of nucleotides

Back 32

Base-pair substitution

Front 33

No effect on the encoded protein

Back 33

Silent mutation

Front 34

The attended codon still codes for an amino acid

Back 34

Misssense mutation

Front 35

Alterations that change an amio acid codon to a stop signal - nonfunctional proteins

Back 35

Nonsense mutation

Front 36

Alteratoin of the reading frame - occurs whenever the number of nucleotides inserted or deleted is not a multiple of three

Back 36

Frameshift mutation

Front 37

Physical and chemical agents that interact with DNA to cause mutations

Back 37

Mutagens

Front 38

64 possible codons but only 20 amino acids, most amino acids are encoded for by more than one codon, difference occurs in the 3rd base, may help to prevent mutations from altering protein structure

Back 38

Redundency in Genetic Code