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Flashcards in NEW 3 Deck (40):
1

Amino acid sequence of protein is written...

in DNA

2

RNA has a series of...

NONoverlapping three base “words” called codons

3

Transcription rewrites the DNA ---> RNA, substituting..

U for T
Uracil for Thymine

A + U in RNA**

4

Each amino acid is...

specified by codon

5

__ codons are possible

64

6

Some amino acids have more than...

one possible codon

7

Genetic code decides how codons are...

translated into amino acids

8

Three nucleotides specify ONE...

amino acid in the genetic code

9

61 codons correspond...

to amino acids

10

AUG

-START of TRANSLATION

-codes for methionine

11

3 “stop” codons signal...

end of translation

12

Genetic Code

is universal, shared by organisms from simple to complex

13

RNA molecule is _______ from gene

transcribed

14

RNA polymerase

RNA nucleotides linked by transcription enzyme

15

Promoter

nucleotide sequence signal = “start transcribing”

15

Cap and tail of extra nucleotides are added to ends of the mRNA to...

-help RNA leave nucleus

-protect RNA from damaging enzymes

-help RIBOSOMES bind to mRNA

16

INITIATION

RNA polymerase CONNECTS to promoter

17

ELONGATION

-amino acids added ONE by ONE

-RNA grows longer

18

Removes introns and joins exons producing continuos coding sequence

RNA splicing

19

TERMINATION

-RNA polymerase reaches base in DNA template called TERMINATOR, signals the END of gene

-polymerase detaches from RNA molecule and gene

20

tRNA molecules
picks up _____ _____ and brings them to _______

amino acids

cytoplasm

21

Translation - can be divided into same...

three phases as transcription:

1 ) initiation

2) elongation

3) termination

22

Ribosomes are composed of...

ribosomal rRNAs and protein

23

Ribosomes have binding sites for...

mRNA and tRNAs

24

Messenger RNA (mRNA)*


-encodes amino acid sequence

25

tRNA molecules use special...

TRIPLET of bases called anticodon

26

P site

first tRNA occupies the p site, which holds growing polypeptide chain

28

A site

available for next tRNA (transfer RNA)

28

Translation termination

-ribosome reaches STOP codon

-completed polypeptide is released from the last tRNA

-ribosome goes back into separate subunits

29

3 types of Mutations

1) base substitution

2) insertions

3) deletions

30

anticodon

-triplet bases

-complements codons in mRNA

31

Any change in nucleotide sequence of DNA

mutation

32

Base substitution

1) have NO effect, silent mutation

2) leads to IMPROVED protein that helps enhance survival

3) nonsense mutation

33

Mutations can involve large chromosomal regions or...

just single nucleotide pair

34

Mutations caused by...

random errors during DNA replication

35

Mutagens: cause _______

mutations
ex. high energy radiation, chemicals

37

Nonsense mutation

CHANGES amino acid into stop codon

38

Insertions & Deletion mutations

-alter reading frame

-produce NONFUNCTIONAL polypeptide

-change in amino acid sequence downstream of mutation

38

Codons are ____ to each other, NO gaps in between

next

39

mRNA contains INtrons...

interrupts sequences that separates exons