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#‼️BIOCHEMISTRY - PLE TOPNOTCH 2020 > GENETICS > Flashcards

Flashcards in GENETICS Deck (53)
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1

DNA TO RNA

Transcription 

2

RNA to DNA 

Reverse Transcription 

3

RNA to Proteins 

Translation 

4

Histones have a high content of what AA. 

arginine and lysine

5

The process of disrupting the double helix is called

denaturation

6

Thymine = Adenine has how many Hydrgen bonds?

2

7

Cytosine = Guanine has how many hydrogen bonds

3 (stronger)

*Note that there are three hydrogen bonds between GC and just two

hydrogen bonds between AT. Thus, DNA strands with a greater

proportion of GC nucleotide pairs will be more difficult to separate.

8

Copies genetic information from DNA and serves as the template for protein synthesis

MESSENGER RNA (mRNA)

9

Prokaryotes have _______ subunits, made up of 3 types of rRNA: 16S, 23S, and 5S

50S and 30S

10

Differentiate DNA and RNA 

11

MESSENGER RNA (mRNA) structure 

  • In eukaryotes
    • Methylguanosine cap at the 5’-end
    • Poly(A) tail at the 3’-end
  • The primary transcript undergoes splicing prior to protein synthesis

12

Contribute to the formation and function of ribosomes, which act as the site for protein synthesis

RIBOSOMAL RNA (rRNA)

13

Eukaryotes have ______ subunitis, made up of four types of cytosolic rRNA: 18S, 28S, 5S, 5.8 S

60S and 40S

14

Adapter molecules that translate the nucleotide sequence of mRNA into specific amino acids

TRANSFER RNA (tRNA)

15

DNA REPLICATION occurs during what phase of the cell cycle?

S phase

16

The origin of replication (ori) is recognized by a group of proteins called ____

origin recognition complex (ORC)

17

___unwinds the double helix, in a process that is driven by ATP

Helicase

18

maintain the separation of the parent strands

Single-stranded DNA-binding proteins

19

relieve torsional strain that results from helicase-induced unwinding

Topoisomerases

o Type I (Swivelase)

o Type II (Gyrase), inhibited by fluoroquinolones

20

synthesizes short segments of complementary RNA primers

Primase 

21

elongates the DNA strand by adding new deoxyribonucleotides

 

DNA polymerase III

  • Synthesis proceeds in the 5’ to 3’ direction only
  • Leading strand is synthesized continuously
  • Lagging strand consists of Okazaki fragments
  • Mismatched nucleotides are removed using the enzyme’s 3’→5’ exonuclease (proofreading)

22

When another primer is reached, _____ removes the ribonucleotides using its 5’→3’ exonuclease

DNA polymerase I

*fills the gap with deoxyribonucleotides

23

seals the nick by catalyzing the formation of the last phosphodiester (joins 2 nucleotides) bond, requiring hydrolysis of ATP

DNA ligase

24

DNA Lesion: Mismatched Strand

25

DNA lesion: Pyrimidine dimers (Usually thymine)

26

DNA Lesion: Base alterations (e.g., cytosine to uracil, or guanine to xanthine)

27

DNA Lesion:  DOuble strand breaks

28

inhibits topoisomerase

Etoposide

29

Enzyme for Transcription (DNA to RNA)

Enzyme: DNA-dependent RNA polymerase

  • No primer needed, no proofreading activity
  • In eukaryotes, the polymerases synthesize specific RNA molecules:

30

o ______are DNA sequences that stimulate transcription rate

o _______ inhibit transcription

Enhancers

Silencers