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Flashcards in Nucleic Acids Deck (30):
1

4 items of chargaff's rules

1. the base composition of DNA varies from one species to the next
2. DNA specimens from different tissues of the same organism have the same base composition
3. the base composition of DNA in a given species does not change with age, nutritional state, or environment
4. A = T and G = C

2

primary level of DNA

the sequence of bases in a pair of complementary strands

3

the secondary level of DNA

the double helix

4

The tertiary level of DNA

super-coiled DNA

5

when do you find maximum coiling of DNA

during cell division

6

facilitates higher level coiling in the chromatin

H1 (a 5th histone)

7

three functions of the major groove

recognition sites for several transcription initiation factors
specific domains of initiation factors lie in major groove
promote separation of DNA strands

8

functions of the minor groove

much less is known
often bind smaller ligands which then can have several effects such as inhibiting cancer and antimicrobial activity

9

four stabilizing forces in DNA

1. hydrogen bonds between base pairs
2. hydrophobic interactions between base pairs and water
3. van der Waals forces
4. electrostatic interactions

10

cross like DNA structures that form when DNA contain a palindrome

cruciform DNA

11

a base sequence in DNA that provides the same information when read in either the forward or reverse directions

palindromes

12

four ingredients needed to complete the sanger sequencing

1. need to know something downstream of DNA strand wanted
2. need a primer
3. need bases/nucleotides
4. need dideoxybases

13

five steps in southern blotting

1. digestion of DNA by restriction enzyme
2. DNA fragments are separated by agarose gel electrophoresis
3. DNA fragments transferred to nitrocellulose filter paper for denaturing
4. the ssDNA on filter paper is hybridized by radioactively labeled ssDNA probe
5. any hybridized DNA can be sivualized by autoradiography

14

four characteristics of triple stranded DNA

1. form from partially unwound duplex DNA under super-helical" conformational stress
2. polypyrimidine segments folds back to interact with polypurine region of remaining duplex
3. third strand occupies the major groove of the original duplex
4. possible role in recombination

15

name of base pairing with the third strand in triple stranded DNA

hoogsteen base pairing

16

most commonly known transposon family in humans

alu family

17

a group of linked genes that are regulated as a unit

operon

18

a small circular, self replicating extra-chromosomal molecule of bacterial DNA

plasmid

19

non coding DNA sequences in eukaryotic genes

introns

20

coding DNA sequences in eukaryotic genes

exons

21

a non-functional sequence of DNA similar to a gene.
remnants of a once functional gene that accumulated mutations

pseudogenes

22

DNA sequences that excise, replicate, and insert themselves randomly elsewhere in the genome

tranposons

23

four main types of RNA

tRNA
mRNA
rRNA
snRNA

24

involved in splicing

snRNA

25

involved in preventing translation of target mRNA

miRNA

26

involved in RNA interference

siRNA

27

modified bases found in tRNA

pseudouridine
4-thiouridine
1-methylguanosine
dihydrouridine

28

where are amino acids linked in tRNA

to the 3' -OH group

29

functions of tRNA

carry amino acids to ribosome for assembly into polypeptides
at least one tRNA molecule for each of 20 different amino acids
anticodon base pairs with mRNA codons
often described as a adaptor molecule

30

structural elements of ribosomes

rRNA