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Flashcards in DNA and Biotechnology Deck (82)
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1

Nucleosides

C1' of a pentose sugar binds covalently to a nitrogenous base

2

Nucleotides

1-3 phosphate groups attached to C5'; high energy because of (-) charge repulsion
-Adenine(A), Guanine(G), Cytosine(C), Uracil (U), Thymine (T)

3

RNA pentose

Ribose

4

Ribose (know structure)

.

5

DNA pentose

Deoxyribose and know its structure

6

DNA is read

5' to 3'

7

Orientation of phosphodiester bonds

3' to 5'; link 3' carbon of one sugar to 5' phosphate group of next incoming sugar

8

5' end of DNA

Has alcohol or phosphate group

9

3' end of DNA

-OH group

10

Nitrogen containing bases

Purines and pyramidines

11

Purines

Heterocycles with 2 rings
Adenine and Guanine A&G

12

Pyramidines

Heterocycles with 1 ring
Cytosine, Thymine, Uracil

13

Aromatic

-Stable ring
-cyclic, planar, alternating pi bonds and/pr lone pairs
- 4n+2 pi/lone electrons

14

Antiparallel DNA strands

5' to 3' and 3' to 5'

15

DNA structure

Sugar-phosphate groups on outside and nitrogenous bases inside

16

Hydrogen bonds in DNA

AT has double hydrogen bonds and GC has triple hydrogen bonds

17

% Purines is equal to

% Pyramidines

18

5'ATCG3' is complementary to

5'CGAT3'

19

B DNA

most DNA in this form; right handed helix

20

Major and minor grooves

Protein binding sites

21

Z DNA

Zig-zag appearance; left handed; high GC content or high salt concentration environment

22

What denatures DNA?

Heat, alkaline pH, and chemicals like formaldehyde and urea
-Base pair hydrogen bonds are disrupted but backbone stays intact

23

How to reanneal denatured DNA?

Remove denaturing environment

24

Histones

DNA wraps around histones to make nucleosomes
Stable, beads on a string
Nuceloproteins

25

When does DNA replication occur?

S phase

26

Heterochromatin

Compacted, transcriptionally silent, dark, has repetitive DNA sequences

27

Euchromatin

Light, genetically active, dispersed

28

Telomere

Simple repeating unit at end of DNA, have high GC content, strong strand attractions to keep ends stable

29

Telomerase

Replaces lost telomere parts during replication

30

Aging

Progessive shortening of telomeres can lead to this