1. Nucleic Acid Structure and Organization Flashcards Preview

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Flashcards in 1. Nucleic Acid Structure and Organization Deck (37):
1

DNA replication is..

The process in which each chromosome is duplicated before cell division

2

Where and when does transcription occur?

In the nucleus, throughout interphase

3

Where and when does translation of RNA occur?

In the cytoplasm, throughout the cell cycle

4

When and where does DNA replication occur?

In the nucleus, during S phase

5

What is M phase?

Mitosis, cell divides to form two daughter cells

6

What is interphase?

Time between two cell divisions/mitoses

7

When are genes expressed?

Throughout interphase

8

Phases of interphase are..

G1, S and G2

9

G1 phase is..

Period of cellular growth preceding DNA synthesis

10

G0 phase is..

Cells that have stopped cycling

11

S phase is..

DNA replication, leading to two identical chromatids

12

G2 phase is..

Period of cellular growth after DNA replication but preceding mitosis. Checked for errors.

13

S-phase chemotherapeutics

Methotrexate, r-fluorouracil, hydroxyurea

14

G2-phase chemotherapeutics

Bleomycin

15

M-phase chemotherapeutics

Paclitaxel, vincristine, vinblastine

16

Non cell-cycle specific chemotherapeutics

Cyclophosphamide, cisplatin

17

Checkpoints

Cyclins and cyclin-dependent kinases

18

Nucleotide components

Nitrogenous base, five-carbon sugar (pentose) and phosphate

19

Purines

Contain two rings. Adenine, guanine. (others: xanthine, hypoxanthine, uric acid)

20

Pyrimidines

Contain one ring. Cytosine, uracil, thymine

21

Nucleoside

Base added to number 1 carbon of sugar

22

Nucleotide

Nuclease + phosphate(s) to 5' carbon

23

Difference ribose and deoxyribose

Ribose has OH group at 2' carbon of the sugar, deoxyribose has H.

24

Nomenclature Base, Nucleoside, Nucleotide

Adenine-Adenosine-AMP
Guanine-Guanosine-GMP
Cytosine-Cytidine-CMP
Uracil-Uridine-UMP
Thymine-Deoxythymidine-dTMP

25

Nucleic acids

Linked by 3',5' phosphodiester bonds
Have distinct 3' and 5' ends, thus polarity
Sequence always specified as 5'->3'

26

Chargaff's Rules

%A = %T, %G = %C
% purines = % pyrimidines

27

DNA molecule

Mostly Watson-Crick DNA or B-DNA, right handed, 10 bps per complete turn of helix.
Left-handed rare in G-C rich sequences, Z-DNA.

28

Daunorubicin and doxorubicin

Exert their effects by intercalating between bases of DNA, interfering with topoisomerase II and preventing proper replication of DNA.

29

Cisplatin

Binds tightly to DNA, causing structural distortion and malfunction

30

Denaturation

Disrupt hydrogen bonding and base stacking
Heat, alkaline pH, chemicals (form amide, urea)

31

Supercoiling

Negative: more loosely wound (biological reactions)
Positive: more tightly
-> Topoisomerase, makes transient breaks

32

Histones are rich in

Lysine and arginine (positive charge)

33

Histone octamer

Two copies of each H2A, H2B, H3 and H4 aggregate

34

Nucleosome

DNA winds around outside of histone octamer
AKA beads on a string, 10nm chromatin fiber

35

Nucleofilament

H1 associates with nucleosome, 30nm fiber

36

Karyotype analysis uses..

Metaphase chromosomes, highly condensed

37

Banding techniques use..

Prophase or pro metaphase chromosomes