Biochem Ch 1-3 Flashcards Preview

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Flashcards in Biochem Ch 1-3 Deck (177)
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1

chemo drugs that act in S phase

- methotrexate, 5-flurouracil, hydroxyurea
- interfere with thiamine (only in DNA) synthesis

2

chemo drugs that act in G2 phase

bleomycin

3

chemo drugs that act in M phase

paclitaxel, vincristine, vinblastine

4

non cell-cycle specific chemo drugs

cyclophosphamide, cisplatin

5

Nucleoside

base + 5C sugar

6

Pyrimidines

- Cytosine, uracil, thymine
- "CUT the Py"
- if you deaminate C, you get U
- Uracil is only in RNA
- difference between U and T = T has a methyl group
- Thymine is only in DNA
- Cytosine is in both DNA/RNA
- structure is 1 ring
- "More complex name, more simple structure"

7

Nucleoside of Adenine and Guanine

Adenosine (deoxyadenosine), Guanosine (deoxyguanosine)

8

Nucleotide

base + 5C sugar + phosphate

9

Nucleoside of cytosine

cytidine (deoxycytidine)

10

nucleoside of uracil

uridine (deoxyuridine)

11

nucleoside of thymine

deoxythymidine (BC only in DNA)

12

MOA for daunorubicin and doxorubicin

- Anti tumor drugs used to treat leukemias
- intercalating between the bases of DNA, thereby interfering with the activity of topoisomerase II and preventing proper replication of the DNA

13

Purines

- Adenine and Guanine
- if you deaminate A you get G
- Purines have 2 ringed structures
- "PURe As Gold"

14

MOA of cisplatin and use

- antitumor drug used to treat bladder and lung tumors
- bind tingtly to the DNA, causing structural distortion and malfunction

15

negative vs positive supercoiling

negative superoiling = DNA is wound MORE LOOSELY than watson-crick DNA

positive supercoiling = DNA is wound MORE TIGHTLY than watson-crick DNA

16

How to topoisomerases work? and example

They change the amount of supercoiling in DNA molecules by making transient breaks in DNA strands by alternately breaking and resealing the sugar-phosphate backbone.

ie E. Coli DNA gyrase (DNA Topoisomerase II) can introduce negative supercoiling in DNA

17

nucleosome

DNA wrapped 2x around 8 histones: (2 H2A, 2 H2B, 2 H3, 2 H4 = a histone octamer)

H1 = associated w the linker DNA found between the nucleosomes to help package them into a solenoid-like structure (a thick 30 nm fiber)

18

what amino acids predominate in histones?

lysine and arginine. both have a + charge and confer a positive charge on the proteins

19

Why does DNA have a negative charge?

because between every 5C sugar there is a phosphate with a negative charge

20

euchromatin

- light staining
- transcripturally active genes
- apoptois
- more opened and available for gene expression
- ie insulin gene in pancreas

21

heterochromatin

- dark staining
- transcripturally inactive genes
- highest order packaging
- condensed and associated with areas of chromosomes that are NOT expressed
- ie insulin gene in muscle
- MITOTIC DNA = MOST CONDENSED DNA to allow separation of the sister chromatids= no gene expression.

22

anything ending in "-in"

protein!

23

Double stranded DNA associates together via

hydrogen bonding

24

nucleotide

phosphate group is attached to the 5' C of a nucleoside

25

characteristic features of eukaryotic cell death (in nucleus) by apoptosis

endonuclease activation and chromatin fragmentation

26

circular DNA double helices

- bacterial chromosome
- bacterial plasmid
- mitochondrial chromosome

27

most viral genomes are

SSDNA
- an example of an exception = parvovirus

28

mitochondrial DNA is found in the

cytoplasm (like in bacteria)

29

RNA is made in the (location)

nucleus and is moved to the cytoplasm

30

examples of cells in G0

cells that don't replicate
- muscle, liver, nerve cells
- these cells still undergo transcription, because gene EXPRESSION does occur