Nucleic Acids Flashcards Preview

Foundations Of Medicine > Nucleic Acids > Flashcards

Flashcards in Nucleic Acids Deck (35)
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0
Q

Nucleotide

A

A base, sugar, and phosphate

1
Q

Location of DNA

A

The nucleus

2
Q

Nucleoside

A

Just a base and sugar

3
Q

Why is DNA so strongly held together?

A

All pairs have either double or triple hydrogen bonds and the planar bases allow more bonds per volume

4
Q

DNA backbone

A

Phosphate backbone linked by phosphodiester bonds

5
Q

The relatively stronger base pair

A

Cg, as it has three h bonds

6
Q

Groovy, man

A

Minor and major groove. Most DNA contacts made in major groove, where there is more room

7
Q

Three DNA conformations

A

B: right handed, normal
A: right handed, more compact, found in DNA RNA hybrids
Z: left handed, found transiently, during transcription

8
Q

Karyotype

A

The display of all 46 human chromosomes

9
Q

Chromosomes can be distinguished by

A

Size, staining patterns, and fish colour

10
Q

A gene contains

A

The DNA sequence that encodes the structural components of a gene product and regulatory elements that control its expression (promoter)

11
Q

Use of fish

A

Diagnosing chromosomal conditions

12
Q

Locus

A

A specific location on a chromosome

13
Q

Heterozygous vs homozygous alleles

A

If two genes functionally differ, they are heterozygous

14
Q

Homologous chromosomes

A

Corresponding chromosomes

15
Q

Conserved synteny

A

Same genes in the same order, but in different species

16
Q

Chromatin

A

A histone DNA complex that contains a large amount of arg and lys, the arg and lys neutralize the negatively charged DNA backbone

17
Q

Nucleosome

A

Basic unit of DNA packaging in eukaryotes. Basic unit of chromatin. DNA wound around histones

18
Q

Histone tails

A

Regulate histone structure and are subject to covalent modifications. Modified by acetylation and methylation of lysines and by phosphorylation of serines. HATs add histone acetyl groups and loosen up genes for expression. HDACs take off and tighten

19
Q

HATs

A

Histone acetyltransferases. Loosen up genes for expression

20
Q

HDACs

A

Histone deacetyltransferases. Silence genes by taking off acetyl groups. HDAC inhibitors have uses in anti cancer drugs, by stopping suppression of anti cancer genes.

21
Q

Histone acetylation

A

Crucial in destabilizing chromatin structure for replication. Acetyl group removes overall positive charge of lysine. Enzymes that modify are tightly regulated

22
Q

Euchromatin

A

Good to go. Open for transcription. Acetylation of tail histones is associated with euchromatin

23
Q

Heterochromatin

A

No go. Highly condensed, associated with de-acetylation. Can include HDACs like SIR proteins

24
Q

RNA

A

Runs 3’-5’.
Single stranded, but can form secondary and tertiary structures by base pairing upon itself. These looped regions are important for binding proteins and other molecules.
Can act as enzymes as ribozymes
M, r, and t are involved in protein synthesis

25
Q

mRNA

A

Messenger, codes for proteins

26
Q

rRNA

A

Ribosomal. Forms basic structure of ribosome and catalyzes protein synthesis

27
Q

tRNA

A

Transfer. Adapters between mRNA and aas. All have cloverleaf structure. Anti codon site binds to codon on mRNA . Have some modified nucleotides like ribothymidine. 3’ aa attachment site.

28
Q

snRNA

A

Small nuclear. Nuclear processes, including splicing of pre mRNA.

29
Q

snoRNA

A

Small nucleolar. Process and chemically modify mRNA

30
Q

scaRNA

A

Small cajal. Modifiy snoRNA and snRNA

31
Q

miRNA

A

Micro. Regulate gene expression by blocking translation of selected mRNA and chromatin formation. Key functions in cell differentiation. Mutations can cause cancer. Similar to siRNA.

32
Q

siRNA

A

Small interfering. Turn off gene expression by degrading mRNAs and establishing compact chromatin

33
Q

Processed mRNA

A

A 5’ guanosine cap, start codon, stop codon, poly a tail

34
Q

Ribosomes

A

Ribonecleoprotein structures on which protein synthesis occurs. Contain rRNA. Many loops and extensive base pairing.