[1] LEC: DNA & RNA structure Flashcards
T/F: mRNA goes in and out of the nuclear membrane
F (cannot go back in again)
This part of the nuclear membrane is studded with ribosomes
Outer membrane
The inner nuclear membrane is connected to the ___
lamin
T/F: nucleotides are building block of DNA & RNA and they go out of the nuclear pore
F (they go in)
These bind to promoter region to act as signal for RNA to hop on
Transcription regulation factors
Components of the nucleolus
rRNA and CHONS
The histone protein is an octamere protein which has 8 units of different proteins, namely:
H2A
H2B
H3
H4
The ___ ___ is acted upon by the methyl transferase
CpG islands
They recognize CpG islands as an active site
Methyl transferase
This process is meant to bind the histones and DNA
methylation
The effect of methylation through 1 ion
opens up binding
The effect of methylation through 2-3 ions
tightens binding
The effect of acetylation
loosens binding
The H1 proteins is ___ charged, which enables linking with the phosphate group with ___ charge
+, -
Function of the H1 protein
chromatin compaction
transcription regulation
nucleosome spacing
chromosome spacing
The 5-carbon sugar ring component of the DNA
nitrogenous base
The 9-member double ring
purine
The 6-member single ring
pyrimidine
Identify the carbon number:
bind to nitrogenous base
1
Identify the carbon number:
bind to OH group
3
Identify the carbon number:
completes the cyclic structure
4
Identify the carbon number:
contains the phosphate group
5
When nitrogenous base and pentose sugar is bonded, they form ___ bond
glycosidic
When nitrogenous base and pentose sugar is bonded, they form ___
nucleoside
The bonding between the pentose sugar and a purine base is ___
covalent
The bond between phosphate group and the nucleoside forms ___ bond at 5’ hydroxyl group
phosphoester
The nucleoside is joined together through a ___ bond, which involves ___ reaction
phosphodiester
dehydration
Chargaff’s rules:
two long polynucleotide chains are coiled around a ___ axis, forming a ___-handed double helix
central
right
Chargaff’s rules:
the two DNA strand are ___, that is, their 5’ to 3’ orientation runs in ___ direction
antiparallel
opposite
Chargaff’s rules:
the base of both chains lie ___ to the axis, and they are stacked on one another
perpendicular
This indicates a definite pattern of base composition in DNA molecules
Chargaff’s rules
Chargaff’s rules:
the nitrogenous base of opposite chains are paired as the result of the formation of a ___ bond in DNA
hydrogen
Chargaff’s rules:
each complete turn of helix is ___ A
34
Chargaff’s rules:
the double helix has a diameter of ___ A
20
The nitrogenous base pairs are bonded by ___ bond
hydrogen
The sugar phosphate backbone is located on the ___
outside
The nitrogenous base is located on the ___ of the double helix structure
inside
Factors of complementary base pairing
geometrical location & interactions between functional groups
The major groove is ___ A long
22
The minor groove is ___ A long
12
Each repeat of double helix is ___ A
34
The distance between the adjacent nucleotides is ___ A
3.4
Each helix turn has approximately ___ base pairs
10
Each base pair rotates ___ degrees around the axis of the helix, completing a ___ degrees in 10 base pairs
36
360
If the DNA has >10 base pairs, it is called ___
overwound
If the DNA has <10 base pairs, it is called ___
underwound
Identify the DNA type:
extracted through dehydration or high salt conditions
A
Identify the DNA type:
Can be found in DNA-RNA & RNA-RNA hybrids
A
Compare:
A __ B
length
thickness
<
>
Each repeat of A DNA is ___ A
24.6
Each turn of A DNA has ___ base pairs
11
The major groove of __ DNA runs deep & narrow
A
The minor groove of __ DNA runs deep & narrow
Z
The minor groove of __ DNA runs shallow & broad
A
Identify the DNA type:
Extracted through high humidity
B
Identify the DNA type:
Most common form in vivo
B
Identify the DNA type:
Most common form in solution in vitro
B
The inside of the B DNA is ___ A
11
The outside of the B DNA is ___ A
20
One complete run of the B DNA is ___ A
34
Every turn of B DNA has ___ base pairs
10
Identify the DNA type:
Extracted through high salt concentration with the presence of alcohol
Z
Identify the DNA type:
Left handed
Z
Each repeat of Z DNA is ___ A
45.6
Each helical turn of Z DNA is ___ base pairs
12
tRNA constitute __% of the RNAs
15
The major groove of ___ DNA is very shallow to the point of virtually nonexistent
Z
This RNA carries amino acids to the ribosome during translation
tRNA
RNA polymerase I synthesizes ___
rRNA
RNA polymerase II synthesizes ___
mRNA & SnRNA
RNA polymerase III synthesizes ___
tRNA
Identify the RNA:
codes for proteins
mRNA
Identify the RNA:
form the basic structure of the ribosome and catalyze protein synthesis
rRNA
Identify the RNA:
central to protein synthesis as adaptors between mRNA and amino acids
tRNA
Identify the RNA:
function in a variety of nuclear processes, including the splicing of pre-mRNA
snRNA
Identify the RNA:
help to process and chemically modify rRNAs
snoRNA
Identify the RNA:
regulate gene expression by blocking translation of specific mRNAs and cause their degradation
miRNA
Identify the RNA:
turn off gene expression by directing the degradation of selective mRNAs and the establishment of compact chromatin structures
siRNA
Identify the RNA:
protect the germ line from transposable elements
piRNA
Identify the RNA:
many serve as scaffolds; they regulate diverse cell processes, including X-chromosome inactivation
lncRNA
