Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Medicine Sem 2 > Molecular biochemistry W10 > Flashcards

Molecular biochemistry W10 Flashcards

(48 cards)

Start Studying
1
Q

Where does Noncoding RNAs serve as intermediates

A

In the central dogma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is rRNA and tRNA essential for

A
  • Protein synthesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What does telomerase RNA serve as a template fro

A
  • Serves as a template for telomere replication
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

WHt does snoRNAs modify

A

They modify ribosomal RNA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does is snRNA important in

A

RNA splicing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does Xist RNA inactivate

A

One X chromosome in females

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the function of ncRNAs

A
  • Help regualte gene expression and
  • protect the genome from virsues and transposons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Explain how short ncRNAS function in RNA interference (RNAi)
-what they act as
-what they bind and what this leads to

A
  • Short ncRNAs act as guide RNAs.

They bind to specific mRNAs by base-pairing, leading to:

Translation inhibition.

mRNA degradation.

Chromatin remodeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Name the 3 key types of small noncoding RNAs

A
  • miRNAs( microRNAs)
    -siRNAs(small interfering RNA)
  • piRNAs( piwi interacting RNAs)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is miRNAs- microRNAs synthesized by

A
  • RNA polymerase 2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does miRNAs regulate

A

Regulate translation and stability of at least one third protein coding genes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is miRNA incorporated into

A

RISC( RNA- induced silencing complex) which targets mRNA via base pairing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does siRNAs and PiRNAs reduce

A

Gene expression

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Name a protein that is part of the RISC + function

A
  • Argonaute, It positions the 5’ region of miRNA for base-pairing with target RNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the advantages of miRNAs

A
  • A single miRNA can regulate many mRNAs sharing common seqeuence
  • miRNAs are small but impactful, therfore effiecnt use of genome space
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Explain what is combinatorial control in relation to miRNAs

A
  • Where multiple miRNAs can target the same mRNA, increasing repression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What else does miRNA function in

A

Defense by degrading foreign dsRNA from viruses or transposons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Explain the evolutionary perspective of siRNAs and miRNAs

A

siRNAS- acient and widespread
miRNAS- evoolved later as refinement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Name the compoentns that form the RITS complex(RNA - induced transcriptional silencing)

A
  • siRNAS+ Argonaute+ other proteins form the RITS complex
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does the RITS complex bind + recruit + what does this binding and recruting lead to

Study These Flashcards
A
  • Binds nascent RNA transcripts
    and recruits chromatin-modifying proteins
    This leads to :
  • Histone modifications
    -Heterochromatin formation
    -Gene silencing
21
Q

What happens in the positive feedback loop in relaltion to RITS complex- what does it recruit and whay

Study These Flashcards
A
  • It recruits RNA dependent RNA polymerase and dicer to sustain siRNA production
22
Q

What are the functions of positive feedback loop

Study These Flashcards
A
  • Silencing of transposable elements
    -Maintenance of centromeric heterochromatin for chromosome segregation during mitosis
23
Q

What is the primary role of piwi -interacting RNAs( piRNAs)

Study These Flashcards
A

To silence transposable elements

24
Q

Compare piRNAs to miRNAS /siRNAs

Study These Flashcards
A
  • They are longer then miRNAs/siRNAs
    -Do not require Dicer enzyme for processing
25
What are piRNAs associated with
Associated with Piwi proteins
26
What are piRNAs transcribed from
Transcribed from genomic clusters of transposon sequemce fragments
27
What are piRNAs processed into
- short single strands
28
What do scientists use RNAi for
To inactivate specific genes in cultured cells
29
What medical use could RNAi have
In gene therapy
30
What is RNAi used by cells for
For gene regulation and chromosome structure maintenance
31
What does RNAi stand for
RNA interference
32
What does bacteria and aracheae used to protect against viral infectiosn
CRISPR systems
33
Name the 3 key steps of the CRISPR system
-Integration -Transcription -Targeting
34
Explain what happens in the integration step in the CRISPR mechanism
- Fragments of viral DNA are inserted into CRISPR loci in the host genome, forming a genetic memory
35
Explain what happens in the transcription step in the CRISPR systems
- The loci are transcribed into long RNAs and processed into crRNAs( CRISPR RNAs)
36
What happens in targeting steps
crRNAs asscoiate with CAS proteina to seek out and destroy mathcing vira double stranded DNA
37
What is the CRISPR system also similar to and how
Adaptive immunity: as it remembers and targets previosuly encountered viruses
38
What are CAS proteins functionally similar to + what have they been engineered for
- Argonaute proteins+ piwi proteins -Engineered for genome editing in plants and animals
39
What does IncRNAs stand for
Long NONcoding RNAs
40
What is lncRNA transcribed by
RNA polymerase 2
41
Name 2 unifying functional mechanism of lncRNA
1. Scaffold function 2. Guide function
42
What happes in scaffold function+ what does the structure allow
- lncRNA bring proteins together to coordinate their actions -The structure allos them to bind to various proteins
43
What happens in guide function
lncRNA binds to DNA or RNA via base pairing to guide proteins to specific sequences
44
IncRNA similar to the guide function of what
- similar to the guide function of miRNAs, crRNAs and snoRNAs
45
What does Antisense IncRNAs transcribe + WHY DO THEY Bind to mRNAs
- They transcribe opposite protein coding genes - Bind to mRNAs to block translation or alter splicing
46
What do sponge IncRNAs bind to + effect
Bind to miRNAs and inhibit their function
47
What can some IncRNAs be
- Cytoplasmic or nuclear (which is the well understood ones)
48
What does RNAi use to regulate mRNA and gene expression
Uses miRNA, siRNA and piRNA

Medicine Sem 2 (47 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions