Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Alex's Genetics > Lecture 14b > Flashcards

Lecture 14b Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

In regards to posttranslation regulation, what is another way to do this besides feedback inhibition?

A

Covalent modification of protein structure.

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

Is covalent modification of protein structure reversible or irreversible?

A

Both

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

What is proteolytic processing? Is this reversible or irreversible?

A

Proteins can be cleaved to become either active or inactive.

This is irreversible.

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

What is covalent modifications? Is this reversible or irreversible?

A

Adding sugars, lipids, etc. to proteins.

This is irreversible.

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

What is methylation? Is this reversible or irreversible?

A

Adding a methyl group to proteins.

This is reversible.

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

What is acetylation? Is this reversible or irreversible?

A

Adding COCH3 to make the protein slightly more negatively charged. The protein will now run differently on a gel right now.

This is reversible.

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

What is phosphorylation?

A

Adding a PO4 to proteins making it more negatively charged. This was one of the first ways studied.

This is reversible.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are transcription factors?

A

Proteins that influence the ability of RNA polymerase to transcribe a given gene.

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

What are the two types of transcription factors?

A

General transcription factors and regulatory transcription factors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are general transcription factors?

A

They are required for the binding of the RNA polymerase to the core promoter and its progression to the elongation stage.

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

What are general transcription factors necessary for?

A

Basal transcription.

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

What are examples of general transcription factors?

A

TFIID and TFIIH

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

What are regulatory transcription factors?

A

They serve to regulation the rate of transcription of target genes by enhancing or inhibiting gene expression.

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

What do regulatory transcription factors influence?

A

They influence the ability of RNA polymerase to begin transcription of a particular gene.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What percentage of human genes encode for regulatory transcription factors?

A

2-3% of human genes encode for regulatory transcription factors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a structural feature of regulatory transcription factors?

A

Transcription factor proteins contain regions, called domains, that have specific functions. The domains can be a module or part of a module.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What can the domains in regulatory transcription factors be used for binding wise?

A

One domain could be for DNA-binding. Another could provide a binding site for effector molecules causing genes to be expressed or shut down.

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

What is a motif?

A

A domain or portion of a domain that has a very similar structure in many different proteins.

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

What are the two types of motifs we learned about?

A

Helix-turn-helix motif and helix-loop-helix motif.

20
Q

What type of motif is seen in a lot of DNA-binding proteins?

A

Helix-turn-helix motifs.

21
Q

Do most proteins bind to the major or minor groove?

A

Major groove

22
Q

T/F: The second helix in a helix-loop-helix is binding to DNA.

A

False! It is not binding to the DNA.

23
Q

What type of motif is this?

A

This is a helix-turn-helix.

24
Q

What type of motif is this?

A

Helix-loop-helix motif.

25
Q

In regards to motifs, what occurs at the DNA major groove?

A

Recognition helix will recognize and make contact with a base sequence along the major groove of DNA.

26
Q

What is one way a transcription factor can bind to DNA?

A

Hydrogen bonding between an a-helix and nucleotide bases is one way.

27
Q

What is a Zinc Finger motif composed of?

A

Composed of one a-helix and two b-sheets held together by a Zn2+ metal ion.

28
Q

What does each Zinc Finger do?

A

Binds to 3 or 4 bases in the DNA using sequence-specific binding.

29
Q

What are leucine zipper motifs used for?

A

Used for dimerizing proteins.

30
Q

In leucine zipper motifs, how are proteins held together?

A

They are intertwined due to leucine motifs on the alpha helices which have hydrophobic interactions.

31
Q

How do we get protein dimerization?

A

Alternating leucine residues in both proteins will interact and “zip up” resulting in protein dimerization.

32
Q

What are Homodimers?

A

Formed by two identical transcription factors.

33
Q

What are Heterodimers?

A

Formed by two different transcription factors.

34
Q

What are transcriptional activators?

A

They bind enhancers to up-regulate transcription more than basal transcription.

35
Q

How do transcriptional activators enhance transcription?

A

They help to recruit TFIID and activate its function.

36
Q

What are co-activator proteins?

A

Some transcriptional activators require co-activator proteins to up-regulate transcription.

37
Q

Does the co-activator protein bind to the DNA?

A

No!

38
Q

What does an activator/coactivator complex do?

A

It recruits TFIID to the core promotor and activates its function, enhancing transcription.

39
Q

What are transcriptional repressors?

A

They bind silencers to down-regulate transcription to stop gene expression.

40
Q

How does a transcriptional repressor down-regulate transcription?

A

It inhibits the binding of TFIID to the TATA box or inhibits its function.

41
Q

T/F: Most enhancers and silencers are located within a few hundred nucleotides upstream of the promoter.

If true, what are some exceptions?

A

True!

However, some are several thousand nucleotides away, some are upstream or downstream of the promoter, and some are even within introns.

42
Q

What do mediators do?

A

They link enhancers and silencers to core promoters when they are far away.

43
Q

For transcriptional enhancement, what stimulates the mediator?

A

Transcriptional activator stimulates the function of the mediator to recruit the RNA polymerase.

44
Q

When the mediator recruits RNA polymerase, what happens as a result?

A

RNA polymerase forms a preiniation complex and proceeds to the elongation phase of transcription.

45
Q

What inhibits the function of the mediator?

A

Transcriptional repressor inhibits the activator function of mediator.

46
Q

Does the transcriptional repressor or the mediator repress transcription?

A

Transcription is repressed by the mediator.

Alex's Genetics (38 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions