Gene Technology- Genome Projects and Making DNA Fragments Flashcards

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

What is a genome?

A

The entire set of DNA, including all the genes in an organism

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

What have improvements in technology allowed us to do?

A

To sequence the genomes of a variety of organisms

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

What do gene sequencing methods only work on?

A

Fragments of DNA which are sequenced and then put back in order to give the sequence of the whole genome

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

What was the Human Genome Project and when was it completed?

A

Mapped the entire sequence of the human genome for the first time in 2003

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

What is a proteome?

A

All the proteins that are made by an organism

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

What type of organisms don’t have much non-coding DNA?

A

Simple organisms such as bacteria

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

Why is it helpful when organisms don’t have much non-coding DNA?

A

It is relatively easy to determine their proteome from the DNA sequence of their genome

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

When can it be useful for organisms not having much non-coding DNA?

A

In medical research and development

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

Why is it harder to translate the genome of complex organisms?

A

They contain large sections of non-coding DNA and they also contain complex regulatory genes (determine when the genes that code for particular proteins should be switched on or off)

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

Why does containing large sections on non-coding DNA make it more difficult to translate the genome of complex organisms into their proteome?

A

Because it’s hard to find the bits that code for proteins among the non-coding and regulatory DNA

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

What were sequencing methods like in the past?

A

Labour-intensive, expensive and could only be done on a small scale

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

What are sequencing methods like now?

A

Automated, cost-effective and can be done on a large scale

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

What does recombinant DNA technology involve?

A

Transferring a fragment of DNA from one organism to another

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

What are organisms that contain transferred DNA known as?

A

Transgenic organisms

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

What are the three ways that DNA fragments can be produced?

A

Using reverse transcriptase, using restriction endonuclease enzymes and by using a gene machine

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

Why is it difficult to obtain a DNA fragment containing the target gene?

A

Most cells only contain two copies of each gene

17
Q

Why is mRNA easier to obtain?

A

Cells contain many mRNA molecules which are complementary to the gene

18
Q

How can mRNA molecules be used?

A

As templates to make lots of DNA

19
Q

What does reverse transcriptase do?

A

Makes DNA from an RNA template

20
Q

What is the DNA called that is produced from an RNA template?

A

cDNA- complementary DNA

21
Q

What do pancreatic cells have?

A

Loads of mRNA molecules complementary to the insulin gene, but only two copies of the gene itself

22
Q

What can reverse transcriptase be used for in pancreatic cells?

A

Making cDNA from the insulin mRNA

23
Q

How does reverse transcriptase make cDNA from the insulin mRNA?

A
  • mRNA is isolated from cells
  • Mixed with free DNA nucleotides and reverse transcriptase
  • The reverse transcriptase uses the mRNA as a template to synthesise a new strand of cDNA
24
Q

What are palindromic sequences of nucleotides?

A

Sequences that consist of antiparallel base pairs

25
Q

What are restriction endonucleases?

A

Enzymes that recognise specific palindromic sequences and cut the DNA at these places

26
Q

Why do different restriction endonucleases cut at different specific recognition sequences?

A

Because the shape of the recognition sequence is complementary to the enzyme’s active site

27
Q

When can you use restriction endonucleases to separate the fragment from the rest of the DNA?

A

If recognition sequences are present at either side of the DNA fragment you want

28
Q

How is the restriction endonuclease used?

A

The DNA sample is incubated with the specific restriction endonuclease which cuts the DNA fragment out via a hydrolysis reaction

29
Q

What can restriction endonucleases leave?

A

Sticky ends

30
Q

What are sticky ends?

A

Small tails of unpaired bases at each end of the fragment

31
Q

What can sticky ends be used for?

A

To bind (anneal) the DNA fragment to another piece of DNA that has sticky ends with complementary sequences

32
Q

How has technology recently been developed?

A

So that fragments of DNA can be synthesised from scratch without the need for a pre-existing DNA template

33
Q

What does the database involved in gene machine contain?

A

The necessary information to produce the DNA fragment

34
Q

How does the gene machine work?

A
  • Sequence required is designed if it doesn’t already exist
  • First nucleotide in the sequence is fixed to some sort of support
  • Nucleotides are added step by step in the correct order, in a cycle of processes the includes adding protecting groups
  • Oligonucleotides are produced
  • Broken off from the support and all the protecting groups are removed
  • Oligonucleotides can the be joined together to make longer DNA fragments
35
Q

What do protecting groups do?

A

Make sure that nucleotides are joined at the right points, to prevent unwanted branching

36
Q

What are oligonucleotides?

A

Short sections of DNA