Molecular Biology and Gel Electrophoresis Flashcards Preview

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Flashcards in Molecular Biology and Gel Electrophoresis Deck (25)
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1
Q

What does the abbreviation DNA stand for?

A

Deoxyribonucleic acid

2
Q

What is a gene?

A

A small section of a chromosome which determines a characteristic or trait

3
Q

What is a genome?

A

The complete set of genetic material in an organism

4
Q

DNA contains 4 different types of bases, what are these bases?

A

Adenine, thymine, cytosine, guanine

5
Q

Explain basic DNA structure in terms of sugars, bases and phosphates

A
  • Nucleotides joined by phosphodiester bonds with sugar phosphate backbone
  • A nitrogenous base attached to a sugar group and a phosphate group makes up a nucleotide
6
Q

Explain the central dogma of molecular biology

A

Involves DNA replication, transcription and translation in order to make proteins

7
Q

Explain “the information for making a new strand of DNA comes from an old strand of DNA”

A

In DNA replication, An old strand of DNA becomes a template to create a new complementary strand

8
Q

Explain transcription

A

Copying a double strand of DNA to a single strand of RNA in the nucleus

9
Q

Explain translation

A

The synthesis of proteins from mRNA that takes place in the ribosomes

10
Q

What is a codon

A

A sequence of three nucleotides which together form a unit of genetic code in DNA or RNA

11
Q

What is meant by genetic code?

A

The genetic information carried by DNA and RNA in living cells

12
Q

What are two differences between RNA polymerases and DNA polymerases?

A
  • RNA polymerase does not need a primer but DNA polymerase does
  • DNA polymerase synthesises DNA for transcription and RNA polymerase synthesises mRNA during transcription
13
Q

Restriction enzyme

A

Enzymes that cut a DNA molecule at a particular location

14
Q

Ligase enzyme

A

Joins DNA strands together

15
Q

Are there any infectious disease causing agents that can not be detected using a PCR type reaction? If so, name one such agent or disease.

A

Yes

16
Q

Ligase enzyme

A

Joins DNA strands together by catalyzing the formation of a phosphodiester bond

17
Q

How can PCR be used in sex determination?

A

Set up a PCR reaction as normal, attach appropriate primers to female DNA and male DNA. The annealing sites of these primers means that the female DNA (including XX chromosomes) will produce 1 band of 488 base pairs, and male DNA (including XY chromosomes) will produce one band of 488 base pairs, and one pair of 340 base pairs

18
Q

What are 3 other applications of PCR?

A
  • Diagnosis of genetic disease
  • Archaeology to identify human or animal remains
  • Research (creating copies of DNA in order to host microbes and discover how they work)
19
Q

Describe the steps of PCR

A

Denaturing: Heating DNA to approx 95 degrees to break the hydrogen bonds between the double strands of DNA and create two single strands
Annealing: Attaching primers to the DNA strands to determine where polymerase will start attaching base pairs at 50-75 degrees
Extension: Polymerase adds base pairs to each strand in order to create two double stranded DNA molecules at 72 degrees

20
Q

Are there any infectious disease causing agents that can not be detected using a PCR type reaction? If so, name one such agent or disease.

A

Yes, PCR is used to amplify DNA, so disease causing agents that do not have DNA (e.g. prions) are hard to detect with PCR

21
Q

Describe an application of electrophoresis

A

Paternity and maternity testing

22
Q

When electrophoresed over a given period of
time, will a small DNA molecule usually migrate
a shorter distance or a further/longer distance
through an agraose gel, compared to a large
DNA molecule?

A

Longer; smaller molecules travel faster through agarose gel than larger molecules

23
Q

True or False? “electrophoresis can separate

molecules based on both size and charge”

A

True

24
Q

What types of molecules can be separated

using Electrophoresis?

A

DNA

25
Q

A certain type of PAGE can be used to
separate denatured proteins. What are
denatured proteins?

A

Denatured proteins are proteins that proteins that have disrupted/destroyed secondary and tertiary structures, and are only left with their primary structure