Brainscape's Knowledge GenomeTM

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


See full index

MCD Nucleic Acids And Gene Expression > 1 Nucleic Acids And Chromosomes > Flashcards

1 Nucleic Acids And Chromosomes Flashcards

1
Q

Q: What joins monomers of nucleic acids? How? What are monomers called?

A

A: monomer= nucleotides

PHOSPHODIESTER LINK

The 3’-OH of sugar of one nucleotide is linked to phosphate group, which in turn is joined to 5’-OH of adjacent sugar on the adjacent nucleotide

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

Q: What is the 3D structure of DNA? (3)

A

A: double helix- 2 chains wrapped around each other -> bases within and 2 sugar phosphate backbones surrounding for support

antiparallel

where each chain has 2 ends- The first nucleotide in a sequence has a free 5’ phosphate and the last nucleotide in the sequence has a free 3’ hydroxyl group (Conventionally, DNA sequences are written from the 5’ end to the 3’ end)

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

Q: What are the components of a nucleoside? nucleotide?

A

A: sugar and base

sugar and base and phosphate

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

Q: What’s the difference between deoxyribose and ribose? What are they both?

A

A: deoxy lacks an oxygen that ribose has

both are sugars

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

Q: Which number carbon of the sugar is attached to the base? By which bond?

A

A: 1 by glycosidic bond

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

Q: What are the 5 bases?

A

A: guanine, adenine, uracil, thymine, cytosine

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

Q: Which bases are purine? What makes them a purine?

A

A: guanine, adenine

double ring structure (larger)

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

Q: Which bases are pyrimidine? What makes them a pyrimidine?

A

A: uracil, thymine, cytosine

single ring structure (smaller)

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

Q: How would you recognise adenine?

A

A: double ring structure, amino group

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

Q: How would you recognise guanine?

A

A: double ring structure, amino group and carbonyl group

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

Q: How would you recognise cytosine?

A

A: single ring structure, amino group, carbonyl group

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

Q: How would you recognise thymine?

A

A: single ring structure, 2 carbonyl group and methyl group

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

Q: How would you recognise uracil?

A

A: single ring structure, 2 carbonyl group

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

Q: In Watson crick base pairing which bases join and by how many hydrogen bonds? Which is more stable?

A

A: C to G by 3 more stable

A to T/U by 2

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

Q: What part of the DNA structure carries genetic info?

A

A: bases

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

Q: What is the method for separating the 2 strands of DNA? When/where does this occur?

A

A: melt/low salt -> melts/denatures

cells when replicating/ induced in labs

17
Q

Q: What is the method for annealing the 2 complementary strands of DNA?

A

A: cooling/high salt -> re anneal/ hybridise

18
Q

Q: What is a karyotype? Why are karyotypes an important diagnostic tool?

A

A: Organised profile of someone’s chromosomes

in some diseases a chromosomes may be comprised of several different chromosomes

19
Q

Q: What does a diploid human cell contain in terms of genetic information? Difference between male and female?

A

A: 22 pairs of autosomal chromosomes (homologous) and a pair of sex chromosomes

XX for female
XY for male

20
Q

Q: Where do the major and minor grooves occur in DNA?

A

A: The major groove occurs where the backbones are far apart, the minor groove occurs where they are close together

21
Q

Q: Compare the genomes of E.coli and Homo Sapiens.

A

A: E.coli has 4.6 x 10^6 base pairs in a single circular double stranded molecule with a length of 1.4mm

around 3 x 10^9 base pairs of DNA divided in chromosomes that each contain a single linear double helical DNA molecule of around 200 x 10^6 base pairs

22
Q

Q: What is a genome?

A

A: the entire DNA coding for an organism

23
Q

Q: When are chromosomes visible? not?

A

A: just before cells divide but not in non dividing cells

24
Q

Q: Describe mitotic chromosomes. DNA appearance?

A

A: highly condensed form of chromosomes

DNA is visible

25
Q

Q: Describe interphase chromosomes. DNA appearance?

A

A: extended form of chromosomes (non dividing= loose)

less compact that mitotic form of chromosomes

DNA is not visible

26
Q

Q: Describe the packaging of eukaryotic DNA. Include nucleosomes.

A

A: DNA is tightly packed forming a complex with proteins - the complex is called CHROMATIN

NUCLEOSOMES - lowest level of packing - consists of DNA wrapped around 8 histones with linker DNA between histones

1 histone between the nucleosomes

27
Q

Q: Are histones positively or negatively charged? What does this result in?

A

A: Histones are positively charged so interact closely with the negatively charged sugar phosphate backbone

28
Q

Q: Around how many base pairs of DNA are there per nucleosome?

A

A: 200

29
Q

Q: What fold condensing of DNA do nucleosomes cause?

A

A: 7

30
Q

Q: How is the chain of nucleosomes further packed? What fold condensing of DNA does this cause

A

A: FIBER - the nucleosomes are further packed to generate a more compact structure with around 40 fold condensing of DNA.

31
Q

Q: What does chromatin contain?

A

A: DNA and proteins

MCD Nucleic Acids And Gene Expression (8 decks)

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