Brainscape's Knowledge GenomeTM

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


See full index

MCAT Biology and Biochemistry > Biochemistry Chapter 6: DNA and Biotechnology > Flashcards

Biochemistry Chapter 6: DNA and Biotechnology Flashcards

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

What do nucleosides contain?

A

5-C sugar bound to a nitrogenous base

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

What is a nucleotide?

A

A nucleoside with 1 to three phosphate groups added.

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

Difference in nucleotides between DNA and RNA?

A

Deoxyribose vs. Ribose

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

What are the 5 types of nucleotides?

A 
Adenine
Cytosine
Guanine 
Thymine
Uracil
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How is DNA organized?

A
  • read 5’ to 3’
  • antiparallel strands
  • purines pair with pyrimidines (A-T(U)) (G-C)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How many bonds between A and T, G and C?

A

A - T = 2 bonds

G - T = 3 bonds

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

What does it mean that purines and pyrimidines are aromatic heterocycles?

A

cyclic, planar and conjugated

contain 4n + 2 pi electrons where n is any integer. At least two different elements in the ring

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

What is Chargaff’s rule?

A

purines and pyrimidines are equal in number in a DNA molecule and that because of base-pairing, the amount of A = T and G = C

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

What type of helix is most DNA?

A

B-DNA - forming a right hand helix. When high G-C content or high salt concentration, may see zigzag Z-DNA

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

What can cause denaturation of DNA?

A

Heat alkaline pH, chemicals

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

How many chromosomes are there?

A

46 - 44 autosomes and 2 sex chromosomes

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

What is DNA stored in?

A

Histone proteins (H2A, H2B, H3 and H4) – histones make nucleosomes, make up chromatin

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

Heterochromatin

A

dense, transcriptionally silent, appears dark

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

Euchromatin

A

less dense and transcriptionally active

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

Telomeres

A

contain high GC content to prevent unraveling - shortened during replication - prevent against molecular aging

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

Centromeres

A

Located in the middle of chromosomes and hold sister chromatids together until they are separated during anaphase in mitosis.

17
Q

What is the replisome?

A

a set of specialized proteins that assist the DNA polymerases

18
Q

How are single strands kept from reannealling?

A

single-stranded DNA-binding proteins

19
Q

What creates nicks in the DNA to help alleviate supercoiling tension?

A

DNA topoisomerase II (DNA gyrase)

20
Q

What puts down a small RNA primer?

A

primase

21
Q

What does DNA polymerase III (pro) or alpha and delta (euk) do?

A

synthesizes a new strand of DNA - read 3’ to 5’ and write 5’ to 3’

22
Q

What removes DNA primers?

A

DNA polymerase I (prok) or RNase H (euk)

23
Q

What does ligase do?

A

fuses DNA strands together

24
Q

What do oncogenes develop from?

A

mutations of protooncogenes and promote cell cycling. May lead to cancer.

25
Q

What are tumor suppressor genes?

A

code for proteins that reduce cell cycling or promote repair

26
Q

What is a mismatch repair?

A

Occurs during the G2 phase using the genes MSH2 and MLH1

27
Q

What is a nucleotide excision repair?

A

fixes helix-deforming lesions of DNA, via a cut and patch process that requires and excision exonuclease.

28
Q

What is a base excision repair?

A

fixes nondeforming lesions of the DNA helix by removing the base, leaving a apurinic/apyrimidinic site. An AP endonuclease removes the damaged sequence, which can be filled in with the correct bases.

29
Q

What is recombiant DNA?

A

DNA composed of nucleotides from 2 different sources.

30
Q

What is cloning?

A

introduces a fragment of DNA into a vector plasmid. A restriction enzyme cuts the plasmid and DNA, leaving sticky ends. Once the fragment binds, it can be introduced into a bacteria cell.

31
Q

Vectors contain:

A

an origin of replication, fragment of interest, and at least 1 gene for antibiotic resistance

32
Q

What are cDNA libraries?

A

contain smaller fragments of DNA and only include the exons of genes expressed by the sample tissue. They can be used to make recombinant proteins or for gene therapy.

33
Q

What is PCR?

A

an automated process by which millions of copies of a DNA sequence can be created from a very small sample by hybridization.

34
Q

How can DNA molecules be separated?

A

agarose gel electrophoresis

35
Q

Southern blotting

A

Can be used to detect the presence and quantity of various DNA strands in a sample. After electrophoresis, the sample is transferred to a membrane that can be probed.

36
Q

How do you do DNA sequencing?

A

uses dideoxyribonucleotides to terminate the DNA strand because they lack the 3’ OH group.

37
Q

What is gene therapy?

A

method of curing genetic deficiencies by introducing a functional gene with a viral vector

38
Q

Chimera

A

contain cells from two different lineages

39
Q

What is a knockout?

A

deleting a gene of interest

MCAT Biology and Biochemistry (24 decks)

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