Brainscape's Knowledge GenomeTM

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


See full index

Microbiology > Lesson 2.1 - DNA & Inheritance > Flashcards

Lesson 2.1 - DNA & Inheritance Flashcards

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

Mendel’s work (1900)

A

Chromosomes observed (genotype), but unclear how it was connected to phenotype

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

T.H. Morgan’s Group (1920s)

A

Showed that genes were carried on chromosomes; [20] proteins assumed to be genetic material; fruit flies

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

Who initially performed the transforming principle?

A

Microbiologist Griffith

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

Transforming Principle concluded that…

A

something from heat-killed S cells transformed live R cells; standard assumption was that proteins were responsible

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

Transforming Principle Results (1928)

A

Smooth strains = virulent, rough strains = avirulent

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

Indirect evidence supporting hypothesis that DNA is genetic material

A
  • Using dyes that bind to DNA showed that
    • DNA doubles during “S” phase of cell cycle
    • Diploid (2n) and haploid (n) exists
      • After meiosis, gametes have 1/2 of DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the results of the transforming principle (1944)?

A

R cells were transformed by DNA from heat-killed S cells; example of HGT

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

Who performed transforming principle (1944)?

A

Avery, MacLeod, & McCarty

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

Chargaff’s Rule

A

Purines = Pyrimidines (A = T, G = C)

No organism was 50/50 (e.g. Virus QX174 did not fit data bc single stranded)

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

Rosalind Franklin (1951)

A
  • Analyzed DNA helix with X-ray crystallography
    • Turn every 3.4 nm, Diameter of 2.0 nm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How does X-ray crystallography work?

A

Create 2-D images by defracting rays onto plate

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

How did the 3-D structure of DNA came to be?

A
  • (1953) Models built using following data:
    • Alpha-helix by Franklin & Wilkins
    • Width & no. bases per turn by Franklin & Stokes
    • Purine = Pyrimidine by Chargaff
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Purine Bases

A

Adenine, Guanine

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

Pyrmidine Bases

A

Cytosine, Thymine (DNA), Uracil (RNA)

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

Who won the Nobel Prize in Physioology or Medicine (1962)?

A

Francis Crick, James Watson, & Maurice Wilkins

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

Structure of DNA

A
  • Nitrogenous base
    • Pyrimidine (1-ring)
    • Purines (2-ring)
  • Pentose (5C) deoxyribose
  • Phosphate (PO4) group
  • Major (2.2 nm) & Minor (1.2 nm) groove
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is DNA synthesized?

A
  • Connect sugar of one nucleotide, and phopshate of next
  • Occurs via a phosphodiester link/bond, creating a backphone
    • 5’ of PO4 of incoming nucleotide and 3’ OH
18
Q

What is the Hershey & Chase experiment (1952)?

A
  • Bacteriophage T2 infects E. coli
    • Protein: 35S
    • DNA: 32P
  • Demonstrated that DNA (not protein) transferred, & is genetic material = inheritance
19
Q

DNA sequences are always written…

A

5’ to 3’

20
Q

Deoxyribose sugar structure

A
21
Q

Ribose sugar structure

A
22
Q

3 Hypothesis Models for DNA Replication

A

Semiconservative, Conservative, and Dispersive

23
Q

What is the Meselson - Stahl experiment?

A
  • Each round E.coli in 15N (red) medium was transfered to a 14N (orange) medium, DNA sediments halfway.
  • Supports semiconservative model
24
Q

DNA polymerase can only add nucleotides to the _____ end of a growing DNA strand.

A

free 3’-OH

25
Q

DNA Replication Overview (terms: primase, primer, polymerase, leading and lagging strand, ligase)

A
  • Primase binds to template strand, synthesizes RNA primer
    • Starts with RNA dNTPs, then DNA dNTPs
  • DNA polymerase III synthesizes DNA
  • Leading strand synthesized continously
  • Lagging strand (Okazaki fragments) ligated by ligase
26
Q

Why is the lagging strand looped during DNA synthesis?

A

It allows both strands to be synthesized concurrently by inverting the lagging strand

27
Q

Replisome

A

Proteins that unwind DNA and synthesize new strands

28
Q

Helicase

A

untwists and separates template DNA strands at replication fork

29
Q

Single-strand binding proteins

A

keep unpaired template strands apart during replication

30
Q

Gyrase

A

removes knots or create twists in duplex DNA; cuts ds DNA and passes one through the other

31
Q

Ligase

A

catalyze phophodiester bond formation between new DNA; links Okazaki fragments together

32
Q

Sliding ß-clamp

A

guides DNA polymerase and assists other proteins/enzymes

33
Q

Topoisomerase IV

A

passes one ds DNA through another; cuts ds DNA

34
Q

Bacteria & Archaea divide by…

A
  • Binary Fission
    • Replication from single origin (ori)
      • Plasmids - 1 ori site
    • Replication around cirlce requires primer w/ available 3’-OH
35
Q

E. coli uses _________ to cut one of the chromosomes to separated interlocked chromosomes.

A

Topoisomerase IV

36
Q

DNA Polymerase I (Characteristics, Function)

A
  • 5’ - 3’ Polymerization: +
  • 3’ - 5’ Exonuclease: +
  • 5’ - 3’ Exonuclease: +
  • Function: Joins Okazaki fragments
37
Q

DNA Polymerase II (Characteristics, Function)

A
  • 5’ - 3’ Polymerization: +
  • 3’ - 5’ Exonuclease: +
  • 5’ - 3’ Exonuclease: -
  • Function: Restarted stalled polymerase
38
Q

DNA Polymerase III (Characteristics, Function)

A
  • 5’ - 3’ Polymerization: +
  • 3’ - 5’ Exonuclease: +
  • 5’ - 3’ Exonuclease: -
  • Function: Main replicase
39
Q

DNA Polymerase IV (Characteristics, Function)

A
  • 5’ - 3’ Polymerization: +
  • 3’ - 5’ Exonuclease: -
  • 5’ - 3’ Exonuclease: -
  • Function: Repairs damaged DNA
40
Q

DNA Polymerase V (Characteristics, Function)

A
  • 5’ - 3’ Polymerization: +
  • 3’ - 5’ Exonuclease: -
  • 5’ - 3’ Exonuclease: -
  • Function: Repairs damaged DNA, translesion, DNA synthesis
41
Q

3’ - 5’ Exonuclease function

A
  • Makes cut at misplaced base; proofreading technique; can stop and go backwards
    • Bacterial DNA polymerase I, II, and III
42
Q

Nucleotide Excision Repair System (Cause of damage, solution)

A
  • Damage caused by UV radiation & chemicals
    • e.g. Pyrimidine dimers (covalent bond b/t adjacent pyrimidines)
  • Nuclease cuts out damaged strand
    • Gap filled by DNA polymerase & ligase

Microbiology (17 decks)

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