Brainscape's Knowledge GenomeTM

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


See full index

Biology Concepts > DNA > Flashcards

DNA Flashcards

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

Plasmid and what genes it contains

A

small, circular DNA molecules that can contain a variety of genes, including those that confer antibiotic resistance, virulence, and the ability to grow in adverse conditions

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

Rosalind Franklin

A

Rosalind Franklin prepared crystallography from DNA samples
- Her images suggested a double helix with 10 nucleotides/turn
- 2 nm diameter suggested the sugar‐phosphate backbone must
be on outside

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

Crick and Watson

A

used model building, plus physical and
chemical evidence, to solve DNA structure
– Published their results in 1953

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

Structure of DNA

A

Biochemists knew DNA is a polymer of nucleotides
– Each nucleotide consists of deoxyribose, a phosphate group, and a nitrogen‐containing base

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

Four different nucleotides differing only in the bases

A

Purines: adenine (A) and guanine (G)
Pyrimidines: cytosine (C) and thymine (T), holds DNA together

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

DNA vs. RNA nucleotides

A

DNA: Pu. A -> Py. T, Pu. G -> Py. C
RNA: Pu. A -> U (Uracil), Pu. G -> Py. C

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

DNA structure setup

A
  • Bases are on the inside of each strand
  • Sugar‐phosphate groups on outside
  • Chains are antiparallel: run in opposite direction
  • DNA can be found in the nucleus of the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Chargaff’s rule

A

The amount of adenine is always equal to the amount of thymine found in a sample. The amount of cytosine is always equal to the amount of guanine found in a sample

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

DNA strands held together by

A
  • hydrogen bonds between complementary base pairs
  • Van der Waals forces between adjacent bases on same strand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

DNA replication

A

the process by which cells create two identical copies of DNA from a single original DNA molecule

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

Semi conservative

A

each parent strand is a template; new molecules have one old and one new strand

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

2 step DNA replication

A
  • Double helix unwound, making two template strands
  • New nucleotides form complementary base pairs with the template DNA strand and are linked by phosphodiester bonds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

origin of replication and replication fork

A
  • Origin of replication (ori): specific region of DNA that indicates the starting point of replication
  • In E. coli, DNA is unwound, and replication proceeds in both directions, forming two replication forks
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Leading vs. lagging strand and Okazaki fragments

A
  • Leading strand: grows at the 3’ end as the fork opens
  • Lagging strand: the exposed 3’ end gets farther from the fork, and an unreplicated gap form
  • Okazaki fragments: small, discontinuous stretches of new DNA
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

3 repair mechanisms

A
  • Proofreading: DNA polymerase recognizes mismatched pairs
    and removes incorrectly paired bases
  • Mismatch repair: newly replicated DNA is scanned for mistakes by other proteins, and mismatches can be corrected
  • Excision repair: enzymes scan DNA for damaged bases – they’re excised, and DNA polymerase I adds the correct ones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

PCR

A

Polymerase chain reaction (PCR): an automated process that makes multiple copies of short DNA sequences for genetic
manipulation and research

17
Q

2 steps of gene expression

A
  • Transcription: DNA sequence is copied to a complementary RNA sequence
  • Translation: RNA sequence is template for an amino acid sequence
18
Q

Central dogma

A

Proposed by Watson and Crick
DNA -> transcription -> RNA -> translation -> polypeptide

19
Q

Central dogma exceptions

A

Some viruses have RNA instead of DNA
- Most replicate by transcribing a complementary RNA strand, which then makes multiple copies of the viral genome
- Retroviruses undergo reverse transcription: making a DNA copy of an RNA genome

20
Q

Messenger RNA (mRNA)

A

one strand of DNA is copied to a complementary mRNA strand
- In eukaryotes, mRNA moves to the cytoplasm

21
Q

Ribosomal RNA (rRNA)

A

catalyzes peptide bond formation between amino acids to form a polypeptide
- Ribosomes made up of proteins and rRNA

22
Q

Transfer RNA (tRNA)

A

binds specific amino acids and recognizes specific sequences in mRNA
- Recognizes which amino acid should be added next to the growing polypeptide chain

23
Q

Initiation

A

RNA polymerase binds to a DNA promoter sequence
- Promoters: tell enzyme where to start and which strand of DNA to transcribe

24
Q

Transcription factors

A

(eukaryotes): proteins that bind to DNA sequences and RNA polymerase, helping
direct polymerase onto the promote

25
Q

Elongation

A

RNA polymerase unwinds DNA about 10 base pairs at a time; reads template DNA strand in 3’ to 5’ direction

26
Q

Termination

A

where transcription stops; specified by a specific DNA sequence
- For some genes, transcript forms a loop and falls away from the DNA
- For others, a protein binds to the transcript and causes it to detach from the DNA

27
Q

Differences between prokaryotic and eukaryotic gene expression

A

Gene expression is basically the same in prokaryotes and eukaryotes
- Differences in:
- Gene structure
- Location: in eukaryotes, the nucleus separates transcription and translation

28
Q

Intron

A

noncoding regions that are transcribed but then spliced out of pre‐mRNA in the nucleus

29
Q

Exon

A

coding sequences; reach the ribosome

30
Q

What happens during pre-mRNA processing

A

the newly transcribed RNA molecule (pre-mRNA) undergoes modifications including the addition of a 5’ cap, a poly-A tail at the 3’ end, and the removal of non-coding introns through splicing, resulting in a mature mRNA molecule ready for translation into protein; this process occurs primarily in the nucleus of eukaryotic cells

31
Q

genetic code

A

specifies which amino acids will be used to build a protein

32
Q

codon

A

sequence of three bases, each specifying a particular amino acid

33
Q

starting codon

A

initiation signal for translation
- AUG

34
Q

stop codon

A

termination signals
- UAA, UAG, UGA

35
Q

Translation: initiation

A

a charged tRNA and small ribosomal
subunit, both bound to mRNA
- In prokaryotes, rRNA binds to the Shine‐Dalgarno sequence on the mRNA
- In eukaryotes, it binds to the 5’ cap

36
Q

Translation: elongation

A

another charged tRNA enters A site
- Large subunit catalyzes two reactions:
- Bond between tRNA in P site and its amino acid is broken
- Peptide bond forms between that amino acid and the amino acid on the tRNA in the A site

37
Q

Translation: termination

A

translation ends when a stop codon enters the A site

38
Q

Signal sequence

A

short amino acid sequences that guide newly synthesized proteins to their proper location within the cell

Biology Concepts (15 decks)

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