Complete summary of the course Genetics (AB_1135) from the 1st year of biomedical sciences, VU Amsterdam. This summary contains all information needed for partial exam 1 and 2, and includes all the material from the lectures and the book that was required for this course. This summary was made duri...
Test Bank for Genetics: Analysis and Principles 7th Edition Brooker. All 29 Chapters. Contains MCQ, T/F & Select All That Apply Q&A in 405 Pages
TEST BANK for Genetics: Analysis and Principles 7th Edition. by Robert Brooker. All Chapter 1-29. 405 Pages
All for this textbook (3)
Written for
Vrije Universiteit Amsterdam (VU)
Biomedical Sciences
Genetics (AB_1135)
All documents for this subject (120)
Seller
Follow
SummaryLin
Reviews received
Content preview
Genetics summary (exam 1+2)
1
,Chapter 9 | Molecular structure of DNA and RNA 3
Chapter 12 | Gene transcription and RNA modi cation (processing) 5
Chapter 10 | Chromosome structure 10
Chapter 8 | Chromosome variation 14
Chapter 11 | DNA replication 17
Chapter 3 | Reproduction & chromosome transmission 21
Chapter 13 | Translation of mRNA 23
Chapter 2 | Mendelian inheritance 26
Chapter 4 | Extensions of mendelian inheritance 28
Chapter 5 | Non-mendelian inheritance 31
Chapter 7 | Genetic transfer and mapping in bacteria 34
Chapter 6 | Genetic linkage and mapping in eukaryotes 37
Chapter 14 | Gene regulation in bacteria 39
Chapter 15 | Gene regulation in eukaryotes I: transcriptional and translational
regulation 44
Chapter 16 | Gene regulation in eukaryotes II: epigenetics 49
Chapter 17.3 | RNA interference and miRNAs 53
Chapter 19 | Gene mutation, DNA repair and recombination 54
Chapter 24 | Medical genetics 60
Chapter 25 | Genetic basis of cancer 62
2
fi
, Chapter 9 | Molecular structure of DNA and RNA
Criteria of genetic material
1. Information - must obtain the information necessary to make an entire organism
2. Transmission - must be passed on from parents to o spring
3. Replication - must be copied
> So it can be passed from cell to cell, and parents to o spring
4. Variation - capable of changing
> To account for the known phenotypic variation in each species
> Leads to adaptation + evolution
> Mainly caused by mutation
Discovery of DNA
Friedrich Miescher ‘discovered’ DNA in 1869 by investigating the unknown phosphorus-
containing isolated substance from the nuclei of white blood cells found in waste surgical
bandages -> ‘nuclein’; better understanding of DNA+RNA structure determined that they were
acidic molecules (they release H+ in solution and have net negative charge at neutral pH) ->
‘nucleic acid’
Levels of complexity of nucleic acids
1. Nucleotides - form repeating structural unit of nucleic acids
2. Strand - nucleotides that are linked together in a linear manner
3. Double helix - two strands of DNA (sometimes RNA) interacted with each other
4. Three-dimensional structure of DNA - folding and bending of double helix
Nucleotides in DNA (deoxyribonucleic acid)
- A pentose sugar (2’-deoxyribose)
> Numbered 1’ to 5’
> -OH attached to 3’ C is important for covalent linkages between nucleotides
- Phosphate group (attached to 5’ C via an ester bond)
- A nitrogenous base
> Numbered 1 to 6/9
> Four bases: Adenine, Thymine, Guanine, Cytosine (attached to 1’ C)
> There are more: bases can be chemically modi ed
> In tRNA/mRNA several other modi ed bases
> A-T & G-C connected by hydrogen bonds
Nucleotides in RNA (ribonucleic acid)
- A pentose sugar (ribose)
- Phosphate group (attached to 5’ C)
- A nitrogenous base
- Has an extra OH instead of H
> Four bases: Adenine, Uracil, Guanine, Cytosine (attached to 1’ C)
Di erent bases
- Purine base - contains a double-ring structure
> Adenine + guanine
> Contains 9 C
- Pyrimidine base - contains a single-ring structure
> Thymine + cytosine + uracil
> Contains 6 C
Structure of DNA strand
- Phosphodiester linkage/bonds: phosphate group connects to 2 sugar molecules via 2 ester
bonds -> phosphates + sugars form backbone of strand; bases project from backbone;
backbone is negatively charged due to negative charge of phosphate
> A phosphate connects the 5’ C of one nucleotide to 3’ C of another; all sugar molecules
are oriented in same direction -> directionality (5’ > 3’)
Competition to determine the structure of DNA
- Franklin, Wilkins, Watson & Crick wanted to determine the structure of DNA because
knowledge towards understanding the functioning of genes was needed
- One important method was model building; in early 1950s, Pauling proposed that regions of
proteins can fold into a secondary structure (⍺ helix) -> ball-and-stick model
- Rosalind Franklin used X-ray di raction to study wet bers of DNA
> Pattern was consistent with helical structure
> Diameter of helical structure was too wide to be only single-stranded helix
> Di raction pattern indicated that the helix contains ~10 bp per complete turn
- Charga found that DNA has a biochemical composition in which the %A=%T & %C=%G
- Watson & Crick used previous observations, assuming that DNA is composed of nucleotides
linked together in linear way and that the chemical linkage between 2 nucleotides is always the
same -> built ball-and-stick model with identical base in opposite strand (A-A etc.), but couldn’t
t -> realization that hydrogen bonding of A-T was structurally similar to C-G -> published DNA
structure in ‘Nature’ in 1953 -> got Nobel Prize in physiology/medicine in 1962
> Wilkins (working in same laboratory as Franklin) shared her crucial data with them
Key features of DNA double helix
- Two DNA strands are twisted together around a common axis to form ‘spiral upstairs’ structure
- Double-stranded structure is stabilized by hydrogen-bonded base pairs
> One complete turn contains 10 bp with linear distance of 3,4 nm (0,34 nm per bp)
- A-T & G-C -> relatively constant width
> 3 hydrogen bonds between G-C, but 2 between A-T -> higher proportion of G+C tend
more stability
- Two complementary strands
- One strand 5’ > 3’; other 3’ > 5’ -> antiparallel
- Base stacking provides stability
Grooves = indentations where atoms of the bases are in contact with the water in the surrounding
cellular uid
> (Narrow) minor groove vs (wider) major groove
DNA can form alternative types of double helices
- B-DNA: predominant, right-handed, 10 bp per turn, centrally located bases, hydrogen bonds
between bp are oriented relatively perpendicular to central axis
- Under certain in vitro (and some places, in vivo) conditions, A-/Z-DNA can be formed
- Z-DNA: left-handed, helical backbone zigzags, 12 bp per turn, formation favored by GC-rich
sequences (at high salt concentration) & cytosine methylation (at low salt concentration),
evidence that it may play a role in transcription and determining chromosome structure
- A-DNA: right-handed, 11 bp per turn, occurs under conditions of low humidity, little evidence
that it’s biologically important
> Can be formed under certain in vitro (and some places, in vivo) conditions
4
fi
fffl ff ff fi
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller SummaryLin. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $10.88. You're not tied to anything after your purchase.
