Unit 3 - Global Structure of Chromosomes Flashcards
One complete set of your chromosomes
Genome
______ sizes can differ among different related organisms
Genome
One of the smallest viruses that has 4000 nucleotides
Macrophage MS2
Causative agent of lyme disease
Linear DNA with 910000 nucleotides or 910 kb (kilobase 10^3)
Borrelia burgdorferi
has 4600 kb
Escherichia coli
has 13 mb (megabase 10^6)
Saccharomyces cerevisiae
it is the raw material of inheritance and ultimately influences all aspects of the structure and functioning of the human body.
DEOXYRIBONUCLEIC ACID (DNA)
A single molecule of _______, along with associated proteins, comprises a chromosome.
DEOXYRIBONUCLEIC ACID (DNA)
Chromosomes are located in the nuclei of all human cells with the exemption of your mature RBCs
DEOXYRIBONUCLEIC ACID (DNA)
Each human cell contains 23 different pairs of
chromosomes that codes for protein molecules
DEOXYRIBONUCLEIC ACID (DNA)
Functional units of genetic information
GENE
Linear sequences of nitrogen bases
Gene
he was the first to provide evidence linking inherited disease and protein, particularly enzymes
ARCHIBALD GARROD
he discovered of inborn error of metabolism
ARCHIBALD GARROD
He noted that individuals with inborn error of metabolism lack certain enzymes
ARCHIBALD GARROD
Swiss physician and biochemist
He isolated the nuclei from WBC
FRIEDRICH MEISCHER
unusual acidic substance containing nitrogen and
phosphorus
Material that resides in cell nuclei
Also known as nucleic acids
NUCLEIN
Friedrich Meischer termed it nuclein on ______
1871
they hypothesized that a nucleic acid might be the “transforming principle”
The DNA passed from type S bacteria to type R bacteria, therefore, type R bacteria have the ability to manufacture its polysaccharide capsule that may cause the infection
OSWALD AVERY, COLIN MACLEOD and MACLYN
MCCARTY
Lacks homogentisic acid oxidase
ALKAPTONURIA
Kung wala itong homogentisic acid oxidase, magkakaroon ng accumulation ng homogentisic acid
ALKAPTONURIA
When homogentisic acid is exposed to _____, your urine will turn into color ______
air; black
Kapag merong homogentisic acid, it will turn into your _________
maleylacetoacetic acid
Other inborn errors discovered by Garrod
Albinism
Cystinuria
He discovered in 1929 a similar sugar— deoxyribose (DNA) —in other nucleic acids.
PHOEBUS LEVENE
he identified the 5-carbon sugar ribose (RNA) as part
of some nucleic acids,
PHOEBUS LEVENE
he discovered that the three parts of a nucleic acid are present in equal proportions
1. Sugar
2. Nitrogen base
3. Phosphorus group
Ribose and deoxyribose is the major chemical distinction between your DNA and RNA
PHOEBUS LEVENE
he noticed that mice with a certain form of pneumonia harbored one of two types of Diplococcus pneumoniae
FREDERICK GRIFFITH
Dismantle protein pero namatay pa rin yung daga
PROTEASE
Dismantle DNA
prevents the transformation, so nabuhay yung daga
Narealize nila na yung DNA pala ang cause kung bakit nagdedevelop ng pneumonia
DNase
two types of diplococcus pneumoniae
Type R
Type S
When it is injected sa mice, it will not develop pneumonia
Type R
Develop pneumonia
Namatay yung daga as you can see huhu
Merong polysaccharide capsule
Type S
ADDITIONAL NOTES IN TYPES OF DIPLOCOCCUS PNEUMONIAE
- napansin nila na pag heat killed yung bacteria eh
walang nadedevelop na pneumonia pero hindi nila
alam na may naiwang intact DNA - minix nila yung type R and type S tapos namatay yung
daga, kasi may naiwan pa rin na intact DNA
he showed that DNA in several species contains equal amounts of the bases adenine and thymine, and equal amounts of the bases guanine and cytosine
Yung mga may complementary pairs
lang ang equal amount
ERWIN CHARGAFF
Nitrogen bases are not present in equal amounts
Chargaff rule
they bombarded DNA with X rays using a technique called X-ray diffraction, then deduced the overall structure of the molecule from the patterns in which the X rays were deflected
MAURICE WILKINS & ROSALIND FRANKLIN
She distinguished two forms of DNA—a dry, crystalline “A” form, which had been well-studied, and the wetter type seen in cells, the “B” form.
The molecule was a sleek helix, and revealed the
position of the phosphates
ROSALIND FRANKLIN
Who showed Rosalind Franklin’s photo 51 to James Watson?
Maurice Wikins
Clear image of DNA
Photo 51 (May 1952)
Who discovered the structure of DNA
Rosalind Franklin,
James Watson, Francis Crick, Maurice Wilkins
They received the Nobel prize for the DNA structure discovery
James Watson, Francis Crick, Maurice Wilkins
Ginamit nila yung image (photo 51) and yung experiments ni Wilkins and Franklin para magkaroon ng clearer image / structure ng DNA
Deciphered the structure of DNA with the use of series of experiments made by Wilkins and Franklin
JAMES WATSON & FRANCIS CRICK
He isolated nuclein in white blood cell nuclei
Friedrich Miescher
When did Friedrich Miescher isolate nuclein in white blood cell nuclei?
1869
He transferred killing ability between types of bacteria
Frederick Griffith
When did Frederick Griffith transfer killing ability between types of bacteria?
1928
They discovered that DNA transmits killing ability in bacteria
Oswald Avery, Colin MacLeod & Maclyn McCarty
When did Oswald Avery, Colin MacLeod & Maclyn McCarty discover that DNA transmits killing ability in bacteria?
1940s
They determined that the part of a virus that infects and replicates is its nucleic acid and not its protein
Alfred Hershey and Martha Chase
When did Alfred Hershey and Martha Chase determine that the part of a virus that infects and replicates is its nucleic acid and not its protein?
1950
They discovered DNA components, proportions and positions
Phoebus Levene, Erwin Chargaff, Maurice Wilkins and Rosalind Franklin
When did Phoebus Levene. Erwin Chargaff, Maurice Wilkins and Rosalind Franklin discover DNA components, proportions and positions?
1909-early 1950s
They elucidated DNA’s three-dimensional structure
James Watson and Francis Crick
When did James Watson and Francos Crick elucidate DNA’s three-dimensional structure?
1953
He had his genome sequenced
James Watson
James Watson had his genome sequenced. What year?
2008
A single building block of DNA.
NUCLEOTIDE
Composition of nucleotide
Deoxyribose sugar
Phosphate group
Nitrogen bases
phosphorous atom bonded with 4 oxygen
atoms
Phosphate group
purines and pyrimidines
Nitrogen bases
Adenine and Guanine; it has 2 rings structure
Purines
Thymine and Cytosine; single ring structure
Pyrimidines
the information-containing parts of DNA because they form sequences.
Nitrogen bases
Genetic information is determined by the order of bases
Nitrogen bases
Nucleotides join into long chains when chemical bonds form between the deoxyribose sugars and the phosphates
Sugar-phosphate backbone
The opposing orientation of the two nucleotide chains in a DNA molecule is called
Two chains of nucleotides align head-to-toe.
antiparallelism
One chain/ one strand of the double helix runs from 5’ or “5 prime” to 3’ or “3 prime” and the other chain runs from 3’ to 5’
It will be evident if we indicate numbers.
Arise from the orientation of the deoxyribose sugars
antiparallelism
Dotted lines that hold the nitrogenous bases of one strand to the nitrogenous bases of the second strand.
Nitrogenous bases are bonded with _______
Hydrogen bonds
DNA forms a double helix when the antiparallel, base paired strands twist about one another in a regular fashion.
The DNA in a single diploid cell or single human diploid cell, stretched out, would be approximately 2 meters in length.
- It needs to be condensed so that it will fit on the nucleus
- With the use of proteins like histones, macocondense natin siya.
DNA ORGANIZATION
DNA coils around proteins called _______, forming a beads-on-a-string-like structure
HISTONES
Types of Histones (8)
2 molecules of H2A
2 molecules of H2B
2 molecules of H3
2 molecules of H4
8 histones will form protein core that is also known as _______
-The double-helix DNA winds twice around this _______ to form a 10 nanometer nucleosome/ beads-on-a string-like structure
OCTAMER
The bead part is called a ________
It is linked/ pulled together by a linker segment
- Linker segment- histone H1
DNA —> coiling of DNA —> Proteins (histones) will form nucleosome —-> nucleosome with further coiling will form 30 nm solenoid with further coiling and condensation of solenoid it will form highly compacted chromosome
- Chromosome reaches greatest extent of
condensation that will occur during
mitotic metaphase
NUCLEOSOME
The chromosome substance is called ______,
which means “colored body”
CHROMATIN
COMPOSITION OF HISTONES
Aralin niyo yung table HAHAHA
TYPES OF DNA
Unique sequence DNA
Highly repetitive DNA
Middle repetitive DNA
It contains single copy
Examples are genes that owed for protein
Most common type of DNA
It composes 75% of the human genome
Unique sequence DNA
Occur for more than 105 copies
Seen in telomeres
Highly repetitive DNA
102 to 104 copies
Seen in centromeres
Middle repetitive DNA
DIFFERENT AREAS OF CHROMOSOMES
CENTROMERES
TELOMERES
NUCLEOLAR ORGANIZER REGIONS (NOR)
CHROMATIN
EUCHROMATIN
HETEROCHROMATIN
constriction visible on metaphase chromosomes where the two sister chromatids are joined together.
Site of chromosomes
Attachment portion/ point/ site for spindle microtubules during cell division
Interaction with the mitotic spindle during cell division occurs at the this region
CENTROMERES
protein complex in
centromeres
Kinetochore
Types of Centromeres
Metacentric
Acrocentric
Submetacentric
Acentric
Dicentric
Near one end
Acrocentric
The centromere is located near the middle
Metacentric
Between the middle and end
Submetacentric
Lacks centromere
Acentric
Two centromere
Dicentric
physical ends of chromosomes
protective caps to chromosome ends
Telomeres
prevent and end fusion of chromosomes
Prevent DNA degradation
Telomeres
contain tandem repeats of the nitrogenous base sequence TTA GGG at the chromosome ends
Maraming G - it is sometimes called G rich tail
Telomeres
Telomere length gradually _______ with the aging process and with ________ numbers of cell divisions in culture
decreases; increased
decreased length of telomeres are caused of the _________________
Tumor suppressors mechanism
Cells that have defective or unstable telomerase will exhibit ___________ of chromosome that will lead to ___________________
shortening; chromosome instability and cell death
It is where the nucleolar form
Site of the ribosomal RNA genes
Production of rRNA
Nucleolar Organizer Regions (NOR)
Chromatin COMPOSITION
30% of histone proteins
30% of DNA binding proteins
30% of DNA
10% of RNA
loosely organized, extended, and uncoiled.
Active chromatin
contains active, early replicating genes, and stains lightly with GTG banding techniques
Euchromatin
GTG banding techniques
GTG banding by Giemsa with Trypsin
Genetically inactive, late replicating during the synthesis (S) phase of mitosis, and are highly contracted.
Heterochromatin
Types of Heterochromatin
CONSTITUTIVE Heterochromatin
FACULTATIVE Heterochromatin
Consists of simple repeats of nitrogenous bases that are generally located around the centromeres of all chromosomes and at the distal end of the Y chromosome.
Constitutive Heterochromatin
Constantly inactive
The only established function of _____ is the regulation of crossing over.
Constitutive Heterochromatin
important in cell division, exchange of gene from one’s chromatids to another
Crossing over
Regulates gene function
Silently inactive;
SILENCED
Facultative Heterochromatin
One X chromosome of female is randomly inactivated
This inactivated X chromosome is condensed in interphase and replicates during S-phase
Facultative Heterochromatin
