Term
| What are the stages of the Cell Cycle? What is happening at each stage? |
|
Definition
Stages: G1 (Growth), S (Synthesis), G2 (Growth), M (Mitotic)
G1: Growth and normal metabolic processes, S: DNA replication, G2: Growth and preparation for mitosis, M: Mitosis |
|
|
Term
| what role to cyclin-dependent kinases play in regulating the cell cycle? |
|
Definition
| Kinase binds to cyclin and then phosphorylates the proteins needed for the next part of the cell cycle |
|
|
Term
| what is apoptosis? how does it differ from necrosis? |
|
Definition
| Programmed cell death. Necrosis is death of a cell caused by outside factors such as toxins, lack of nutrients or oxygen, or another pathological reason |
|
|
Term
| What are the stages of mitosis? Describe the stages simply. |
|
Definition
| Prophase, Metaphase, Anaphase, Telophase. |
|
|
Term
What role does the cytoskeleton play in mitosis?
** |
|
Definition
|
|
Term
| What is cytokinesis? When does it not happen? |
|
Definition
| Division of the cell cytoplasm, occuring at the end of mitosis. Does not occur in cells with more than one nucleus (muscle cells). |
|
|
Term
| With regards to chromosome number, how do somatic cells differ from gametes? |
|
Definition
Somatic cells are the cells in your body. In humans they have 46 chromosomes. Diploid cells.
Gametes are sex cells. They have 23 chromosomes. Haploid cells. |
|
|
Term
| What processes produce somatic cells, what process produces gametes? |
|
Definition
| Mitosis produces somatic cells and meiosis produces gametes |
|
|
Term
| Describe the Prophase and Metaphase I steps in Meiosis |
|
Definition
Differ from Mitosis.
In Meiosis, PROPHASE I:
-these homologous pairs of chromos line up to each other; this structure will now consist of 4 Chromatids /\/\ (2 chromos XX XX) and the entire grouping is known as a TETRAD; XX XX
CROSSOVER-the inner 2 chromatids of the TETRAD may break & rejoin to each other at various locations, thus exchanging genetic material between homologous chromos.
In Meiosis, METAPHASE I:
-a second difference occurs which also helps to redistribute genetic material;
INDEPENDENT ASSORTMENT -Homologous chromos line up, they arrange themselves on either side of the Metaphase plate, Independent of the other pairs(some of Dads chromos on right side while some are on the left, same for mom). When cell divides each New Cell produced will contain both mom & dad Genes. Again the process has increased the potential # of genetic possibilities. |
|
|
Term
| What is the difference between homologous chromosomes and sister chromosomes? |
|
Definition
chromosomes containing (nonidentical) information from each parent for the same trait vs. chromosomes from singular parent which share identical information
think homologous is same type and sister is identical |
|
|
Term
| What is a bivalent? Why are they formed? |
|
Definition
| homologous chromosomes line up side by side. formed so that the recombination of DNA can occur and create greater variation in potential offspring |
|
|
Term
| What results from Meiosis I? Meiosis II? |
|
Definition
| Meiosis I takes diploid cells to haploid cells. Meiosis II separates the sister chromosomes. End with 4 haploid cells |
|
|
Term
| How does chromosome number vary amongst species? |
|
Definition
| Genome size increases with complexity |
|
|
Term
| How do mutations alter chromosome structure? |
|
Definition
Euploid- chromosome # that is viewed as normal
Diploid- 2 sets is normal
Polyploid- 3 or more sets of chromosomes
Aneuploidy- Alteration # of particular chromosomes, total # not exact multiple of set
Trisomic- Normal 2 sets of chromosomes plus a third
Monosomic- Missing one of normal copies of a chromosome |
|
|
Term
| How are sperm and eggs formed? How do these processes differ? |
|
Definition
| Meiosis I and II. In spermatogenesis results in 4 gametes. In oogenesis results in 1 functional gamete |
|
|
Term
| What are the common chromosomal mutations? |
|
Definition
| deletions, duplications, inversions, translocations, nondisjunction |
|
|
Term
| what are the aneuploid conditions in humans? |
|
Definition
Autosomal: Down (Trisomy 21), Edward (Trisomy 18), Patau (Trisomy 13)
Chromosomal: Klinefelter (XXY), Jacobs (XYY), Triple X (XXX), Turner (XO) |
|
|
Term
|
Definition
| an organisms observable characteristics. The physical, viewable expression of genetics |
|
|
Term
|
Definition
| an organisms genetic makeup. It's genetic traits. |
|
|
Term
|
Definition
| One of a number of different forms of a gene |
|
|
Term
|
Definition
| Having received the same type of gene from both parents. ex: both parents gave dominant chromosomes |
|
|
Term
|
Definition
| Having received different types of a gene from each parent. ex one parent gave dominant and the other gave recessive |
|
|
Term
|
Definition
| A gene whose expression eclipses recessive genes |
|
|
Term
|
Definition
| A gene whose physical expression can be eclipsed if paired with a dominant gene |
|
|
Term
| Who is Gregor Mendel and what did he do? |
|
Definition
Father of genetics.
Found:
-Traits stay segregated not blended
-Variations in appearance are due to alternate versions of heritable factors
-Organisms receive 2 versions of each factor, one factor from each parent
-Recessive and Dominant genes |
|
|
Term
| What does it mean to be true breeding? |
|
Definition
| When two organisms of the same phenotype breed in order to produce offspring of the same phenotype |
|
|
Term
| What does it mean to have linked genes? |
|
Definition
| Genes that are inherited together with the other gene(s) as they are located on the same chromosome. |
|
|
Term
| What is the rule of multiplication and the rule of addition? When would you use each? |
|
Definition
x: The probability that 2 events will occur simultaneously is the product of their individual probabilities
probability of a white flowered plant from 2 heterozygous purple plants is 1/2 x 1/2= 1/4
+: the probability that 2 events can occur in 2 or more independent ways
In the above example, what is the probability that the offspring will be heterozygous 1/4 + 1/4 = 1/2 |
|
|
Term
| What is a test cross? What information can it give you? |
|
Definition
To determine the GENOTYPE of a parent with the dominant PHENOTYPE:
-Cross parent with a homozygous recessive individual
Yields:
If Homozygous, all offspring are dominant phenotype
If heterozygous, 1/2 of offspring will have recessive phenotype |
|
|
Term
| Describe the major findings of Griffith |
|
Definition
Bacterial Transformation experiment: a biochemical genetic material exists
(Using Streptococcus pneumoniae) |
|
|
Term
| Describe the major findings of Avery, MacLeod and McCarty |
|
Definition
DNA is the genetic material
Only purified DNA from type S could transform type R
Purified DNA might still contain traces of contamination that may be the transforming principle
Added DNase, RNase and proteases
RNase and protease had no effect
With DNase no transformation
DNA is the genetic material |
|
|
Term
| Describe the major findings of Hershey and Chase |
|
Definition
studying T2 virus infecting Escherichia coli
Bacteriophage or phage
Phage coat made entirely of protein
DNA found inside capsid |
|
|
Term
| Describe the major findings of Watson, Crick, and Franklin |
|
Definition
| DNA is a double helix (crystallography) |
|
|
Term
| How is DNA organized into a gene and a chromosome? |
|
Definition
|
|
Term
| How do the base pairs of DNA match? |
|
Definition
|
|
Term
|
Definition
In the leading strand
DNA synthesized in as one long continuous molecule
DNA primase makes one RNA primer
DNA polymerase III attaches nucleotides in a 5’ to 3’ direction as it slides forward
In the lagging strand
DNA synthesized 5’ to 3’ but as Okazaki fragments |
|
|
Term
| How does DNA Polymerase III work? What are its limitations? |
|
Definition
Covalently links nucleotides
DNA polymerase unable to begin DNA synthesis on a bare template strand (Needs a primer)
DNA primase must make a short RNA primer
RNA primer will be removed and replaced with DNA later
DNA polymerase can only work 5’ to 3' |
|
|
Term
| How is DNA arranged in a nucleosome? |
|
Definition
|
|
Term
| What are the enzymes necessary for DNA replication? What does each do? |
|
Definition
DNA Polymerase - Elongates a new DNA strand at a replication fork. Adds nucleotides one by one to the new and growing DNA strand.
DNA ligase - Joins sugar-phosphates of Okazaki fragments. Okazaki fragments are found on the lagging strand.
Primase - Starts an RNA chain from scratch that will eventually be replaced by DNA nucleotides (remember nucleotides come from DNA polymerase).
Helicase - Untwists the double helix at replication forks to make two parental strands available as template strands.
Topoisomerase - Relieves strain of ahead of the replication fork due to untwisting of the double helix.
These five enzymes are the most basic needed for DNA replication as has been described above. As I said earlier there are many more enzymes that can be utilized depending on species. Also, if you go more in depth and want to know about proofreading and repairing DNA, even MORE enzymes crop up. I would suggest reading your text book to get a better idea of what is going on. For instance, if we are talking about replication of the lagging strand of DNA, the order of enzymes being put to work would be as follows:
Helicase ---> Topoisomerase ---> Primase ---> DNA polymerase ---> DNA ligase |
|
|
Term
| What is telomerase and what is its significance? |
|
Definition
| This enzyme attaches many copies of DNA repeat sequences to the end of chromosomes because DNA polymerase cannot copy the tip of the 3' DNA strand. |
|
|
Term
|
Definition
a segment of DNA that is functional. Specifies the arrangement of amino acids that will make a functional product.
"Link between genotype and phenotype"
"One gene, one polypeptide" |
|
|
Term
| How does RNA compare to DNA? How are the bases and base-pairing similar and different? |
|
Definition
|
|
Term
| Describe the steps of Transcription |
|
Definition
1) Initiation: RNA synthesis.
RNA polymerase binds at promoter region of the gene
Sigma factor binds to RNA polymerase and promoter
DNA strands are separated to form 'open complex'
2) Elongation: RNA polymerase travels along the template strand to make the mRNA using free nucleosomes
Opposite strand to template is 'coding strand'
A/U, G/C rule
3) Termination: RNA polymerase continues on template strand until a termination signal is encountered |
|
|
Term
| What is the promotor? What are transcription factors? ** |
|
Definition
| Promoter comes before exons and introns |
|
|
Term
| What is required for Eukaryotic transcription? |
|
Definition
| RNA polymerase I, II, and III. |
|
|
Term
| What is rRNA for? Where does it travel? |
|
Definition
| Used for making ribosomes. synthesized in nucleolus. Proteins made in cytosol and imported to nucleus. |
|
|
Term
| What is a codon? What is the start codon? |
|
Definition
| A 3 base sequence. AUG (on mRNA) |
|
|
Term
| Describe the detailed steps in translation: a site, p-site, e-site, name of reaction that forms the peptide bonds |
|
Definition
1) Initiation: initiation of protein synthesis
Requires initiation factors and energy (GTP)
small subunit of ribosome binds to mRNA and moves until stop codon is reached.
2) Elongation: elongation of the protein
Aminoacyl tRNA brings a new amino acid to A site
Elongation factors hydrolyze GTP to provide energy to bind tRNA to A site
Peptide bond forms between amino acid at the A site and the growing polypeptide chain
the polypeptide is removed from the tRNA in the P site and transferred to the amino acid at the A site
rRNA catalyzes peptide bond formation (ribosome is ribosome!)
Movement of ribosome towards 3' end of the mRNA by one codon
Shifts tRNAs at P and A sites to the E and P sites
3) Termination:
Stop codon found at the A site recognized by release factors |
|
|
Term
|
Definition
| Aminoacyl catalyzes attachment of amino acids |
|
|
Term
| How is transcription regulated in eukaryotes? |
|
Definition
| Repressor and Activator Proteins |
|
|
Term
| What does it mean to have combinatorial control? |
|
Definition
| Activator or Suppressor proteins may stimulate or inhibit (respectively) the ability of RNA polymerase to initiate transcription. |
|
|
Term
| What is the role of the core promoter? |
|
Definition
| Transcriptional start site+TATA box: |
|
|
Term
| What is the role of the TATA box? |
|
Definition
| Determines precise starting point for transcription. Is 25 base pairs "up stream" from starting site |
|
|
Term
| What is the role of regulatory elements? |
|
Definition
|
|
Term
| What is the role of the mediator? |
|
Definition
| Mediates interactions of activators and repressors. Regulates the rate of transcription of a gene. |
|
|
Term
| What is the role of the Activator? |
|
Definition
| Bind to enhancers. necessary to promote the loosening up of the region of the chromosome where the gene being transcripted is located. Akin to unzipping the chromosome so that the RNA Polymerase can access the gene. |
|
|
Term
| What is the role of the Repressor? |
|
Definition
| Bind to silencers. proteins (usually DNA methylation) that inhibit transcription by preventing Activator proteins or by recruiting proteins that make the DNA more compact |
|
|
Term
| How is chromatin structure altered to regulate transcription? |
|
Definition
| Compacted to Loosened to either inhibit or activate gene transcription |
|
|
Term
| What are microRNA’s, how do they function? |
|
Definition
| small RNA molecules that silence the expression of pre-existing mRNAs |
|
|
Term
| What are some examples of translational and post-translational control? |
|
Definition
Translational: Masking of mRNA, Life of mRNA
Post:Activation of Protein product, degradation of protein product |
|
|
Term
|
Definition
| A heritable change in the genetic material |
|
|
Term
| How do gene mutations occur? |
|
Definition
Spontaneous: Errors in DNA replication, Toxic Metabolic products, Changes in nucleotide structure, Transposons.
Induces: Chemical and Physical agents (ex. cigarettes or UV- these cause cancer) |
|
|
Term
What are the different types of gene mutations? What are the
differences between them? |
|
Definition
Base substitutions:
Silent- causes no change
Missense- changes one amino acid
Nonsense- changes to a stop codon
Addition or Deletion of a single base:
Frameshift- produces a different amino acid sequence |
|
|
Term
| How do somatic cells and germline cells differ? How would mutations in these cells affect the individual? The offspring of the individual? |
|
Definition
|
|
Term
| What is cancer? What causes cancer? |
|
Definition
| Changes in the body's own cells that cause uncontrolled cell growth. It is caused by a combination of genetics, lifestyle, and environment. |
|
|
Term
| What role do oncogenes play in the formation of cancer? |
|
Definition
| the first promotes cell growth and alteration causes uncontrolled cell growth. Improper activation of signal transduction (Ras Pathway). overexpression of transcription factor. Mutation of cell cycle regulator. |
|
|
Term
What are checkpoint proteins and what is their role in the cell
cycle and cancer? |
|
Definition
| Checkpoint proteins check to make sure the cell is ready to move to the next stage of cell growth and division. If the cell is abnormal it does not move to the next stage. In cancer this is disrupted, allowing mutated cells to continue to grow without being stopped by checkpoint factors. |
|
|
Term
| What are the hallmarks of cancer? (10) |
|
Definition
1) Self sufficiency of growth signals
2) Insensitivity to anti-growth signals
3) Tissue invasion and Metastasis
4) Limitless Replicative Potential
5) Sustained Angiogenesis
6) Evading Apoptosis
7) Uses Unusual Metabolic Pathways
8) Evade Immune System
9) Higher than usual mutation rates
10) Cause Inflammation in Tissue |
|
|
Term
| Describe the significance of p53. When does it not work? What happens when it doesn't work? |
|
Definition
| Recognizes when too many mutations have occurred in a piece of DNA and subsequently triggers cell death. Activates cell repair, cell arrest, and apoptosis. HPV involves loss of this protein. When it doesn't work the cell does not respond to triggers for cell death, cell cycle checkpoints become invalid and continue through M phase, Lack of checkpoints results in accumulation of mutations. |
|
|
Term
| What are the current tools used to screen cancer? |
|
Definition
Physicals
Chemical Lab tests: Pap, HPV, Prostate specific antigen (PSA)
Imaging: Mammography, colonoscopy, MRI, CT, Ultrasound
Genetic test: genetic microarratys |
|
|
Term
| What are molecular and immuno-therapeutic treatments for cancer, why are they “better” than more traditional therapies? |
|
Definition
| current therapies are not selective of cancer cells and have a lot of side effects |
|
|
Term
|
Definition
To produce large amounts of DNA of a specific gene
Expressing the cloned gene to produce the encoded protein |
|
|
Term
|
Definition
1) Vector DNA acts as a carrier for the DNA segment to be cloned
When a vector is introduced into a living cell, it can replicate making many copies
Common vectors are plasmid or viral
Also need the gene of interest from chromosomal DNA
2) Insert chromosomal DNA into vector
Cut DNA using restriction enzymes or restriction endonucleases
3) Vector carries a selectable marker
Presence of antibiotics selects for cells expressing ampR gene – contains plasmid
ampR gene codes for b-lactamase that degrades ampicillin, which normally kills bacteria |
|
|
Term
| What is the role of vectors and viruses? |
|
Definition
| Vectors and viruses act as plasmids and can carry segments of DNA into another cell where the DNA can recombine with the cell's DNA |
|
|
Term
| How is the DNA cut and inserted into the vector? |
|
Definition
restriction enzymes and restriction endonucleases
restriction enzyme opens up vector and cuts DNA into many fragments with sticky ends. Hydrogen bonding to create complementary sequence. DNA ligase catalyzes formation of covalent bonds to connect DNA complementary strand to the plasmid |
|
|
Term
| How can researchers be sure that the vector contains the segment of DNA and that the vector was incorporated into the bacterial cell? |
|
Definition
| By introducing the cell to an environment in which it would not survive in without the gene of interest. (EG. ampicillin resistance, put cells into ampicillin and see which ones survive) |
|
|
Term
| What is a DNA library? How is a DNA library made? what is the difference between a genomic DNA library and a cDNA library? |
|
Definition
Collection of many recombinant vectors each with a fragment of chromosomal DNA.
Treatment of chromosomal DNA with restriction enzymes yields tens of thousands of different fragments
2 types of common DNA libraries
-Genomic – inserts derived from chromosomal DNA
-cDNA – use reverse transcriptase to make DNA from mRNA of interest (complementary DNA) - lacks introns so simpler to use |
|
|
Term
| How is DNA amplified without the use of a vector? |
|
Definition
| PCR. Uses high concentration of primers which are complementary to sequences at the end of the segment of DNA needing replication. |
|
|
Term
|
Definition
Determines base sequence of DNA, Sanger Method
Dideoxy chain-termination method or dideoxy sequencing
Dideoxynucleoside triphosphates (ddNTPs) are missing the 3’ –OH group and will terminate the chain
4 tubes with many copies of single stranded DNA of interest
Each tube has a different radiolabelled dNTP
DNA polymerase will make complementary strand until dNTP inserted and chain terminates
After electrophoresis, DNA sequence can be read by reading which base is at the end of the DNA strand
Procedure has been automated using fluorescent dyes in one tube
used for short sequences, shot-gun sequencing to follow |
|
|
Term
| What are microarrays and why are they useful? |
|
Definition
Can Identify Which Genes Are Transcribed by a Cell.
Used to monitor the expression of thousands of genes simultaneously
Short sequences of known genes attached to spots on slide
Goal to find out which genes are transcribed into mRNA in particular sample of cells
mRNA isolated from those cells and used to make fluorescently labeled cDNA
cDNAs that are complementary to the DNAs in the microarray will hybridize
If the fluorescence intensity in a spot is high, a large amount of cDNA was in the sample that hybridized to the DNA at this location |
|
|
Term
| What is DNA fingerprinting? |
|
Definition
| In electrophoresis, each band is a group of DNA fragments with the same mass |
|
|
Term
| How can we clone a mammal? |
|
Definition
| remove nucleus from egg cell in host. Insert mammary cell into egg. Nucleus in cell in egg initiates embryo development. Zygotes are put into host mammal and pregnancy proceeds. |
|
|
Term
| how does gene therapy work? What are the other uses of dna technology? |
|
Definition
| ...(pharming, bioremediation, etc.) |
|
|
Term
| What is the difference between the intrinsic and extrinsic pathway? |
|
Definition
| The intrinsic pathway goes through the mitochondria (due to UV radiation, chemo, misfolding proteins, and hypoxia. Extrinsic pathway is on the exterior of the cell, receptors on the cell surface activate caspases that carry out death response. |
|
|
Term
| How does DNA polymerase 3 work? |
|
Definition
|
|
Term
| What does topoisamerase do? |
|
Definition
| Relieves torque. Travels ahead of helicase. |
|
|
Term
| DNA polymerase works in which direction? |
|
Definition
|
|
Term
| What types of spindle microtubules are involved in mitosis? What does each type do? |
|
Definition
Astral: positions spindle in cell (~astrology-star positions)
Polar: One on each pole of the cell
Kinetochore: attaches to the chromosome to pull towards poles |
|
|
Term
| When and how does crossing over occur (in genetics)? |
|
Definition
| During Meiosis Prophase 1 when the tetrad forms. |
|
|
Term
| The spindle is attached to what? What compound is at the point where it attaches? |
|
Definition
| Attached to the centromere by kinetochore proteins |
|
|
Term
|
Definition
| Chromosomes come in pairs. (each type is a set of two- "di") |
|
|
Term
|
Definition
| Chromosomes come singularly. |
|
|
Term
| Describe the chromosomes of eggs and sperm, why are they like this? |
|
Definition
| Haploid because they are gametes (sex cells). To create a human each sex cell can only have half the DNA of a full person. For a diploid (2 of each chromosome) organism this means the gametes are haploid (1 chromosome) |
|
|
Term
| What holds chromosome pairs together? What is the "center point" of chromosomes called? |
|
Definition
| A protein called Cohesin (sounds like cohesion!). The center is the centromere. |
|
|
Term
| What is a sister chromatid? |
|
Definition
| Identical parts (containing the same genetic information) which together form a single chromosome |
|
|
Term
| What component is used during mitosis that is found almost solely in animal cells (and not in other Eukaryotes)? What does it do? |
|
Definition
|
|
Term
| What does the Mitotic Spindle do? |
|
Definition
| Organizes and sorts the chromosomes during mitosis. |
|
|
Term
| How does crossing over (in chromosomes) occur? What does it help with? |
|
Definition
The inner two chromatids of the Tetrad may break and rejoin each other in various places. Exchanges material between Homologous chromosomes.
Helps produce a greater variation of possible offspring |
|
|
Term
| What 3 kinds of proteins are needed for transcription? |
|
Definition
1) RNA polymerase II
2) 5 general transcription factors (GTFs)
3) Large Protein Complex (Mediator) |
|
|
Term
| Acetylation vs. Methylation? |
|
Definition
| The first is associated with activation, the second with inhibition |
|
|
Term
| When does post-transcriptional control start? |
|
Definition
| after there is an mRNA transcript splicing of introns and/or speed of transport affects the amount of gene product |
|
|
Term
| Where does mRNA travel from and to? |
|
Definition
| Carries transcripted information from the nucleus to the cytoplasm |
|
|
Term
| What differs between translational and post-translational control? |
|
Definition
| The first determines how much mRNA is translated into protein product. The latter affects the activity of the protein product |
|
|
Term
| What is a Point mutation? |
|
Definition
| Alter a single base pair by base substitution or the addition or subtraction of a base pair |
|
|
Term
| How do Mutagens alter DNA? |
|
Definition
Disrupt pairing by altering the nucleotide structure and by alkylating bases
Interferes with replication by inserting between bases and distorting the Helix |
|
|
Term
| What is the role of the Proto-oncogene? |
|
Definition
|
|
Term
| What is the role of tumor-suppressor genes in cancer? |
|
Definition
| mutation in gene that limits cell growth, promotes DNA repair, trigger apoptosis. In cancer mutation of this can cause cell death to not occur and repair of DNA to be inhibited. |
|
|
Term
|
Definition
| Invasion of cells into area where they are not supposed to be (as is seen in malignant tumors) |
|
|
Term
|
Definition
| Proliferation of a cell type (usually used to describe cancer cells) |
|
|
Term
| What are the classes of tumors? |
|
Definition
Benign: Tumor mass that contains cells able to proliferate
Malignant: Tumor mass that contains cells able to proliferate and invade |
|
|
Term
| What are some common ways to diagnose cancer? |
|
Definition
Biopsy: remove a sample of cells and complete microscopic evaluation (type and degree of cancer)
Gene sequencing: determine therapeutic route (chemo, drug) |
|
|
Term
| What are some common ways to treat cancer? |
|
Definition
| Surgery, radiation and chemotherapy, prescriptions |
|
|
Term
| What is molecular therapy? What does it do? |
|
Definition
Inactivate oncogene product via immunotherapy
Herceptin binds to ErbB2 product to treat breast cancer |
|
|
Term
|
Definition
| Harness body's immune system to fight cancer |
|
|
Term
| What part of DNA can DNA polymerase NOT replicate? why? |
|
Definition
| The tip of the DNA strand with the 3' because there is no upstream promoter |
|
|
Term
| What is correlated to cellular senescence? |
|
Definition
| Progressive shortening of telomeres |
|
|
Term
| What is found in abundance in cancer genomes? |
|
Definition
|
|
Term
| What are the 3 levels of DNA compaction? |
|
Definition
1) DNA wrapping
2) 30-nm Fiber
3) Radial Loop Domains |
|
|
Term
| During DNA wrapping, what does the DNA wrap around and to form what? What is it's purpose? |
|
Definition
| DNA wraps around histones to form nucleosomes. Shortens the length of the DNA 7-fold |
|
|
Term
| During 30-nm step of DNA compaction, what happens and what is the purpose? |
|
Definition
| 3D zigzag of nucleosomes (zipper look) in order to shorten DNA 7 fold |
|
|
Term
| During the radial loop domains step of DNA compaction, what happens and why? |
|
Definition
| Interaction between 30nm and nuclear matrix |
|
|
Term
| What is the central dogma? (regarding genes) |
|
Definition
DNA goes through TRANSCRIPTION to create RNA
RNA goes through TRANSLATION to create proteins |
|
|
Term
| What is the simple explanation for the path by which DNA becomes proteins? |
|
Definition
| Information on the DNA (in the nucleus) is transcribed to mRNA which carries the info outside of the nucleus. The info from the mRNA is translated by tRNA and rRNA into proteins |
|
|
Term
| What are the functions of the 3 forms of RNA polymerase? Which one requires extra transcription factors? |
|
Definition
RNA polymerase II: transcribes mRNA
RNA polymerase I and III: transcribes nonstructural genes for rRNA and tRNA
RNA polymerase II requires 5 extra transcription factors |
|
|
Term
| What enables the transcript to exit the nucleus? What is the function? |
|
Definition
| Poly A tail added to the 3' end and a cap onto the 5' end. Tells ribosome where to attach and promotes longevity in cytosol |
|
|
Term
| What are the function of the 2 subunits of a ribosome? |
|
Definition
small subunit recognizes and binds to mRNA
large subunit synthesizes proteins and binds to tRNA |
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Term
| What does tRNA do? What structural commonalities do all tRNA have? Where does it bind in Protein synthesis? |
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Definition
Binds to free amino acids in cytoplasm and delivers them to ribosome. different tRNAs for each codon.
Cloverleaf structure, Anticodon, Acceptor stem for amino acid binding
binds to large subunit of ribosome |
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Term
| In translation: why does binding occur? |
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Definition
| codon/anticodon recognition |
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Term
| What is in the P site? What is in the A site? |
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Definition
| Peptidyl tRNA, Aminoacyl tRNA |
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Term
| What is nondisjunction and what does it cause? |
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Definition
| Chromosomes do not sort properly during cell division. During meiosis can result in gametes with too many or too few chromosomes |
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Term
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Definition
|
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Term
| How does Polymerase Chain Reaction (PCR) work? |
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Definition
Copy DNA without vectors and host cells
Goal to make many copies of DNA in a defined region
Uses high concentration of two primers that are complementary to sequences at the ends of the DNA region to be amplified, deoxynucleoside triphosphates (dNTPs), and a heat-stable form of DNA polymerase called Taq polymerase
Sample of DNA taken through repeated cycles of denaturation, annealing and synthesis
Thermocycler automates this process
After 30 cycles of amplification, a DNA sample will increase 230-fold |
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Term
| Why use heat-resistant Taq polymerase? |
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Definition
| Process of PCR uses a thermocycler (which heats the sample) to denature, anneal, and synthesize heat resistant DNA |
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Term
| What two types of regulatory elements are there? What is the difference? |
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Definition
| cis-regulatory and trans-regulatory. Cis-regulatory are the binding sites of the transcription factors and the trans-regulatory are the DNA sequences that encode transcription factors |
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Term
| What are the 4 cis-acting regulatory elements? |
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Definition
Promoter
Enhancer
Silencer
Response Element |
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Term
How are nanoparticles being used to treat
cancer? |
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Definition
| Put into the body these particles bind to the outside of cancer cells and act as markers. These markers show up in near-infrared light. |
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Term
| What 4 criteria must genetic material meet? |
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Definition
Information
Replication
Transmission
Variation |
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Term
| What are the 3 components of DNA nucleotides? |
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Definition
1) Phosphate group
2) Pentose Sugar
3) Nitrogenous Base |
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Term
| Which two bases of DNA are the purines? Which two are the pyramidines? |
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Definition
|
|
Term
| What kind of bond connects nucleotides? |
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Definition
|
|
Term
| What does the phosphodiester bond do? |
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Definition
| phosphate group linking two sugars |
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Term
| What 3 things are involved in DNA strand separation? |
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Definition
| Helicase, ssbp, topoisomerase |
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