Term
| What is the enzyme that is responsible for copying the ends of chromosomes? |
|
Definition
|
|
Term
| What is the total set of all the genetic material of an organism called? |
|
Definition
|
|
Term
| What is the name for the parts of the electromagnetic spectrum that can induce damage to DNA? |
|
Definition
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|
Term
| In what stage does microtubules align the sister chromatids on the metaphase plate? |
|
Definition
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|
Term
| What portion of the cell cycle is responsible for dividing the duplicated DNA into two identical cells? |
|
Definition
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|
Term
| What makes up the microtubule organizing centers called centrosomes? |
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Definition
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|
Term
| What is the genotype of a human male? |
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Definition
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|
Term
| What is the name for the identically copied chromosomes joined by a centromere? |
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Definition
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|
Term
| In what stage does the kinetochore microtublues attach to the sister chromatids? |
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Definition
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|
Term
| What is the proto-oncogene that turns on cyclins and other genes to prepare for cell division? |
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Definition
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|
Term
| What does DNA + Histones make? |
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Definition
|
|
Term
| What are the monomers that make up microtubules? |
|
Definition
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|
Term
| Protein that turns a gene off is known as a transcription ____________. |
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Definition
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|
Term
| What are proteins that package DNA in eukaryotes called? |
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Definition
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Term
| Refers to cancer's ability to spread to other tissues. |
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Definition
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|
Term
| Refers to cancer's ability to by-pass the cell cycle and continue to grow. |
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Definition
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|
Term
| Genes that tell a cell to continue to divide. |
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Definition
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|
Term
| Chemical factors (besides Cdks) that are sometimes necessary for the progression of the cell cycle. |
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Definition
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|
Term
| What are chemicals that induce mutation, such as those found in cigarettes, called? |
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Definition
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|
Term
| What is the area along the Metaphase plate, where a new cell wall is formed during cytokinesis in plant cells, called? |
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Definition
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|
Term
| What stage do the sister chromatids separate and move3 to opposite poles? |
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Definition
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|
Term
| What is the tumor supressor gene that prevents the cell from dividing before its DNA can be repaired (part of the G2 checkpoint)? |
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Definition
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|
Term
| All cells that make up an organism besides its sex cells. |
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Definition
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Term
| Refers to the central principle of molecular biology where DNA is made into proteins. |
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Definition
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|
Term
| What is the mitotic structure responsible for physically driving mitosis? |
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Definition
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|
Term
| Humans have 23 pairs of these. |
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Definition
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|
Term
| What type of mutation involves only one nucleotide of DNA? |
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Definition
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|
Term
| What does does the nucleus reform and cleavage furrow begins to form? |
|
Definition
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|
Term
| What area along the Metaphase plate constricts during cytokinesis in animal cells? |
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Definition
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|
Term
| What stage does chromatin condense? |
|
Definition
|
|
Term
| What is the term for sex cells? |
|
Definition
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|
Term
| What is the term for cellular suicide? |
|
Definition
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|
Term
| What type of supressor gene tells cells not to divide? |
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Definition
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Term
| Protein that turns a particular gene on. |
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Definition
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|
Term
| What process results in the division of two daughter cells at the end of mitosis? |
|
Definition
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|
Term
| What is the process of cell division in prokaryotes? |
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Definition
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|
Term
| A disease caused by the failure of the normal cell cycle due to mutation. |
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Definition
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|
Term
| What checkpoint makes sure DNA has been properly replicated before allowing the cell cycle to continue? |
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Definition
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|
Term
| What motor proteins are responsible for cytokinesis? |
|
Definition
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|
Term
| What physical factor can influence the cell cycle? |
|
Definition
|
|
Term
| What process results in nuclear division? |
|
Definition
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|
Term
| One of the roles of the cell cycle. |
|
Definition
|
|
Term
| What portion of the cell is responsible for growth and DNA duplication? |
|
Definition
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|
Term
Acessory proteins to special kinases involved in the cell cycle that activate the kinase.
Levels fluxuate during the cell cycle. |
|
Definition
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|
Term
| Refers to cancer's ability to recruit new blood vessels. |
|
Definition
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|
Term
| What monomers make up microfilaments? |
|
Definition
|
|
Term
| In what phase of the cell cycle is DNA duplicated? |
|
Definition
|
|
Term
| Cyclin (cyclin B) + kinase (cdc2) that are directly responsible for progression of the mitosis phase of the cell cycle. |
|
Definition
|
|
Term
| What are the three roles of the cell cycle? |
|
Definition
Reproduction
Growth
Tissue repair |
|
|
Term
|
Definition
| The total set of genetic instructions that make-up an organism |
|
|
Term
| What generally has a larger genome prokaryotes or eukaryotes? |
|
Definition
|
|
Term
| How is a large genome possible? |
|
Definition
| Managed through the use of organizational sub-units of DNA called chromosomes |
|
|
Term
| Distinguish between eukaryote and prokaryote chromosomes. |
|
Definition
Eukaryotes: Linear chromosomes with histones
Prokaryotes: single, circular chromosome with associated proteins |
|
|
Term
| Which type of cells has histones? |
|
Definition
|
|
Term
| Which type of cells are linear? |
|
Definition
|
|
Term
| Which type of cells are circular? |
|
Definition
|
|
Term
| Which type of cells have origin of replication? |
|
Definition
|
|
Term
|
Definition
| DNA + Histones; which make up chromosomes |
|
|
Term
| What are the functions of histones? |
|
Definition
Packaging proteins
DNA is tightly wound around histones |
|
|
Term
| How many chromosomes are in humans? |
|
Definition
|
|
Term
| How many pairs of chromosomes are in humans? |
|
Definition
|
|
Term
| Where do these chromosomes come from? |
|
Definition
|
|
Term
| Know each stage of the cell cycle and what occurs in each. |
|
Definition
Interphase:
G0 - A resting phase where the cell has left the cycle and has stopped dividing.
G1 - 1st gap; growth
*G1 checkpoint - Nutrients available
S - DNA synthesis; 4n=92
G2 - 2nd gap; growth
*G2 checkpoint - Make sure DNA is correct
**Apoptosis - Cell suicide
M - Mitosis/cytokinesis; 2n
*Mitosis - Nuclear division
**Cytokinesis - cytoplasm split to form two new cells |
|
|
Term
| What type of cells undergo mitosis? |
|
Definition
|
|
Term
| What type of cells undergo meiosis? |
|
Definition
|
|
Term
| What are the 5 stages of mitosis? |
|
Definition
Prophase
Prometaphase
Metaphase
Anaphase
Telophase |
|
|
Term
| What happens in prophase? |
|
Definition
-Nucleoli gone (site of rRNA synthesis)
-Chromatin condenses
-Early mitotic spindles form
-Centrosomes move apart |
|
|
Term
| What happens in prometaphase? |
|
Definition
-Nuclear envelope breaks apart
-Spindle fibers (microtubules) extend from each spindle pole (centrosome)
-Fibers attach to each sister chromatid at the kinetochore |
|
|
Term
| What happens in metaphase? |
|
Definition
-Microtubules push and pull sister chromatids
-Sister chromatids align on metaphase plate |
|
|
Term
| What happens in anaphase? |
|
Definition
-Sister chromatids split apart at the centromeres
-Chromatids move into a V shape as they are pulled to each pole by shortening the microtubule spindles at the kinetochore
-Centrosome poles in the cell move farther apart from each other |
|
|
Term
| What happens in telophase? |
|
Definition
-Daughter nuclear envelope and nucleolus begin to reform
-Cleavage furrow forms
-Chromatin uncoils and chromosomes are less distinct
-End of mitosis, beginning of cytokinesis |
|
|
Term
|
Definition
| DNA + histones; which make up chromosomes |
|
|
Term
| What is a sister chromatid? |
|
Definition
| Each copied chromosome consists of two identical sister chromotids |
|
|
Term
|
Definition
| Area where mitotic spindles originate |
|
|
Term
|
Definition
| Centrioles are cylindrical structures that are composed of groupings of microtubules; which help to organize the assembly of microtubules during cell division. |
|
|
Term
|
Definition
This entire structure is collectively known as the spindle:
-microtubules attached to sister chromatids at the kinetochores on each side
-sister chromatids are attached to each other at the centromere |
|
|
Term
| What is a metaphase plate? |
|
Definition
| Invisible plane that sister chromatids align on during metaphase |
|
|
Term
|
Definition
| Attachment site for microtubules to sister chromatids |
|
|
Term
|
Definition
Microtubules are fibrous, hollow rods, that function primarily to help support and shape the cell. They also function as routes along which organelles can move.
They form the spindle fibers that manipulate and separate chromosomes during mitosis. |
|
|
Term
|
Definition
| Chromatids are attached to each other in these regions |
|
|
Term
| What is a cleavage furrow? |
|
Definition
Forms near metaphase plate
Contractile ring made of actin and the motor protein myosin. Ring contracts pinching the cell in two. |
|
|
Term
| What is actin and which cytoskeletal component does it make up? |
|
Definition
| Actin is a protein that forms the cytoskeletal component microfilaments |
|
|
Term
| What is tubulin and which cytoskeletal component does it make up? |
|
Definition
| Tubulin is a protein that forms the cytoskeletal component microtubules |
|
|
Term
| What is the function of a kinetochore? |
|
Definition
Attachment site for microtubules to sister chromatids.
Mediate proper chromosome segregation during cell division |
|
|
Term
| How does a kinetochore work? |
|
Definition
| Kinetochore microtubules shorten during anaphase by depolymerization into tubulin sub-units; which results in chromosome moving forward towards the centrosome |
|
|
Term
| What end of the microtubule shortens? |
|
Definition
| The end attached to the chromosome |
|
|
Term
| What causes the sister chromatid to "walk"? |
|
Definition
|
|
Term
| What evidence is there to support this function (sister chromatid "walking")? |
|
Definition
| Experiments with marking microtubules show shortening only on the ends near the kinetochores |
|
|
Term
| What is the function of the non-kinetochore microtubules? |
|
Definition
| Non-kinetochore microtubules are responsible for lengthening the cell along the axis defined by the poles |
|
|
Term
| How does cytokinesis work? |
|
Definition
| The cytoplasm of a cell is divided into two daughter cells |
|
|
Term
| What motor and cytoskeletal proteins are involved in cytokinesis? |
|
Definition
| Microfilaments (actin) and myosin |
|
|
Term
| What is the difference between plants and animal cytokinesis (know the terms)? |
|
Definition
Animals: cleavage furrow
Plants: cell plate |
|
|
Term
| How do plants perform cytokinesis? |
|
Definition
Vesicles from the golgi containing cell wall material come together on the metaphase plate to form a cell plate (new cell wall) between the two daughter cells.
Cell plate grows in size and eventually fuses with the plasma membrance; dividing the cells in two. |
|
|
Term
| Where do the materials come from for plants to perform cytokinesis? |
|
Definition
|
|
Term
| How do prokaryotes reproduce? |
|
Definition
|
|
Term
| How is binary fission different from mitosis? |
|
Definition
Since bacteria have single, circular chromosome with associated proteins(not linear with histones like eukaryotes):
-replication begins at a single point known as the origin of replication
-as the DNA replicates, it begins to move to opposite ends of the cell
-plasma membrane grows inward pinching them in two |
|
|
Term
| What organisms have modified mitosis? |
|
Definition
|
|
Term
| What part of mitosis is different for each one? |
|
Definition
Dinoflagellates: replicated chromosomes are attached to the nuclear envelope
Diatoms: spindle develops within the nucleus |
|
|
Term
| Why are checkpoints so important for the cell cycle? |
|
Definition
| To prevent uncontrolled cell growth and mutations |
|
|
Term
| What happens if these checkpoints are turned off? |
|
Definition
Cells continue dividing even if they are mutated.
Normal cells undergo apoptosis after 20-50 divisions. Cancer kills by introducing randomness to an ordered system. |
|
|
Term
| What do "normal cells" do when they don't meet the criteria for each checkpoint? |
|
Definition
| Stop cell division until criteria is met or undergo apoptosis (pre-programmed cell death) |
|
|
Term
What is the name of the three checkpoints?
When during the cell cycle do they occur?
Explain what each checkpoint is for? |
|
Definition
G1 Checkpoint occurs at the end of G1 phase, makes sure the environment is good (enough nutrients available to replicate) and cell size is adequate.
G2 Checkpoint occurs at the end of G2 phase, makes sure the DNA is correct and the cell is ready for mitosis.
M Checkpoint occurs at the point in metaphase where all the chromosomes have/should aligned on the metaphase plate, makes sure the chromosomes are properly attached to the spindle before anaphase and that daughter cells do not end up with missing or extra chromosomes. |
|
|
Term
| What is G0 and what is it for? |
|
Definition
G0 is resting.
If no signal is received to go to S, then the cell goes into a resting phase where the cell has left the cycle and has stopped dividing. |
|
|
Term
| Know that specific kinases are responsible for cell cycle progression (be prepared to describe what a kinase does). |
|
Definition
Protein kinases that activate or deactivate other proteins by phosphorylating them.
Cyclin Dependent kinases (CDks): depends on an accessory protein called cyclin in order to function properly (levels remain constant)
Cyclins: accessory proteins that binds to CDk and makes it function (levels fluxuate - driving it forward or stopping it) |
|
|
Term
| What accessory proteins are required for these kinases to become active? |
|
Definition
|
|
Term
One of the most important cyclin dependent kinases (Cdks) for this unit (mitosis) is called mitosis promoting factor (MPF) composed of the kinase called cdc2 and the Cyclin called type B. Cyclin B increases just before mitosis and is destroyed just after.
What would happen if cyclin B wasn’t destroyed after M phase? |
|
Definition
| Mitosis would continue and would not transition out of M to G1 |
|
|
Term
| What if cyclin B was never made to begin with? |
|
Definition
| Mitosis would not begin since cyclin B triggers the cell's passage past the G2 checkpoint into M phase. |
|
|
Term
| What are some other chemical factors (besides cyclins and their kinases (CDks)) that are important to some cell types in order to progress through the cell cycle? |
|
Definition
Growth factors - platelet derived growth factor (PDGF) produced by platelet blood cells stimulates cell division
-fibroblasts cells will not divide without PDGF present |
|
|
Term
| What would happen if cells did not have this additional "factor"? |
|
Definition
| Cells would fail to divide |
|
|
Term
| What are the physical factors that can influence the cell cycle? |
|
Definition
Anchorage Dependence
Density Dependent Inhibition |
|
|
Term
| Distinguish between the two physical factors that influence the cell cycle. |
|
Definition
Anchorage Dependence:
floating cells stop dividing
Density Dependent Inhibition:
crowded cells stop dividing |
|
|
Term
|
Definition
Cancer cells are the products of normal cells that have been mutated (usually in cell cycle genes)
Cancer cells do not respond to the body's normal cell cycle control systems. Somehow these "faulty cells" by-pass the normal cell cycle system and continue to grow uncontrolled |
|
|
Term
| What are the four factors that characterize cancer? |
|
Definition
1. Uncontrolled cellular growth
2. Ability to spread to other tissues
3. Ability to recruit new blood vessels
4. Immortality |
|
|
Term
| Know the terms for the factors that characterize cancer and why these are important to the development of cancer. |
|
Definition
1. Tumorgenesis (uncontrolled growth)
2. Metastasis (ability to spread)
3. Angiogenesis (recruit blood vessels)
4. Immortality |
|
|
Term
Cancer cells need to feed.
How do cancer cells do this? |
|
Definition
| Recruit new blood vessels |
|
|
Term
| What is a transcription factor? |
|
Definition
| Special proteins that control which genes are turned on (transcribed into mRNA) in that particular cell at that particular time |
|
|
Term
| What is a transcription suppressor? |
|
Definition
| Special proteins that control which genes are turned off (not transcribed into mRNA) in that particular cell at that particular time |
|
|
Term
| Why are transcription factors and suppressors important? |
|
Definition
| To control the flow (or transcription) of genetic information from DNA to mRNA |
|
|
Term
| What is a tumor suppressor gene and what does it do? |
|
Definition
p53 is activated by damaged DNA and prevents the cell from dividing until repairs can be made. Blocks unscheduled cell divison. Stop dividing!
*Almost all cancers have a mutation in their p53 gene |
|
|
Term
| What is a proto-oncogene and what does it do? |
|
Definition
Myc is the transcription factor responsible for turning on genes that prepare for cell division; continue dividing!
A normal gene that has the potential to become an oncogene (after mutation) |
|
|
Term
What are the three most prominent things that cause mutation?
Give examples. |
|
Definition
1. Radiation:
-Sun (UV rays)
-X rays
-Natural Decary (Carbon 14)
2. Chemical carcinogens:
-Smoking
-Dioxin (Agent Orange)
3. Mistakes made by the cell during replication |
|
|
Term
| Distinguish between a point mutation, a structural modification, and an irregular copy number. |
|
Definition
Point Mutation: A mutation affecting only one or very few nucleotides in a gene sequence.
Structural Modification: Change to the structure of the chromosome (piece cut off).
Irregular Number: Having extra or missing chromosomes. |
|
|
Term
| What process in the cell cycle is most likely to produce an irregular copy number in daughter cells? |
|
Definition
| Anaphase (separation of sister chromatids) |
|
|
Term
What type of gene is p53?
What is its job?
Why would a mutation in this gene likely lead to cancer? |
|
Definition
Tumor suppressor gene
Prevent cell from dividing until repairs can be made |
|
|
Term
What type of gene is myc?
What is its job?
Why would a mutation in this gene likely lead to cancer? |
|
Definition
Proto-oncogene
Turn on genes that prepare for cell division |
|
|
Term
| Why would mutations in adhesion molecules contribute to cancer? |
|
Definition
| If there is a mutation in adhesion molecules, which are used for cellular area code, the cell could travel to different parts of the body. |
|
|
Term
| What part of cancer development would these adhesion genes contribute to? |
|
Definition
| Metastasis (ability to spread) |
|
|
Term
|
Definition
| An enzyme which adds DNA sequence repeats to the end of DNA strands in the telomere regions, which are found at the ends of eukaryotic chromosomes. |
|
|
Term
| How does telomerase contribute to apoptosis? |
|
Definition
Telomerase activity is promptly detected in cells with an indefinite replicative potential, such as cancer cells, while is almost undetectable in normal cells.
Disruption of the telomere capping function and (or) telomerase inhibition elicit an apoptotic response in cancer cells, while restoration of telomerase activity in somatic cells confers resistance to apoptosis. |
|
|
Term
How is cancer currently treated?
What are the benefits and risks? |
|
Definition
Chemotherapy
Benefits: prevents cells from dividing
Risks:
-kills all cells that are dividing (cancerous or not)
-cancer cells develope drug resistance |
|
|
Term
| What are two new ways of fighting cancer? |
|
Definition
Angiogenesis - new drugs that block cancer's ability to feed itself
Gene Profiling (Microarray analysis) |
|
|
Term
| How does a microarray work? |
|
Definition
Synthesize short DNA sequences of all human genes - imprinted on glass chips; Microarray (DNA) chips
To determine which genes are turned on and which are turned off in a given cell, a researcher must first collect the messenger RNA molecules present in that cell. The researcher then labels each mRNA molecule by using a reverse transcriptase enzyme (RT) that generates a complementary cDNA to the mRNA. During that process fluorescent nucleotides are attached to the cDNA. The tumor and the normal samples are labeled with different fluorescent dyes.
If a particular gene is very active, it produces many molecules of messenger RNA, thus, more labeled cDNAs, which hybridize to the DNA on the microarray slide and generate a very bright fluorescent area. Genes that are somewhat less active produce fewer mRNAs, thus, less labeled cDNAs, which results in dimmer fluorescent spots. If there is no fluorescence, none of the messenger molecules have hybridized to the DNA, indicating that the gene is inactive. |
|
|
Term
| How can microarray "profiles" help battle cancer? |
|
Definition
| Develop new, extremely specific drugs which target each cancer profile |
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