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108 Cards in this Set
- Front
- Back
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Why do cells divide?
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1. Grow-from one cell to trillions
2. Repair damage-boo-boo's need to heal; how somatic cells are replaced 3. Reproduce-if you're a one celled creature |
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What is bacteria reproduction called?
What do they not do? |
Binary fission or Prokaryote Fission
Do NOT do mitosis |
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Steps for bacteria reproduction. (Long)
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1. Ring of DNA attached to cell membrane
2. Cell reaches adult size, triggers ring of DNA to replicate 3. Phospholipids and peptidoglycans add to cell membrane between 2 DNA attachment points, pushes them apart. 4. cell membrane and cell wall pinch in, form 2 new identical daughter cells 5. Daughter cells grow into adult size...repeats. |
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Define cytokinesis
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cells moving, cell and cytoplasm splitting in 2
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how long does it take for bacteria to reproduce?
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20 minutes
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What positive effect does a fast reproduction cycle have for bacteria?
negative effect? |
mutations to catch hold quickly in a population if beneficial
mutations in bacteria are usually bad |
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Define Mitosis
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nuclear division
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Why is it not mitosis when bacteria reproduce?
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bacteria have no nucleus to divide.
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who made the word mitosis?
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Fleming
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Greek word for "mitos" means?
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Threads
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What does mitosis maintain from one generation to the next?
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the chromosome number in cells
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When is DNA visible in light microscopes?
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When DNA wraps around histone spools
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What does a chromosome consist of?
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One DNA molecule + histone proteins wound up together
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What is the mitosis game plan?
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wants 2 daughter cells, identical to parent cells
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what are the "recipes" needed to create a person called?
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genes
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how many genes on a chromosome?
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More than one
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What are the bases?
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T, A, C, G
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how many genes are needed to make proteins?
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30,000
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What writes recipes for proteins?
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DNA
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Genes make proteins, proteins make...?
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what you look like and how you work
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Beadle and Tatum's definition of a gene.
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"One gene codes for one polypeptide chain"
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Mendelian definition of gene.
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"A unit of heritable information"
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Polypeptide chains have to do with...?
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building proteins
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What is the "waist line" in the chromosome called?
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Centromere
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During most of a cell's life cycle, chromosomes are in the what state?
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unduplicated state-when cell hasn't copied itself yet
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What is the belt that holds the chromosomes together until needed to separate in mitosis called?
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Kinetochore
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What is the kinetochore made of?
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protein
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What does the kinetochore hold together?
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2 identical chromosomes; sister chromatids, EXACTLY IDENTICAL
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What are sister chromatids that are still attached with kinetochore still considered?
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One chromosome in duplicated state
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Define Sister chromatid
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identical to each other-no way of telling which was the original
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How complex an organism is, is somewhat relative to what?
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quantity of DNA *how long it is*
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Chromosome numbers are the same within?
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the same species, species specific
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Humans have 46 chromosomes in what cells? exceptions?
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somatic cells
liver and red blood cells are exceptions |
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What are red blood cells missing?
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nucleus and chromosomes
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Why do red blood cells have no nucleus?
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created in bone marrow, leaves nuclei in marrow.
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How long do red blood cells live?
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120 days
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Define diploid
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2 sets of instructions in each somatic cell (2N)
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What is each pair of instructions called?
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homologous pair of chromosomes
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Centromere separates arms:
What is the shorter arm called? What is the longer arm called? |
short arm=p arm
long arm=q arm |
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define homologues
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2 separate chromosomes
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define locus
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Think of it as address, location
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Define allele
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different form of traits, "flavors"
genes w/ different flavors |
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Define karyotype
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test of chromosomes pictures
photographic testing of chromosomes, matching, cut and past to find abnormalities |
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What is the criteria for matching chromosomes?
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-find length
-bands pattern -position of the centromere |
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What are cells with only one set of instructions called?
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haplid (N)
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what stage is the picture taken for a karyotype test?
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metaphase
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what is the fastest part of mitosis called?
when is it? |
cleavage
first 3 days |
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what is it called when a cell commits suicide?
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apoptosis
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how long (percent) is a cell in interphase?
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95%
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what stains darker inside the nucleus?
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nucleolus
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No mitosis can occur if what are removed?
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centrosomes
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What do plants have in the centrosome?
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nothing
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On what do chromosomes travel during mitosis?
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spindle fibers
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What is the job of the nucleolus?
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directs the making of ribosomes
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What is the constricting at the equator of an animal cell called?
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cleavage furrow
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In animal cells, what is it called when microtubules begin constricting cell, creating a cleavage furrow?
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cytokinesis
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Define Cell Plate Formation
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phospholipid wall between new cells, cellulose becomes deposited in phospholipid and becomes new cell wall.
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Who does Cell Plate Formation? Why?
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-Plant cells/fungi cells
-cell wall won't let cleavage furrow form-too ridgid |
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What is special about your skeletal muscles?
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Have had the same ones since you were born; gotten bigger bu no new ones
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What are skeletal muscles made out of?
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1 long big fiber with a lot of nuclei but no cell membrane
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We can find the cure for cancer if we can figure out what?
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the regulation of mitosis
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What state are most cells in the body in?
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G0
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What does a cell do while in G0?
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not doing mitosis, doing other jobs
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What cells do the most mitosis?
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hair and skin cells
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In the experiment where 2 cells, in different stages, were fused. What did this prove?
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Chemical signals regulate mitosis, chemically driven process
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What are the 2 main types of regulationg proteins?
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CDK's and Cyclins
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Define Kinases
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category of enzymes, puts phosphate gropus on and off things
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Define phosphoralate
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stick phosphorate on something
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What protein remains constant throught the cell cycle?
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CDK
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Unless attached to Cyclin, what is CDK considered?
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inactive
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Define Cyclin
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protein whose concentration fluctuates throughout cell cycle.
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Cyclin + CDK = ?
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MPF's
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What do MPF's do?
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a few MPF's get phosphoralted which triggers more phosphorylation of MPF's and the cell passes the G2 check poing and mitosis begins
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What do activated MPF's do? (2 things)
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1. cause cyclin production to cut down
2. increase proteases that "eat" the cyclin part of the MPF |
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Mitosis is complete when what levels are down?
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MPF levels
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What is cancer?
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unregulated mitosis
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What is G1 probably restricted by?
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mostly P53's
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What does P53 do?
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tells cell to repair itself, if it cant be fixed, apotosis
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How can cells in G0 be triggered into S?
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by an injury
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Define Density-Dependent Inhibition
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-cells next to injury site begin to divide, fill in and then stop dividing
-when cells are touching on one single layer, mitosis stops |
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Define Anchorage dependence
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Cells must be "ON" some surface to grow.
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Define Metastisizing
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spreading of cells, no following anchorage dependence
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How does your body know when you're injured?
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red blood cells destroyed by injury=pieces of blood cells (platelets)=release PDGF which is a growth factor
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Define Growth Factor
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proteins that stimulate mitosis
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What do these stand for and what do they stimulate?
1. EGF 2. PDGF 3. IGF 4. NGF |
1. Epidermal growth factor, stimulates skin
2. platelet derived growth factor, stimulates cyclin 3. insulin-like growth factor, stimulates fat 4. nerve growth factor, stimulates nerves |
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Define protooncogene
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genes that are activated by growth factors
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Define oncogene
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mutated protooncogenes that over express resultes
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How many prootoncogenes known?
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Over 30
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well known protooncogenes?
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ras, mol, myc, fos, jun
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Define tumor-suppressor genes
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genes that produces proteins that block oncogenes, keep protooncogenes in check
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what is the #1 suppressor gene?
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P53
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what % of breast cancer are related to BRCA1 or BRCA2?
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15%
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What does Rb do?
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prevents Retino blastoma
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what are 2 shapes that amino acids take?
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beta-pleated sheets
alpha helixes |
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important stuff on P53 (5 things)
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-doesnt do anything in normal healthy cells
-will stop cell in G1 until DNA can be repaired -triggers apoptosis -can override most all other mutations -works even if only one copy is correct |
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how many codons does a P53 gene have?
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393
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what does BRCA1 and BRCA2 cause?
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most forms of heritable breast cancers
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Define Redundancy
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takes more than one mutation to screw up. System for safeguarding
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What are the 5 steps to redundancy?
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1. mutation in one of the two APC genes
2. mutation in second APC gene 3. Becomes an oncogene 4. loss of the tumor-suppressor gene 5. mutation of P53 |
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Define telomeres
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at end of each chromosome-long tandem repeats
TTAGGG in humans |
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Define Hayflick Limit
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about 50ish rounds of mitosis, the cells just stop doing mitosis, hits old age, not a death sentence
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Every time a cell goes through mitosis what happens?
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lagging strand gets a little shorter, telomeres get cut off
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define senescense
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old age
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What are some examples of cells hitting the hayflick limit?
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dermal fibroblasts-lose elasticity, wrinkle, become thin
-lining of blood vessels-link sugars and be come atherosclerotic |
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Define telomerase.
what's it made of? What does it act like? |
-enzyme that puts TTAGGG back on the end
-mix of RNA and protein -reverse transcriptase |
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what cells is telomerase found?
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reproductive and skin cells
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What did Cech discover?
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all enzymes are not proteins, a couple RNA's can autoenzyme themselves and each other
-called these ribosomes |
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What is found in high levels of virtually all cancer cells?
what does this do? |
Telomerase, makes cells immortal
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