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why cells divide

1. reproduction
2. repair/replacement
3. growth

growth factor

A growth factor is a naturally occurring substance capable of stimulating cellular growth, proliferation and cellular differentiation. Usually it is a protein or a steroid hormone. Growth factors typically act as signaling molecules between cells.

two things a cell needs in order to survive

1. space - contact inhibition
2. good grip - anchorage dependence

cells that break survival rules

cancer cells (overgrowth of cells, breaks rule #1, how cancer spreads, breaks rule #2)

telomere

protective cap at the end of each chromosome, cell dies when it starts to eat away at genes

telomerase

enzyme that rebuilds telomeres, makes cell immortal

cells that telomeres is "on" in

stem cells
gamete cell lines

malignant tumors

grow into organs and disrupt functions

benign tumors

just a tumor, no impact on the body

radiation

cause mutation in DNA, break DNA cancer cell dies

side effect of radiation

cancer

chemotherapy

depending on drug, different cells and mechanisms are targeted

cells targeted by chemo

white blood cells
hair cells
lining of gut
red blood cells

side effects of chemo

hair loss, nausea, suppressed immune system, fatigue

plants crucial to treatment of cancer

rosy periwinkle
vincristine
rinblastine

mitosis

makes new cells that are identical in genetic makeup to the original cell

meiosis

make new cells that have half the chromosomes of the original cell, contain half of genetic information

diploid

two copies of each chromosome

haploid

one copy of each chromosome

genetic variation

1. crossing over
2. independent assortment of chromosomes
3. random fertilization
4. mutation

genome

a cells complement DNA
prokaryotes
eukaryotes

chromosome

discrete molecule of DNA

gene

a portion of a chromosome that codes for a specific trait

locus (plural loci)

the location of a gene on a chromosome

chromatin

the complex of DNA and proteins that makes up a eukaryotic chromosome

sister chromatids

identical copies on a chromosome, joined together by the centromere and eventually separating during mitosis or meiosis 2, until they divide they are considered a single chromosome

chromatids

a single member of a pair of sister chromatids, only called chromatids when joined, called chromosome when they take place in mitosis or meiosis 2

centromere

the narrow "waist" where sister chromatids are joined together

centrioles

"organizing center" in the cell, aids in mitosis

homologous pair

chromosome pairs of the same length, centromere position and staining pattern that possess genes for the same characters/traits at corresponding loci, one pair paternal, or maternal

gametes

egg and sperm, sex cells

somatic

body cells, any cell except gametes

gene deletion

losing a piece of chromosome

gene relocation

portion of gene relocated to a different chromosome, non-homologus

why inheritance is important

1. allows life to give rise to similar life
2. allows good traits to be passed on (evolution, adaptation)

inheritance

ability to pass on characteristics/traits/genes

alleles

alternate version of a gene

mendels law of segregation

only one of two alleles for a gene is put into a gamete

dominant allele

will be expresses in a heterozygous individual

recessive allele

will only be expressed in a homozygous recessive individual

phenotype

how an organism looks; how the gene is expressed

genotype

the alleles that an organism has

mendels law of independent assortment

dominant and recessive don't always sort together, equal probability

incomplete dominance

occurs when a heterozygote exhibits an intermediate phenotype between two homozygotes

sickle - cell disease

homozygous disease, incomplete dominance

why is sickle - cell still here?

1. malaria - parasite
2. heterozygous, get resistance to malaria

blood type

case of co-dominance, alleles are both fully expressed in heterozygote

polygenic traits

lots of different genes contributing to one trait

pleiotrophy

one gene effecting many traits
1. disrupts red blood cells
2. causes cells to be inhospitable to material parasites

linkage

the closer the genes are on a chromosome the more likely they will be inherited together

epistasis

one gene controlling the expression of another

huntingtons disease

fatal dominant autosomal disease, onset 30s and 40s, late onset (after reproduction)

most disorders are autosomal recessive diseases

DD - not affected
dd - affected
Dd carriers (not affected, but can pass it on)

autosomal recessive diseases

likely polygentic
1. schizophrenia and bipolar disease
2. autism

color blindness, hemophilia

sex linked recessive disorder carried on X chromosome

to be colorblind

female must inherit from both parents
male must inherit from your old hen

to have normal vision

female can inherit normal vision from mom or dad
male must inherit normal vision from mom

aneuploidy

Aneuploidy is an abnormal number of chromosomes, and is a type of chromosome abnormality. An extra or missing chromosome is a common cause of genetic disorders (birth defects).

x chromosome

turner syndrome
short
learning disabilities
webbed skin between neck and shoulders
underdeveloped ovaries

trisomy

A trisomy is a type of polysomy in which there are three copies, instead of the normal two, of a particular chromosome. A trisomy is a type of aneuploidy (an abnormal number of chromosomes).

xyx chromosome

klinefelter syndrome
overweight
tall
intellectually normal
infertile
development of some female features

xyy chromosome

"super males"
taller than average
moderate to severe acne
lower intelligence

xxx chromosome

"meta females"
sterile
no obvious physical or mental problems

polyploidy

having additional sets of chromosomes

promoter

sequence of DNA that signals the beginning of transcription

players in transcription

promoter
RNA polymerase

terminator

sequence of DNA that signals the end of transcription

RNA polymerase

enzyme that builds the RNA polymer (unwinds DNA reading one side of DNA strand)

splicing

taking/cutting out (introns spliced out)

intron

intervening region

exon

expressed region (exits nucleus)

ribosomes

site of protein synthesis
2 pieces
nucleolus makes subunits

amino acids

20 of them
if you read nucleotides 1 at a time you can code for four amino acids

codon

words of three

transfer RNA (tRNA)

two attached sites
has anti codon, complementary to AUG

ribosome

site of translation

tRNA

translator, amino acid, attachment site, anti-codon (complementary to mRNA codon)

steps in translation

initiation
elongation
termination

initiation

ribosomal subunits, first tRNA join with mRNA

elongation

ribosome moves down mRNA and tRNA's add new amino acids according to the order of codons

termination

when ribosome reaches a stop codon, the ribosome releases the mRNA and the proteins, translation ends.

players in translation

stop codon
start codon

stop codon

ends translation, sequence of mRNA

start codon

begins translation, sequence of mRNA

point mutations

base pair substitution, one nucleotide change can have no effect or great effect

three substitutions of point mutation

silent mutation
missense mutation
nonsense mutation

silent mutation

amino acids sequence remains same

missense mutation

amino acid sequence is changed

nonsense mutation

mutation that changes an amino acid to a stop, polypeptide production stops

frame shift mutation

changes the reading frame, everything after will be different

base pair insertion

insert one or more

base pair deletion

take out one or more

single base pair substitution

cause disease, evolution

translation

process by which info from mRNA is use to synthesize a polypeptide change

transformation

change in a genotype and phenotype to the assimilation of external DNA

central dogma

Taking DNA and making it into a protein

DNA
-transcription
RNA
-translation
protein

Genetic engineering

The process of altering an organism′s DNA. This is usually by design.

Restriction Enzymes

DNA-cutting proteins found primarily in bacteria. Enzymes cleave (cut) the phosphodiester backbone of double-stranded DNA at specific nucleotide sequences (restriction sites). Commercially available restriction enzymes are essential for molecular biology experiments.

Plasmid DNA

Small, circular, self-replicating double-stranded DNA molecules found primarily in bacterial cells. Plasmids often contain genes coding for antibiotic resistance proteins and are routinely used for DNA-cloning experiments.

Substrates

Molecule or molecules on which an enzyme performs a reaction.

Palindromes

A word or phrase that reads the same forward and backward (for example, "a toyota"). In the context of biotechnology, a DNA sequence with complementary strands that reads the same forward and backward. Most restriction enzyme recognition sequences are palindromes.

Recognition sequence

Specific sequence of DNA nucleotides recognized and cut by a restriction enzyme.

Restriction Site

Specific sequence of DNA nucleotides recognized and cut by a restriction enzyme.

Cohesive ends

Overhanging single-stranded ends of a DNA molecule created by the action of certain restriction enzymes.

Blunt ends

Double-stranded ends of a DNA molecule created by the action of certain restriction enzymes.

Vectors

DNA (or viruses) that can be used to carry and replicate other pieces of DNA in molecular biology experiments; for example, plasmid DNA, viruses used for gene therapy; also refers to organisms that carry disease.

Transformation

The process by which bacteria take in DNA from the surroundings. Term also is used to define changes that cause a normal cell to become a cancer cell.

Electroporation

A process for transforming bacteria with DNA that uses electrical shock to move DNA into cells; can also be used to introduce DNA into animal and plant cells.

Antibiotic selection

Laboratory technique used to identify bacteria containing recombinant DNA of interest; involves growing bacteria on media with antibiotic or other selection molecules.

Origin of replication

Specific locations in a DNA molecule where DNA replication begins.

RNA polymerase promoter

Copies RNA from a DNA template; different forms of RNA polymerase synthesize different types of RNA.

Copy number

The number of copies of a particular DNA molecule or gene sequence such as a plasmid in a bacterial cell.

Insulin

Protein hormone produced by cells of the pancreas; involved in glucose metabolism by cells; deficiencies in insulin production or insulin-receptor production can cause different forms of diabetes.

Humulin

The recombinant form of human insulin, became the first recombinant DNA product to be approved for human applications by the U.S. Food and Drug Administration.

Lytic cycle

A process of bacteriophage replication that involves phages infecting bacterial cells and then replicating and rupturing (lysing) the bacterial host cells.

Plaques

Small clear spots of dead bacteria appearing on a culture plate, caused by bacterial cell lysis by bacteriophage.

Expression vectors

DNA vector such as a plasmid that can be used to produce (express) proteins in a cell.

Cosmid vectors

Large circular double-stranded DNA vector that is used for gene-cloning experiment in bacteriophages.

BAC

Large circular vectors that can replicate very large pieces of DNA; used to clone pieces of human chromosomes for the Human Genome Project.

YAC

Plasmid vectors grown in yeast cells that can replicate very large pieces of DNA; used to clone pieces of human chromosomes for the Human Genome Project.

Ti vectors

Plasmid DNA vector derived from soil bacterium that can be used to clone genes in plant cells and deliver genes into plants.

Complementary DNA libraries

DNA copies of all mRNA molecules expressed in an organism′s cells; can be "screened" to isolate genes of interest.

Reverse transcriptase

Viral polymerase enzyme that copies RNA into single-stranded DNA. This commercially available enzyme is used for many molecular biology experiments, such as creating cDNA.

Retroviruses

Viruses that contain an RNA genome and use reverse transcriptase to copy RNA into DNA during the replication cycle in host cells.

DNA probe

A single-stranded radioactive or nonradioactive DNA fragment that is complementary to the gene of interest

Oligonucleotide

Short, single-stranded synthetic DNA sequences; used in PCR reactions and as DNA probes.

PCR

Laboratory technique for amplifying and cloning DNA; involves multiple cycles of denaturation, primer hybridization, and DNA polymerase synthesis of new strands.

Taq DNA polymerase

DNA-synthesizing enzyme isolated from Thermus aquaticus, a thermophilic Archae that lives in hot springs; its ability to withstand high temperatures (thermostable) without denaturation makes it valuable for use in PCR experiments.

Restriction map

An arrangement or "map" of the number, order, and types of restriction-enzyme cutting sites in a DNA molecule.

Agarose gel electrophoresis

Laboratory procedure that involves using an electrical charge to move and separate biomolecules of different sizes, such as DNA, RNA, and proteins, through a semisolid separating gel matrix. Examples include agarose gel electrophoresis and polyacrylamide gel electrophoresis (PAGE).

Ethidium bromide

Tracking dye that penetrates (intercalates) between the base pairs of DNA. Commonly used to stain DNA in gels because ethidium bromide fluoresces when exposed to ultraviolet light.

DNA sequencing

Laboratory technique for determining the nucleotide "sequence" or arrangement of A, G, T, and C nucleotides in a segment of DNA.

Dideoxyribonucleotide

modified nucleotide. A ddNTP differs from a normal deoxyribonucleotide (dNTP) because it has a hydrogen group attached to the 3′ carbon of the deoxyribose sugar instead of a hydroxyl group-OH.

Fluorescence in situ hybridization

Laboratory technique that uses single-stranded DNA or RNA probes labeled with fluorescent nucleotides to identify gene sequences in a chromosome or cell in situ (Latin for "in its original place").

Southern blotting

Laboratory technique invented by Ed Southern that involves transferring (blotting) DNA fragments onto a filter-paper blot for use in probe hybridization studies.

Northern blotting

Laboratory technique for separating RNA molecules by gel electrophoresis and transferring (blotting) RNA onto a filter paper blot for use in hybridization studies.

Western blotting

Laboratory technique for separating protein molecules by gel electrophoresis and transferring (blotting) proteins onto a filter paper blot that is usually probed with antibodies to study protein structure and function.

DNA microarray

A chip consisting of a glass microscope slide containing thousands of pieces of single-stranded DNA molecules attached to specific spots on the slide; each spot of DNA is a unique sequence.

Quantitative PCR

Uses primers made with fluorescent dyes and specialized thermal cyclers that enable researchers to quantify amplification reactions as they occur

Site-directed mutagenesis

With this technique, mutations can be created in specific nucleotides of a cloned gene contained in a vector. The gene can then be expressed in cells, which results in translation of a mutated protein. This allows researchers to study the effects of particular mutations on protein structure and functions as a way to determine what nucleotides are important for specific functions of the protein.

siRNA

Small (21 or 22 nt) double-stranded pieces of nonprotein coding RNA, so named because they were shown to bind to mRNA and subsequently block or interfere with translation of bound mRNAs.

genomics

The study of genomes.

bioinformatics

Interdisciplinary science that involves developing and applying information technology (computer hardware and software) for analyzing biological data such as DNA and protein sequences; also includes the use of computers for the analysis of molecular structures and creating databases for storing and sharing biological data.

national center for biotechnology information

formed the RAC which was charged with evaluating risks of recombinant DNA technology

GenBank

Renowned public database of DNA sequences provided by researchers throughout the world; resources for sharing and analyzing DNA sequence information.

Semiconservative replication

Process by which DNA is copied; one original (parent) DNA molecule gives rise to two molecules, each of which has one original strand and one new strand.

Helicase

Enzyme that separates two strands of a DNA molecule during DNA replication.

Single-stranded binding protein

Proteins that bind to unraveled single strands of parental DNA during DNA replication to prevent DNA from reforming double strands before being copied.

Origin of replication

Specific locations in a DNA molecule where DNA replication begins.

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