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Microarry experiement

-mRNA is extracted from cell, used as a template to synthesize an artificial form of DNA called copy DNA (cDNA) marked by an indicator. -cDNA is incubated in microarry, bind to it at locations that correspond to individual genes in the cell genome. -Microarry is scanned and analyzed to compare the patterns of gene expression in each cell sample.

Chorionic villi sampling

9th week of pregnancy cells can be removed from chorion congaing fetal cells, used for karyotype.

Point mutation

A chemical change that affects one or a few nucleotides. May involve substation insertion or deletion of 1 or more nucleotides.

Gene

A functional segment of DNA that directs the production of one or more polypeptides (protein molecules). They're not spaced regularly on chrs and there's no set relationship between the # of genes in an organism and the total size of its genome.

Recombinant DNA

A molecule of DNA that includes genetic material from different sources.

Transcription

A process of copying the N base sequence in the DNA and bringing it to the ribosome where translation occurs. DNA is copied into mRNA which carries info to the protein synthesis machinery in cytoplasm. For each gene only 1 strand of the double stranded DNA is transcribed called the sense strand and the other one is the anti-sense strand. 1. DNA of a specific gene unzips. 2. mRNA nucleotides attach to exposed N bases of DNA. 3. mRNA nucleotides join together forming a single strand that detaches, leaves the nucleus and moves to the ribosome.

Codon

A set of 3 bases. One codon will code for one amino acid. The genetic code is always interpreted in mRNA codon rather then original DNA strand.

Primer

A short strand of RNA that is complementary to a DNA template and is the starting point for the attachment of new nucleotides.

Replication origin

A specific nucleotide sequence where replication starts.

Elongation

"The process of joining nucleotides to extend a new strand of DNA". DNA polymerase adds nucleotides to replication bubble on the free 3' OH end of a pre-existing chain of nucleotides to create a complementary strand of DNA. -Only takes place in the 5' to 3' direction. -A primer is the starting point for new nucleotides, which is constructed by primase.

Frederick Griffith

Noticed dead pathogenic bacteria could pass on their disease to non-pathogenic bacteria, called this the TRANSFORMING PRINCIPLE.

The replication machine

The complex polypeptides and DNA that interact at the replication fork.

Genome

The sum of all the DNA that is carried in each cell of an organism. Includes genes and regions of non-coding DNA, which may play various roles in gene expression.

Mutation

a permanent change in the genetic material of an organism. All are inheritable but not all are passed on to future generations. They're copied during DNA replication and passed on to daughter cells.

Transgenic organism

a result of importing feign DNA into plants and animals. Their genetic material has DNA from different species.

Mutagen

a substance or event that increases the rate of a mutation.

Germ-line mutations

affect genetic info in the gametes of an organism and are passed to offspring.

Silent mutation

has no effect on the cell's metabolism or the final structure or function of protein produced.

Genetic engineering

manipulating genetic material to alter genes and blend plant or animal or bacterial DNA.

Substitution

may have a minor effect, no effect, slightly altered affect but functional, or harmful one. Harmful if a start or stop signal is deleted, as it may not produce a functional protein. A substitution that affects a regulatory sequence may result in the cell being unable to respond properly to metabolic signals. Nucleotide substitutions do not effect neighbouring coding sequences. Insertion and deletion results in a frameshift mutation, causing the entire reading frame to be altered, usually resulting in a nonsense mutation.

Somatic cell mutations

occur in body cells.

Replication

process of creating an exact copy of a molecule of DNA. A cell replicates all of its DNA/it's genome only once, during S phase.

Termination

the completion of the new DNA strands and the dismantling of the replication machine.

Gene therapy

the process of changing the function of a gene in order to treat or prevent genetic disorder. This combats a disorder's genetic cause rather than its symptoms. A molecule called DNA VECTOR carries foreign DNA into target cells in the patient. Using restriction endonucleases viruses can be genetically altered to carry a desired gene which targets a certain cell and inserts that DNA in.

DNA sequencing

the process of identifying the precise nucleotide sequence of a DNA frogment.

Proteomics

the study of all proteins produced by a genome.

Genomics

the study of entire genomes, including interactions among multiple genes. Closely associated with proteomics.

Gene expression

the transfer of genetic info from DNA> RNA> Protein.

Bioremediation

the use of living cells for environmental remediation. ex. bacteria designed to clean up oil spills or remove metals from H20.

Biotechnology

the use of natural biological systems to create new technologies/products.

Somatic gene therapy

therapy aimed at correcting genetic disorders in somatic cells. It doesn't prevent it from passing to patient's children.

Amniocentesis

used to find out if a fetus is infected with a chromosomal disorder. A needle withdraws amniotic fluid placed in a nutrient rich medium where cell multiply. A karyotype/genetic analysis is done.

Germ-lined therapy

used to modify the genetic info carried in germ cells. Banned in Canada for ethical reasons.

Carcinogenic

Associated with 1+ forms of cancer.

Nucleotides

Composition of DNA, RNA. A DNA nucleotide is composed of a 5-carbon sugar (deoxyribose), a phosphate group and 1 of 4 nitrogen containing bases (ATCG). RNA has the base of Uracil instead of thymine. Nucleotides are present in varying but characteristic proportions.

Chargaff's rule

Constant relationships, amounts of Adenine=Thymine Cytosine=Guanine

Primase

Constructs the primer.

Regular genes

Control production of repressor proteins which switch off structural genes.

DNA Double Helix Structure

DNA is made up of 2 long strands of nucleotides bound together in a spiral shape called a double helix. The handrails of the ladder are the sugar-phosphate backbones of these strands. The distance between them remains constant although the nitrogenous bases are different sizes.

Transposons

Genes that can move along a chromosome.

Clones

Genetically identical organisms. Identical twins are naturals. Clones offspring suffer from high immortality rate and disease.

Lagging strand

New DNA is synthesized in short segments called Okazaki fragments which are spliced together by DNA ligase.

Exons

Parts of DNA that form the gene.

Restriction enzymes

Catalyze the cleavage of DNA at specific nucleotide sequence to defend against infection from foreign DNA.

Oncogenes

Cause cancer.

Spontaneous mutations

Caused by natural molecular interactions.

Introns

Meaningless DNA, 95% of it.

DNA polymerase

Adds nucleotides in replication bubble to create a complementary strand of DNA to the 3'OH group of an existing nucleotide. Removes RNA primer by eliminating nucleotides in the 5' to 3' direction then fills the space by extending neighbouring DNA strands. Can recognize if hydrogen bonding is taking place between the new base and its complement on the original strand. The absence of H bonding shows a mismatch of bases. DNA polymerase then removes the incorrect base from the new strand and adds the right on using the parent strand as a template.

Human Genome project

An international researcher team project in 2003 that tried to sequence the entire human genome.

DNA

Deoxyribonucleic acid. The nucleic acid molecule that governs processes of heredity in all plant & animal cells. It carries the instructions to put amino acids into sequences that make proteins. DNA is carried on chromosomes. Nucleotides are the basic building block of DNA.

Structural genes

Direct the synthesis of proteins in individual cells. Used to build cell structures or other molecules.

Purines

Double ringed! Adenine and Guanine.

Semi-conservative

Each new molecule of DNA contains 1 strand of the original complementary DNA molecule and 1 new parent strand. Each DNA molecule conserves half the original one. -DNA unzips, breaks H bonds. -New N bases are added to each half.

Helicases

Enzymes that bind to the DNA at the replication origin and unravel some of the double helix creating a replication bubble.

Phoebus Levene

Isolated RNA and DNA. Found GENES ARE LOCATED ON CHROMOSOMES. (Levvy jeans)

Frederich Mieshcer

Isolated acidic phosphorus-containing substance from the nuclei of white blood cells. Came up with the term NUCLEIC ACID.

Initiation

Replication starts at the replication origin where helicases bind to DNA and unravel a segment of the double helix. Now the unwound area is a replication bubble with each Y shape in it being a replication fork.

Mis-sense mutation

Results in an altered protein. Can be harmful or may lead to a slightly altered but functional polypeptide.

RNA

Ribonucleic acid. A nucleic acid that plays a role in gene expression and protein synthesis, shares a similar structure with DNA. It's a single strand but can fold back on itself to make regions of complementary base pairs. It can assume different structures so there's several types of RNA which each serve a certain function.

Pyrimidines

Single ringed! (a TC pyramid with a ring) Thymine and Cytosine. TC! My neighbour! Lives in a pyramid shaped house in the single ring of Canmore.

DNA ligase

Splices together Okazaki fragments. Catalyzes the formation of phosphate bonds between nucleotides.

Antiparallel

The 2 strands of DNA are not identical but compliment each other. Antiparallel means the phosphate bridges run in opposite directions in the 2 strands. Each end of a double stranded DNA molecule contains the 5' end of one strand and the 3' end of the complementary strand.

Genetic code

The order of the base pairs in a DNa molecule make it up. It determines how the amino acids are strung together and how proteins are made.

Cancer

The result of somatic cell mutations that disrupt the expression of genes.

Leading strand

The strand of DNA that is replicated continuously.

Complementary base pairs

Two nitrogen bases paired that are connected by hydrogen bonds. AHHT!! CHHHG!!! A-H-H-T C-H-H-H-G

Rosalind Franklin

Used X-rays to observe structure of DNA. Found DNA has a helical structure with 2 regularly repeating patterns. Concluded the nitrogenous bases weree located on the inside of this structure and that the sugar-phosphate was on the outside.

Alfred Hershey & Martha Chase

Used radioactive labelling protein and DNA in a bacteriophage to see which molecule was responsible for taking over the host cell. Proved that GENES ARE MADE OF DNA.

Mitochondrial DNA

Used to gather info about the history of individual species. Because the cytoplasm of a zygote is donated by the ovum, one's mtDNA is genetically identical to that of your mother and her mother.

Gel electrophoresis

Used to separate molecules according to their mass dn a charge to separate fragments of DNA. A solution with DNa fragments is put on one end of gel. Electric current is passed through gel, causing one end to become + and the other -. DNa fragments move to + end, small ones move quickly. The fragments separate into a pattern of bands called a DNA FINGERPRINT.

Protein clock theory

Uses differences in types of amino acids of the same protein in different species to determine ancestry. The greater the change in 2 proteins is the longer time they diverged.

Amino acids

What proteins are made of, discovered by Frederick Sanger. The specific sequence of amino acids determines the chemical properties of each protein. The proteins produced by a cell determine its function, structure and development. There's 20 amino acids and 64 combinations for possible codons. Includes initiator (start of protein) and terminator codon (signals finish).

Genetic markers

a characteristic that provides info about the genotype of an individual. May be found using a DNA probe which consist of a molecule of DNA with a nucleic acid sequence that is complementary to the marker sequence, marked with a chemical tag. DNA from tissue is placed in a suspension with the DNA probe. If the sample has the gene of interest the produce will bind to the marker sequence, proving the presence of a gene.

DNA microarry

a chip containing a grid of thousands of microscopic cells containing a nucleic acid sequence that can bind with one of the mRNA molecules transcribed during gene expression. It allows us to pinpoint genes responsible for certain functions or conditions, study how genes interact and relationship of environment and gene expression.

Chemical mutagens

a molecule that can enter the nucleus of a cell and induce mutations by chemically reacting with DNA. May cause a substitution or frameshift mutation. May have a similar structure to nucleotides but a different base pairing properties. They cause incorrect nucleotides to insert during DNA replication. Most are carcinogenic.

RNA polymerase

catalyzes the synthesis of RNA. -A sequence of nucleotides on the DNA molecule are a promoter region that tells it where to bind. -Once it's bonded to the sense strand it opens some of the double helix and makes a complementary strand of mRNA. -RNA polymerase works in 5' to 3' direction. -It only transcribes one strand of template DNA so it doesn't need Okazaki fragments. -A certain nucleotide sequence signals that halt of transcription, where it detaches from the DNA strand and the double helix reforms.

Induced mutations

caused by agents outside the cell.

Physical mutagens

causes physical changes in the structures of DNA. High energy radiation is the most damage mutagen known.

Translation

process of translating the mRNA N base sequence into a series of amino acids that will form a protein. A codon will code for one amino acid. tRNA picks up the different amino acids and brings them to the mRNA attached at the ribosome. tRNA has 3 N bases called an anticodon (complementary to mRNA codon) that matches up to a codon on the mRNA strand, putting the amino acid it holds in the right spot. Ribosomes bring the mRNA strand, the tRNA molecules carrying amino acids and the enzymes needed to build polypeptides together. They also contain ribosomal RNA rRNA. 1. mRNA strand attaches to active ribosome complex, 2 adjacent codons are exposed. 2. tRNA picks up amino acids. 3. tRNA and amino acids move to mRNA and base pairs with the start codon, AUG. tRNA anticodons match up with mRNA codons. 4. Amino acids bond to form a protein. 5. mRNA and trRNA break apart, mRNA returns to nucleus, tRNA to cytoplasm, protein can be used.

Restriction endonucleases

recognizes a short sequence of nucleotides (target sequence) within a strand of DNA and cut the strand at a particular point in the sequence (restriction site). Each endonucleas recognizes a different target sequence which will occur by chance in almost every fragment of DNA.

Nonsense mutation

renders the gene unable to code for a functional polypeptide. Results in a stop signal instead of a normal amino acid. Can result in a fragment of a protein.

Endosymbiont theory

says eukaryotic cells arose from one prokaryote being engulfed by another.

Ultrasounds

sound waves are sent through amniotic fluid which bounce off fetus, cross image is made and usable.