DNADNA eoxyribo ucleic cid

DNA is found in the nucleus of a cell. It makes up our chromosomes. (what about prokaryotes?) It is also found in these organelles: _______________ & ________________ Chloroplasts Mitochondria Interesting Factoid: Each human cell has about 1.8 meters (5.5 feet) of DNA!

DNA Function  Controls all protein production for the body.  Controls all genetic traits.  Controls some personality traits?

The Monomer of DNA is… A Nucleotide! A nucleotide consists of: - A sugar (deoxyribose) - A Phosphate - A Nitrogenous Base (either Adenine, Guanine, Cytosine or Thymine)

Nitty Gritty on DNA  DNA is like a twisted ladder, this is called a double helix. It twists upon itself to form tight knots called histones which are found on chromosomes.  The “backbones” are made of alternating sugar (deoxyribose) & phosphates  The “rungs” are made of nitrogenous bases (A,T,C, & G)  Adenine ALWAYS goes with Thymine  Cytosine ALWAYS goes with Guanine

What happens during Interphase?  The original strand of DNA “unzips”.  Each “open” nucleotide binds to a new complimentary nucleotide.  End result is two identical strands of DNA, each half of the original and half new. Yup! Chromosomes duplicate, or make an exact copy!

ube.com/watch ?v=rpwjZX_z5r g DNA Replication YouTube Clip Replication

Protein Production DNARNAProtein

Protein Synthesis TTTThe process of making enzymes, which are catalysts and used in many life processes to build up and break down compounds. Also, structural proteins are made, which form organs and tissues.

RNA: Ribonucleic Acid AAAA nucleic acid which has only one strand. IIIIt is made from DNA, and codes for specific amino acids, the building blocks of proteins.

Ribonucleic Acid: RNA Pieces of DNA are copied onto RNA. RNA carries that information out of the nucleus and to the “job site” (which is called the _______________.) Only one gene on the DNA molecule is copied into RNA. (Even though it carries ALL information for ALL genes) Just like a cook book contains 100’s of recipes, but you use the information for just one recipe at a time. ribosome

3 Types of RNA 1.mRNA (messenger RNA): The single stranded RNA that copies the information from a portion of DNA and leaves the nucleus. three bases = codon three bases = codon 1.tRNA (transfer RNA): These are only 3 base pairs long and contain an anti-codon (the complements to a codon) and carry a single amino acid to the “production site” of the protein. 2.rRNA (ribosomal RNA): This is (obviously) found in the ribosome and helps tRNA and mRNA communicate.

Basic RNA Structure  RNA is single stranded  DNA has deoxyribose sugar, while RNA has ribose.  RNA uses Uracil instead of Thymine.  (Also, RNA can leave the nucleus. DNA CANNOT!!!!)

Transcription: The process of making messenger RNA from DNA.

Codons & Anti-Codons MUY IMPORTANTE!!! Every THREE base pairs on an RNA molecule is called a CODON. Every CODON codes for a specific amino acid. An ANTI-CODON (on tRNA) has the complementary base pairs and physically carries an individual amino acid to the ribosome.

HINT: Transcription and Translation occur in alphabetical order!! Copying a portion of DNA into a strand of RNA Converting the information on the RNA strand into a protein molecule

Translation making proteins from RNA Ribosome mRNA READ THE CODE: 1. The mRNA is “read” by the ribosome. 2.The tRNA brings the correct amino acid to the ribosome. ASSEMBLE: 3.The amino acids are linked together in the order dictated by the mRNA strand. 4.The sequence of amino acids determines the type and structure of a protein molecule.

Transcription & Translation Review ? ? ? ? Transcription Video Accurate Translation Clip Good Clip!

Translation: Amino Acid Codon Chart Ala ThrGlu LeuArg Ser STOP!

Mutations  A mutation is a spontaneous and random change in the base pair sequence of DNA.  Mutations can be caused by environmental factors such as UV light (sunshine), Nuclear Radiation and other chemicals (“carcinogens”)  Mutations can also occur due to an error while DNA replicates itself.

Mutations  Mutations passed on to offspring if in  Mutations NOT passed on if occur in gametes Somatic cells (body cells)

Types of Mutations: 1. Point Mutation: This is a random change of one base pair. In this case the A was substituted with a C. This caused Sickle Cell Anemia.

Different Mutations

Chromosome Mutations: Nondisjunction Mutation: Occurs due to an error in meiosis. Homologous chromosomes do not separate properly. Affect many genes, visible in the phenotype Down’s Syndrome: trisomy 21 4n

Edward’s Syndrome Patau’s Syndrome trisomy 13 Klinefelter’s Syndrome XXY Turner’s Syndrome XO Sex chromosome disorders: (Pair #23)

Detecting Mutations: Screening Blood samples Urine samples

Gene Expression OOOOn everyone’s chromosomes, there are many genes that are never expressed. SSSSome genes can be “turned on”(or turned off) in response to stimuli (changes in the environment). EEEExample: If a person has a gene for acquiring a type of cancer, and they smoke, the gene may be expressed. Without smoking, the gene may never be expressed.

Environment affects gene expression Chlorophyll production in the sun Himalayan rabbit fur turns black with cold Identical twins (Minnesota Twins Studies)

Changes in gene expression with environment…  Buttercup leaves underwater Above water leaves…

DNA Electrophoresis Quiz 1. cut the DNA into various size fragments. 2. The DNA pieces are loaded into a which acts like a maze. 3. An runs through the gel carrying the charged DNA through the gel. The shorter the piece, the it travels. Restriction enzymes gel electric current negatively farther

A Classic Example of Genetic Engineering Gene of interest for producing insulin is cut with restriction enzymes from a human chromosome The circular plasmid DNA of a bacteria is cut and the human insulin gene is inserted The bacteria cells produce human insulin which is collected and bottled for diabetics. In the past, insulin from sheep and cows was used, but using bacteria produces a safer form of the hormone!

Wacky Tobaccy!  This tobacco plant had genes from a firefly spliced into its chromosomes – It glows!

Cloning Cloning Cloning is taking the genetic material from an organism and creating an entirely new, exact copy. Part of the challenge is to get a cell where none of the DNA is “turned off”. video

Human Heredity experiments are not done because: 1.Small sample size 2.Long gestation 3.Immoral 4.Few offspring