DNAHistory/Structure

https://www.youtube.com/watch?v=zwibgNGe4aY

DNA◦Nucleic Acid that stores and transmits genetic information from one generation to the next.

DNA◦Made up of units (nucleotides) which have 3 parts◦1) Deoxyribose (sugar)◦2) Phosphate group ◦3) Nitrogenous base ◦Adenine (A)◦Cytosine (C)◦Guanine (G)◦Thymine (T)

https://www.youtube.com/watch?v=qy8dk5iS1f0

DNA◦Hydrogen bonds form to hold the nitrogenous bases together◦Double Helix- shape of DNA◦Base pairing (Chargaff’s Rule)- Adenine/Thymine; Cytosine/Guanine◦C and T =pyrimidines◦A and G= purines◦DNA is located in the nucleus

ChromosomesDraw and label the this diagram on your own paper

Chromosomes contain genes which is DNA that contain instructions for assembling proteins.

ChromosomesChromosomes contain DNA and protein which together is called chromatin.

Genes, DNA and Chromosomes◦As you watch this video clip take notes on Genes, DNA and Chromosomes

https://www.youtube.com/watch?v=C8OL1MTbGpU

DNA replication Process of copying DNA

1.Involves original DNA (unzipping)enzyme called DNA polymerase2. New base pairs join to fit missing bases3. End result is 2 DNA strands that match.

As you watch this video clip answer the following questions…◦What is the replication fork?

◦What is the leading strand of DNA replication? The lagging strand?

https://www.youtube.com/watch?v=OnuspQG0Jd0

Mutations◦ https://www.youtube.com/watch?v=Jm8Y7KTDgEE

Mutations◦Any change in the DNA/gene/chromosome format from its original/intended form.

◦NOT always bad

https://www.youtube.com/watch?v=19_LxQmW0mw

https://www.youtube.com/watch?v=flGCik0MMKo

Gene mutations◦A. Point Mutations- occur at one single nucleotide in the DNA. - Substitution B. Frameshift Mutation- shift the entire DNA sequence- Deletion - Addition

Chromosomal Mutations◦Changes in the number or structure of chromosomes◦Relocation of chromosomes (oops)◦Part of the chromosome broken (oops)◦Extra copies (oops)

Mutations can affect any living organism. ◦ https://www.youtube.com/watch?v=kSqXjqIclAI

https://www.youtube.com/watch?v=bLBu57ayA8Q

Zac found this video clip

https://www.youtube.com/watch?v=O_5WfI9YCqk

Mutation movie poster

RNA/Protein Synthesis3 main differences between DNA and RNA

1)Sugar (Deoxyribose in DNA, Ribose in RNA)

2)RNA single stranded (DNA double stranded)

3)Uracil base in RNA (DNA thymine)

RNADisposable copy of DNA

3 types of RNA

1)mRNA (Messenger)- carries copies of instructions to build proteins

2)rRNA (Ribosomal)- found in ribosomes, proteins are assembled3)tRNA (Transfer)- transfers amino acids to ribosomes

https://www.youtube.com/watch?v=0Elo-zX1k8M

Protein SynthesisRNA assists in the process of translating the DNA code into RNA code and eventually into amino acids--proteins. These proteins help to determine genetic traits!

◦Process of coding DNA into RNA using RNA polymerase (mRNA)◦RNA copies DNA into a corresponding RNA strand (mRNA)◦Codes tell the RNA where to begin/end the process.

Transcription

Cracking the Code◦mRNA code has to be broken (genetic code)◦Codon- 3 nucleotides in a row that equal the code to make an amino acid◦There are 20 amino acids but 64 possible 3 letter (codon) combinations so there are repeats.

Codon chartAUG is a start codon

Translation decodes the mRNA message

◦Ribosomes help “translate” the mRNA code in the ribosome of the cell.◦tRNA has an anticodon who is looking for its codon pair◦Codons and anticodons find each other until a “stop” code is read which breaks off the polypeptide chain.

Protein Synthesis

https://www.youtube.com/watch?v=h5mJbP23Buo

Meiosis◦2 phase process◦Creates new organism◦Requires half of chromosomes from each parent◦Gametes (sex cells- sperm/egg)◦Not an exact copy◦Results in 4 haploid (2N) cells which are genetically different

https://www.youtube.com/watch?v=qCLmR9-YY7oAs you watch this video listen and define

Homologous Chromosomes-

Crossing Over-

Let’s draw and simplify this…

◦Diploid= double (2 sets of chromosomes) 2N=8 Humans have 46 chromosomes, this is the diploid number.

◦Haploid= half (1 set of chromosomes) (N) Human sex cells have 23 chromosomes each. This is the haploid number.

Meiosis I◦Chromosomes duplicate (prior) to Meiosis I◦Looks like mitosis phases (P,M,A,T)◦Chromosomes pair with their copy, this is called a tetrad (4 chromatids)

Crossing Over◦Exchange of alleles between chromosomes= results in new combinations of genes

Meiosis II◦2 cells split again resulting in 4 haploid cells

Polar bodies◦Not all of gametes become fertilized, some are basically “dumped” or reabsorbed into the body, these are polar bodies.

Multiple births◦Fraternal twins- two separate eggs, two separate sperm cells◦Identical twins- 1 egg, 1 sperm then the egg splits

https://www.youtube.com/watch?v=NROLGzrAZv0

Conjoined twins◦Egg doesn’t completely split, yet continues to grow/develop in other areas.

https://www.youtube.com/watch?v=aNQc4NziUWc

https://www.youtube.com/watch?v=VQgTwH6ijp8