Websites for unit 8 / / online.com/Objects/ViewObject.aspx?ID=AP1302http:// online.com/Objects/ViewObject.aspx?ID=AP1302 ▫Protein synthesis animation Mr. Wannamaker’s animations ▫  Practice transcription and translation 

warm-up 10/8#28 DNA A type of Nucleic Acid which consists of two strands of nucleotides. DNA contains the genetic instructions used in the development and functioning of all known living organisms. RNA A type of Nucleic Acid which consists of one strand of nucleotides. RNA plays an active role protein synthesis. Don’t forget….. NUCLEIC acids are made of? ___________

What do you remember about nucleic acids? Watch and listen to the song about DNA and write down three NEW things you learn about DNA.

Unit 3.1 DNA Structure and Replication

A. Discovery of DNA structure Rosalind Franklin was the first to take a clear “picture” of DNA using X-ray crystallography. The “picture” offered a clue of the shape of DNA. Watson and Crick received credit for finalizing the model of DNA by using the picture taken by Franklin.

B. DNA- the Blueprint of Life DNA stands for deoxyribonucleic acid. DNA is the blueprint for life. Every living thing uses DNA as a code for making proteins which determine traits. ▫Ex: DNA contains the instructions for making the proteins (called pigments) which give your eyes color.

DNA is packaged into chromosomes (strands of DNA wrapped around proteins and coiled tightly) Chromosomes are found in the nucleus of eukaryotic cells. Prokaryotic cells have chromosome free-floating in the cytoplasm. B. DNA- the Blueprint of Life

C. Structure of the DNA molecule DNA is composed of two strand that are twisted together in a double helix. A double helix is a twisted ladder. The building blocks of DNA are called nucleotides. A nucleotide consists of three parts: ▫A sugar (named deoxyribose). ▫A phosphate group. ▫A nitrogen base. There are four possible nitrogen bases in a DNA molecule:  Adenine (A)Thymine (T)  Guanine (G)Cytosine (C)

C. Structure of the DNA molecule The sides of the ladder are made of sugar and phosphate. The rungs of the ladder are the nitrogen base pairs. Complementary base pairing of DNA results in the nitrogen bases always pairing up A-T and C-G. The two strands are held together by weak hydrogen bonds, between the nitrogen bases. Hydrogen Bond

Warm-upOct.9 th #29 DNA Replication Before a cell can divide, the DNA must be replicated or copied. The double helix is “unzipped” and the nucleotides are base paired. The two new strands are each ½ old and ½ new.

Structure of DNA

D. DNA Replication If I started as one cell, how did all of my cells get a copy of DNA? Because DNA is so important, when a cell divides, it must pass on an exact copy of the DNA to its daughter cells so they can function. Therefore, DNA is copied (replicated) during interphase, (specifically the “S”-phase), immediately before the cell begins mitosis.

E. Process of DNA Replication 1.An enzyme breaks the hydrogen bonds between the paired nitrogen bases. This allows DNA to “unzip” as the two strands move apart. 2.The newly unpaired nucleotides are paired (A-T and G-C) with extra nucleotides present in the nucleus. This process is catalyzed by another enzyme.

3. Enzymes then link the nucleotides along the newly constructed side of the DNA ladder by bonding sugar to phosphate backbone. 4. The DNA is proofread by enzymes for any errors. E. Process of DNA Replication

F. Result of DNA replication Two identical DNA molecules have been produced. Each “daughter” DNA molecule is composed of one “old” strand and one “new” strand (semi- conservative). Each copy of DNA is packaged as a chromatid on a doubled chromosome. After mitosis, each daughter cell will receive one of the two copies of DNA. This happens when the doubled chromosome is split.

BONUS: What if replication goes wrong? Find out two things that can happen as a result EXPLAIN your findings in space on pg. 3B below number 16

Ticket out the door 1.What type of organic molecule is DNA? 2.List the three parts of a nucleotide. 3.What is the complement (matching nitrogen base) for the following sequence of DNA. A - ____ G - ____ T – ____ C - ____ABC 4.Place the lettered pictures for DNA replication in the correct order 5. When does DNA Replication take place?

3.2 Protein Synthesis

warm-up Oct. 12 th # 30 Gene A section of DNA that codes for a specific protein. The information must be sent from the DNA to the protein, so each gene is transcribed onto mRNA. Chromosome An organized structure of DNA and protein that is found in cells. It is a single piece of coiled DNA containing many genes

3. 2 Protein synthesis A. Importance of Protein Synthesis Every inherited trait is controlled by one or more proteins. Each cell must produce different proteins, based on the function of that cell. ▫Ex: Only blood cells need to produce the protein hemoglobin. Hemoglobin

B. Protein Synthesis Requires RNA There are 3 types: mRNA (messenger), tRNA (transfer), and rRNA (ribosomal). RNA is made up of a single strand of nucleotides. The nucleotides consist of: sugar (ribose), phosphate, and a nitrogen base. ▫In RNA Uracil replaces Thymine. ▫Thus: A pairs with U and G pairs with C

A codon is every three bases in a sequence of mRNA. An anticodon is three bases on tRNA.

C. DNA Controls the Production of Proteins. A section of DNA, called a gene, it is used as the blueprint for making a protein. Each gene is composed of a specific sequence of nucleotides. ▫Ex: DNA sequence of insulin  CCA- TAG-CAC-GTT-ACA-ACG-TGA The cell knows what protein to make based on the sequence. Therefore the order of the bases matter!

D. The Central Dogma- describes the sequence in which information is passed to express your traits (controlled by protein). DNA  RNA  Protein (Transcription) (Translation)

E. Process of protein synthesis (two steps) Step 1: Transcription Occurs in the nucleus. The purpose is to rewrite the DNA code as mRNA. DNA cannot leave the nucleus (it is far too big) to go the ribosomes where proteins are made.

Step 1: Transcription Steps: 1. Enzymes unzip a section of DNA (a gene). One gene makes one protein. 2. mRNA nucleotides use one side of DNA as a template and base pair. (A-U and C-G) 3. mRNA is completed and re-zip the DNA. 4. mRNA leaves the nucleus thru a pore in the nuclear membrane. The code is complete now we need to translate!

Step 2: Translation Occurs in the ribosome. Use mRNA to build the protein. The ribosome holds mRNA in place and helps link amino acids together to make a protein.

Steps: 1. The mRNA enters the ribosome. (A “start” codon begins the process) 2. Then tRNA (transfer RNA) carries an amino acid to the ribosome 3. tRNA’s anticodon bonds with codon on the mRNA.

4. Each new tRNA transfers its amino acid to the previous one to create an amino acid chain. 5. When the “stop” codon is reached the mRNA and amino acid chain are released. The amino acid chain “folds” into its special shape and the protein is complete. When working on problems we use the “mRNA” codon to find the corresponding acid.

Warm-up Oct. 15 th #31 Transcription- use your notes to explain Translation- use your notes to explain Codon- What is a codon and what does it code for? Anticodon- What is anticodon and what does it do?

mRNA From nucleus to cytoplasm DNA transcription nucleus cytoplasm translation trait protein

From gene to protein transcription translation protein

Practice – use chart on pg.3F DNA- CGC ACC CAG ATT mRNA- Amino acids- tRNA-

4. Gene regulation All of an organism’s cells have the same DNA, but cells differ based on the expression of the genes. Gene regulation is the process which determines which genes will be expressed (used to make a protein). Different types of cells expressing different genes leads to cell specialization. ▫Ex: Muscle cells, skin cells, and nerve cells have very different functions but the same DNA. It depends on which genes are “turned on”.

G. Mutations Occurs due to a mistake during replication or protein synthesis. Results: necessary protein is not made or is defective. Two types of gene mutations: 1. Point mutations occur when a single base is replaced with a different base. May result in the change of a single amino acid within the protein Ex. Sickle Cell Anemia, GAT-TAC-A  GAG-TAC-A

2. Frameshift mutations occur when a single base is added or deleted to the sequence. The earlier in the gene sequence the base is added or deleted; the more amino acids will be changed. Ex. Huntington’s Disease is caused by the insertion of several bases. GAT-TAC-ATT  GAT-TAA-CAT-T It's caused by mutations in the huntingtin gene, which lead to the build-up of damaging proteins in brain cells

Protein Synthesis Lab Step 1 has been completed for you When you begin transcription the DNA is read starting at the side where you the number 1 DO NOT TAPE the mRNA to the DNA, tape the mRNA pieces together in a long strip

Ticket out the Door 1.Transcription occurs in _______. Translation occurs in ______. 2.After the mRNA has copied the gene sequence from the DNA what is the next step in protein synthesis? 3.What type of RNA carries amino acids to the ribosome. 4.What type of mutation occurred in the following sequence… AAT CGC TAG AAT CCC TAG

Warm-upOct. 16 th #32 Point Mutation a single nitrogen base is replaced with a different base. Example: ▫Original DNA  ACT TCA ▫Mutated DNA  ACA TCA  Frameshift Mutation  a single nitrogen base is added or deleted within the sequence.  Example:  Orginal DNA  ACT TCA  Mutated DNA  ACT ATC A---- base added OR ACT CA base deleted

Protein synthesis video clip gkPEAo