How does DNA map out your life? DNA and RNA How does DNA map out your life?

Warm Up 2/22/12 Cells are the smallest unit of ________________? Your nucleus is where your ___________ is located. The four characteristics of living things are: Describe the difference between unicellular and multi-cellular organisms. ________________ is another word for cell division. It only takes place in prokaryotic cells.

Announcements If you did not make an 80% or better on your tests, come to retake them! You may come in cougar time or afterschool. Tutoring will take place on Tuesday from 4:30-5:30. If you are staying to re-take a test, you MUST be prepared to take it. Study before you show up because I will be leaving promptly at 5:30.

Quick recap Based on what we talked about last week, complete the following sentences. You may look over your notes to refresh your memory. Traits are passed on through _______________. In sexual reproduction, offspring get half of their genes from each _________________. Traits pass from parents to _________________. Complete a pair share, where kids check with a partner in some cases.

Answers Traits are passed on through genes. In sexual reproduction, offspring get half of their genes from each parent. Traits pass from parents to offspring/children.

Main idea: DNA Think of DNA like a recipe or instruction manual. It is the instructions necessary for making cell parts. So, how does it do this?

Proteins In order to know about DNA, you first need to know what proteins are. Proteins are large molecules that are made up of chains of amino acids. 20 different amino acids come together to create thousands of different proteins found in the human body.

What do we use proteins for? Building cell parts Repairing damage to the body Fighting disease Regulating the speed of chemical reactions in the body (enzymes).

How does this relate to DNA? DNA stores the information that cells need to make sure they put together the amino acids in the right order. The order must be correct in order to make proteins. In other words, if DNA didn’t tell your cells how to put amino acids together to manufacture proteins, your Endoplasmic reticulum, Ribosome and Golgi bodies couldn’t do their jobs. Then the cell couldn’t maintain homeostasis.

DNA and the Genetic Code The DNA molecule takes the shape of double-stranded spiral. (It looks like a twisted ladder). Nucleotides are subunits that make up each of the two strands of DNA molecules. Nucleotides form base pairs that attach to one another in order to make up the ladder.

DNA Base Pairs

Nucleotides are identified by bases Adenine (A) Thymine (T) Cytosine (C) Guanine (G) A always pairs with T C always pairs with G These base pairs fit together like pieces in a puzzle.

To remember…. Think of the phrase “All Tigers Can Growl” A-T, C-G

Why is sequencing important? The order of bases in a strand forms the code for making proteins. Think of the bases like ingredients in a recipe. They order in which you add them determines how the food or DNA is made. 4 bases code for 20 amino acids. A code of 2 bases to 1 amino acid gives only 16 possible combinations. 3 bases to 1 amino acids gives 64 possible combinations.

To refresh your memory A gene is the entire sequence of bases that codes fir all amino acids in a protein.

Replication During replication DNA strands are as templates used to make copies of new strands. Here is how it happens: The DNA molecule opens up, separating into two strands. Nucleotides match up and join to the open DNA strands. Two identical DNA molecules are formed.

Guided Practice:P1 Turn to Page C137 and C138. Draw the diagram labeled replication at the bottom of the page. Make sure you label it. You have 10 minutes. Hint: replication means to “repeat” This is worth 25pts.

Guided Practice P2 With a partner, answer the following question Describe the differences among DNA, genes and Chromosomes. How are they related?

Answers: Genes are units of heredity that are located in DNA. DNA-molecules that stores information (about your genetic make up) Chromosomes- this is the form that DNA takes when cells divide. (DNA coils up into chromosomes)

Independent Practice Describe the shape of the DNA molecule and how the nucleotide bases fit into that structure. What is a protein and what is it made of?

Warm Up 2/23/12 What is a gene? What is a chromosome? What is DNA? How are the 3 related. Create an analogy to describe #4. What is protein and what is it made up of?

Announcements Come retake microbiology unit tests! Be sure to check my website for extra credit opportunities and complete them.

RNA In order to make proteins DNA needs help “translating” the genetic code using another molecule. RNA carries information from DNA to a ribosome where the amino acids are brought together to form a protein. The only difference between RNA and DNA is the sugars that make them. RNA-ribose, DNA-deoxyribose.

Types of RNA There are 3 different types of RNA that are used to make proteins. Messenger RNA (mRNA) Ribosomal RNA(rRNA) Transfer RNA (tRNA) In prokaryotes- RNA and protein is made in the cytoplasm. In eukaryotes-DNA is copied in the nucleus, then RNA moves to the cytoplasm, where proteins are made.

Transcription The process of transferring information from DNA to RNA. The structure is very similar to DNA. They have 4 base pairs just like DNA. The 3 bases that make up DNA are the same: Adenine (A), Guanine (G), Cytosine (C). The fourth base is different- Uracil (U) instead of Thymine.

How transcription takes place During transcription, DNA is used as a template to make RNA. DNA opens up along a gene. Nucleotides of RNA match up and join to open up the DNA strand. The completed RNA strand is released and moves into the cytoplasm. Only one strand of DNA is transcribed. So only one new RNA strand is made

Translation Ribosomes attach to an mRNA molecule at the beginning of a coding region. Transfer RNA (tRNA) match up and joins to the mRNA strand. As the ribosome moves along the mRNA strnd, it attaches one amino acid to another. tRNA molecule is released after the amino acid has been attached. Once the ribosome reaches the end of the coding region, a completed chain of amino acids are released.

Guided Practice Identify 3 types of RNA involved in protein synthesis. What might happen if the wrong amino acid is put on a tRNA molecule?

Guided Practice Protein Based on the video clip answer the following questions: Give 2 examples of protein being used by the body. How can a lack of protein prevent someone from being able to maintain homeostasis? Do athletes need more protein than others? Why or why not. How does RNA work to help the body to build more proteins.

Warm Up 2/29/12 List the base pairs of DNA. “All tigers can growl” describes what? Describe how amino acids, proteins and genes are related. (There is a hint on the board) What can you compare DNA to within the cell?

Announcements Be sure to retake your tests if you have not already. Check the bin AT THE END OF CLASS. Its contents will go in the trash at 4:15 today. Don’t ask me where your stuff is if you left it here. I will not be here on Monday (science flex day). No tutoring afterschool.

DNA pre-lab questions How does transcription begin? What happens during transcription? What happens during translation?

Behavior Warning: If you do not behave complete the alternate assignment on the board. It will be a TEST grade!

Copy the table in your notebook Label the top of your notebook properties and observations. Properties of DNA Observations

Observations What did you observe when you extracted the DNA? Where is the DNA located in a wheat germ cell? Why did we need detergent in the experiment? What does detergent do for greasy dishes? What would happen if the wheat germ and detergent were not mixed properly?

Conclusions What would happen if you toasted the wheat germ? Would the experiment work the same? Why or why not? Would DNA from a single cell be visible to the naked eye? The lab we just did is used by scientists to obtain DNA. Give some real world examples of how DNA is used in the world. Why is it useful?