intro to dna structure- inquiry modeling
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Intro to DNA structure- Inquiry Modeling. 1. What is the circled object called?. 2. What is the function (job) of the circled object?. - PowerPoint PPT PresentationTRANSCRIPT
INTRO TO DNA STRUCTURE- INQUIRY MODELING
BELLWORK
1. What is the circled object called?
2. What is the function (job) of the circled object?
3. Describe TWO ways that the structure of the circled object help it perform its function? (Hint: How does the shape, size, texture, etc. help it perform its job?)
STRUCTURE IS RELATED TO FUNCTION!
SOME FUNCTIONS ARE OBVIOUS
…BUT SOME ARE NOT SO OBVIOUS!
Fennec Fox
Sahara Desert (in Africa)
Arctic Fox
Near the North Pole (parts of Alaska, Canada, Russia, etc.)
LARGE-EARED DESERT ANIMALS
Long-eared Jerboa (deserts in Asia)
Jack rabbit (you can find them in our
Sonoran desert!)
African Elephant
COULD YOU SEE THE ACTUAL STRUCTURE OF DNA UNDER THE MICROSCOPE?
SO IN ORDER TO FIGURE OUT DNA’S FUNCTIONS, WE NEED TO
KNOW ITS STRUCTURE
HOW DO WE DETERMINE SOMETHING’S STRUCTURE IF IT’S TOO SMALL TO SEE?
…We use MODELS!
GRAB A PAPER CUP WITH YOUR PARTNER (1) & GO FILL IT WITH A VARIETY OF MODELING MATERIALS
(3 MINUTES)
DNA is a polymer (a long, chain-like molecule)
The chain is made up of small subunits
The subunits are attached to each other by covalent (very strong) bonds
There are four different, but very similar kinds of subunits
1. Draw a labeled sketch of your model and answer the questions for part 1
INFORMATION
DNA is a polymer (a long, chain-like molecule)The chain is made up of small subunitsThe subunits are attached to each other by covalent (very strong) bondsThere are four different, but very similar kinds of subunits
DNA is made of TWO long chains of subunits
These two chains are twisted around each other to form a “double helix” (a helix is the shape a pipe cleaner would be if you wrapped it around a pencil and took it off)
The diameter of the double helix is uniform (the same) along the entire length
2. Draw a revised sketch of your model and answer the questions for part 2.
The order of the subunits on one strand of
DNA, determines the order of subunits on the other strand of DNA
3. Make a labeled sketch of the order of subunits on each chain and answer the questions for part 3.
DNA is made of TWO long chains of subunitsThese two chains are twisted around each other to form a “double helix” (a helix is the
shape a pipe cleaner would be if you wrapped it around a pencil and took it off)The diameter of the double helix is uniform (the same) along the entire length
The subunits on opposite strands bind together according to these rules of complementary pairing:
Adenine (A) only binds to Thymine (T)Guanine (G) only binds to Cytosine (C)
The bonds that hold the two strands together are hydrogen bonds, which are much weaker than covalent bonds
4. Sketch your model and label the where the A,T,G & C subunits are. Answer the Qs for part 4.
The order of the subunits on one strand of DNA, determines the order of subunits on the other strand of DNA
CLOSURE1. Summarize the structure of DNA in 12
words or less
2. What are the 2 important functions of DNA you learned about today?
3. Why couldn’t we see DNA’s structure under the microscope?