27. What occurs during: Replication- DNA making DNA Transcription- DNA making RNA
What is DNA? Nov. 5, 2013. Warm up: 1. What is DNA? 2. Why do we need to learn about it? Your...
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Transcript of What is DNA? Nov. 5, 2013. Warm up: 1. What is DNA? 2. Why do we need to learn about it? Your...
Warm up:1. What is DNA?2. Why do we need to learnabout it?
Your answers should be on the notes page. You have one minute to finish up!
Yesterday’s Exit Ticket
HOW can scientists study traits? What do they actually look at?
… Many of you said “GENES”
Can anyone tell me what a “GENE” is?!!!!
Remember Genetic Engineering?
• Genetic engineering is a technique used by scientists to change the DNA of living organisms.
Yesterday’s opinions…
20% said… SURE! Social status wouldn’t be affected much more than it already is, it will actually increase equality, it could increase our nation’s education level, HEALTHY BABIES!
12.5% said… I JUST DON’T KNOW!
AND 67.5% said… NO WAY, JOSE!Who knows the side effects down the road, technology is going too far, religious beliefs say you are made they way you are supposed to be, if you aren’t satisfied with how your baby may turn out, DON’T HAVE KIDS! (after all, they are made from YOUR genes, so what is “un-perfect” ?)
So, what is DNA then?
• DNA is a nucleic acid
• DNA stands for Deoxyribonucleic Acid
• DNA – is the genetic material inside the nucleus of
eukaryotic cells.
Remember biomolecules
IT ACTUALLY WINDS UP REALLY TIGHTLY AND FITS
INTO CHROMOSOMES!!!
IT ACTUALLY WINDS UP REALLY TIGHTLY AND FITS
INTO CHROMOSOMES!!!
Which cell organelle is DNA found in (for eukaryotes)?
Do prokaryotes even have DNA???
THE NUCLEUS!
OF COURSE! But, it is not protected by
a nucleus!
Discovering the Structure of DNA
Structure was discovered in 1953 by James Watson and Francis Crick
They were only able to complete the model after x rays taken of
DNA through a microscope by a woman named
Rosalind Franklin revealed the key to determining the true
shape….she was never officially credited with
the discovery
Watch this!:DNA ANIMATION!
What is the purpose, or function, of DNA?
• Stores the genetic information that instructs the cell on which proteins to make.
• So, DNA makes PROTEINS
(both are biomolecules!)
• Responsible for determining all organism’s traits such as eye color, body structure, and enzyme production.
Proteins are responsible for most of these
traits!
The Components of DNA• DNA is a long molecule made up
of repeating individual units of monomers called nucleotides.
– Nucleotides are made up of three parts that are held together by covalent bonds:
1. Sugar
2. Phosphate Group
3. Nitrogenous Base
Phosphate
Nitrogenous Base
DeoxyriboseSugar
In the diagram, what substance is represented by the letter x?
A. Ribose sugar
B. Deoxyribose sugar
C. Phosphate
D. Adenine
Nitrogenous Bases
• DNA contains four nitrogenous bases:1. Adenine (A)
2. Guanine (G)
3. Cytosine (C)
4. Thymine (T)
In DNA, Which Bases Pair?
• Adenine (A) always pairs with Thymine (T)
• Guanine (G) always pairs with Cytosine (C) Covalent
bonds
Watch this!: COMPOSITION OF DNA
What are Hydrogen Bonds?Hydrogen bonds are weak and
they combine the two DNA strands.
It is important that these
middle bonds are weak! Why do you think???
Structure of DNA
• Phosphate Group & Deoxyribose Sugar – Form the backbone or
sides of the ladder.
• Nitrogenous Bases – Form the “steps” of the
ladder or middle of the molecule.
X makes up the backbone along with which other molecule?
A. Ribose sugar
B. Deoxyribose sugar
C. Base-pairs
D. Adenine
G C
TA
A
A
A T
T
T
G
G
G
C
C
C
DNA of a horse DNA of a human
What is the difference?The difference is in the order of the bases.
The more alike two organisms are, the more alike their order of bases will be.
Information for everything about an organism is carried in the order of bases in their DNA, like a language.
If we all have the same components
of DNA, why do we look different
from other people and from other organisms like
horses or plants?
BUILDING A DNA MODEL:• You should have the following materials:
• 1 piece of white copy paper (watch how I fold it!)• 8 phosphates• 8 sugars• 2 adenine bases• 2 thymine bases• 2 guanine bases• 2 cytosine bases
• Use what you learned today to create a DNA model!
• Before you glue, have me check!
EXIT TICKET QUICK-WRITE:Using as much of the vocabulary below,
describe the structure and function of DNA.
deoxyribose double helix nucleotide Watson and Crick
cytosine
covalent bonds
genetic information
thymine base pair nitrogen base
phosphate 3’ to 5’ 5’ to 3’ protein synthesis
genetic code
adenine nucleus hydrogen bond
guanine traits
YOU HAVE FIVE MINUTES!