DNA

DNA

Deoxyribonucleic Acid

UNIT 5: Chapter 12

AIM:

•Explain how the genetic code is contained within

DNA.

Organizational Level of Genetics

Define these terms:

Histones-

Nucleosome-

Chromosome

Supercoils

Coils

Nucleosome

Histones

DNA

double

helix

Interesting Facts About DNA

• DNA is used to solve many historical mysteries

• One single cell contains two meters of DNA.

• If you unraveled all your chromosomes from all of your cells and laid out the DNA end to end, the strands would stretch from the Earth to the Moon about 6,000 times.

http://www.indiana.edu/~ensiweb/connections/genetics/dna.mes.pdf (DNA nitrogenous base message)

http://www.johnkyrk.com/DNAanatomy.html

(DNA animation)

http://www.genome.gov/page.cfm?pageID=10002096

(genetics library)

What is the function (job) of DNA?

Passed down to us from our parents. DNA stores the CODE for directing the

construction of proteins within a cell. These proteins determine the phenotype of an organism.

Recall, DNA is a nucleic acid—A MACROMOLECULE.

DNA Structure

DNA is a double helix (spiral) that resembles a ladder.

DNA is made up of 3 things:

1. Phosphate 2. Deoxyribose (sugar,

yes, sugar) 3. Nitrogenous Bases

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DNA structure

Hydrogen bonds

Nucleotide

Sugar-phosphate backbone

Key

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Nucleotide

Remember

DNA is like an Oreo

Phophates + sugars = cookieBases = cream filling

How is the DNA code read?

There are 4 nitrogenous bases (molecules):

1. Adenine (A)

2. Thymine (T)

3. Cytosine (C)

4. Guanine (G)

DNA bases are complimentary

BASE PAIRING RULE:

__________________________

(A) (T)

ADENINE ----------------- THYMINE

(C) (G)

CYTOSINE -------------- GUANINE

DNA Youtube Video

• http://www.youtube.com/watch?v=qy8dk5iS1f0

2 Groups of BasesPurines Pyrimidines

Adenine Guanine Cytosine Thymine

Phosphate group Deoxyribose

MODE 1:

Find the complementary base sequence for the following DNA strand:

Strand 1:Strand 2: ACTTTACTTTACCGGGGG Strand 1: CGTGTGGAAATCGGTTGAStrand 2:

Remember

DNA is like an Oreo

Phophates + sugars = cookiesBases = cream filling

Why are some people better at sports than others?

• http://www.pubinfo.vcu.edu/secretsofthesequence/playlist_frame.asp

• Gene called ACE

Who has healthier DNA, one is exercises of a couch potato?

• http://www.wwaytv3.com/video/study_lack_of_exercise_hurts_dna/01

Check out the video.

M phase

G2 phase

S phase

G1 phase

Figure 10–4 The Cell CycleSection 10-2

DISEASES

Can be caused by 2 things:

1. The environment that surrounds you.

2. Your genes.

http://www.youtube.com/watch?v=kBfWybm0218&feature=related

(vytorin commercial)

Promoter Start signal

Gene Stop signal

Gene Sequence

Section 14-3

Locating GenesHow do scientists locate genes on DNA? Why is this important?

Scientists can locate genes by looking at DNA base sequence. IdentificationOf gene location is important for benefits of medicine and curing diseases.

Examples of Genetic Diseases

• Pg. 345 in Prentice Hall hardcover/online

DNA Technology• Forensic identification is an example of the application of DNA

technology.

• There is great potential for the development of useful products through genetic engineering (e.g., human growth hormone, insulin, and resistant fruits and vegetables).

• Eugenics, a pseudo-science of selective procreation, was a movement throughout the twentieth century, worldwide as well as in Virginia, that demonstrated a misuse of the principles of heredity.

• The Human Genome Project is a collaborative effort to map the

entire gene sequence of organisms. This information will be useful in detection, prevention, and treatment of many genetic diseases.

• PCR, electrophoresis, cloning are also examples.

Chapter Review (DNA)

• What is the function of DNA?

• What does DNA need to be copied (replicated)? What phase of the cell cycle does a cell make more DNA? (G1, S, G2 or M phase)

• How is the DNA code read?

• What are the 4 nitrogenous bases?

• What are 3 components of DNA?