DNAHistory, Components, Function, Replication, & Biotechnology

Nancy DowJill Hansen

Tammy Stundon

September 29, 2012Gulf Coast State College Panhandle Area Educational Consortium

5230 West Highway 98 753 West Boulevard

Panama City, Florida 32401 Chipley, Florida 32428

850-769-1551 877-873-7232

www.gulfcoast.edu

Biology Partnership

(A Teacher Quality Grant)

Pre-testQ and A boardWhat is DNA?

How do we use DNA?

Does everything have the same DNA?What is alike and what is different about it?

Florida Next Generation Sunshine State Standards

SC.912.L.16.3 Describe the basic process of DNA replication and how it relates to the transmission and conservation of the genetic information.

Also Assesses SC.912.L.16.4 Explain how mutations in the DNA sequence mayor may not result in phenotypic change. Explain how mutations in gametes may result in phenotypic changes in offspring. (will begin today but will define phenotype until the genetics session)

SC.912.L.16.5 Explain the basic processes of transcription and

translation, and how they result in the expression of genes. (next session)

SC.912.L.16.9 Explain how and why the genetic code is universal

and is common to almost all organisms

Florida Next Generation Sunshine State Standards

Benchmark Clarifications•Students will describe the process of DNA replication and/or its role in the transmission and conservation of genetic information.•Students will describe gene and chromosomal mutations in the DNA sequence.•Students will explain how gene and chromosomal mutations may or may not result in a phenotypic change.•Students will explain the basic processes of transcription and/or•translation, and their roles in the expression of genes.

Florida Next Generation Sunshine State Standards

Clarifications•Students will explain that the basic components of DNA areuniversal in organisms.•Students will explain how similarities in the genetic codes oforganisms are due to common ancestry and the process of inheritance.

Content Limits Items requiring the analysis of base pairs for gene mutations are meiosis.•Items will not require memorization of specific conditions resulting rom chromosomal mutations.•Items may refer to the process of meiosis in the context of mutations but will not assess meiosis in isolation

Florida Next Generation Sunshine State Standards

SC.912.L.16.10 Evaluate the impact of biotechnology on the individual, society and the environment, including medical and ethical issues. Clarification•Students will evaluate examples and/or explain the possible impact of biotechnology on the individual, society, and/or the environment.Content Limits •Items may assess current issues but will not require knowledge of specific biotechnologies or specific medical issues.•Items assessing the possible impacts of biotechnology will not assess monetary impacts.

Carbon molecule needs how many bonds

to be stable?

Macromolecules1.Carbohydrates2.Proteins3.Nucleic Acids• Functions• Examples

What is the easiest bond to break?

Bell Ringe

r

ATGC

DNA stands for deoxyribonucleic acid.

DNA double helixes are organized into 23 pairs of chromosomes in every cell in your

body.

This set of chromosomes is the instruction manual to make YOU.

Each different instruction is called a gene.

The gene instructions are written in a DNA code – the genetic code.

New coded copies are made when the DNA double helix unzips down the middle.

We have to clearly distinguish for the

kids various terms that involve DNA Chromatin

Chromatid

Sister Chromatid

Chromosome

DNA into Chromosomes-I show this at least twice (start and end) with no volume

Human Onion

Newt

Fruit fly

Amoeba

BACTERIA

ARCHAEA

PROTISTS

PLANTS

FUNGI

ANIMALS

DNA HELPS TO SHOWEVOLUTIONARY

RELATIONSHIPS OF ORGANISMS

Watson and Crick, on the right determined in the 1950’s that DNA was a “Double Helix’ that was twisted. Watson later led the work on the human genome project.

Dr. Watson's Funny Story

• Watson and Crick’s discovery built on the work of Rosalind Franklin and Erwin Chargaff.

– Franklin’s x-ray images suggested that DNA was a double helix of even width.

– Chargaff’s rules stated that A=T and C=G.

GENOMEAn organism’s complete set of DNA. In eukaryotes, this information can be found in the nucleus of virtually every cell.

CHROMOSOMEOne or more unique pieces ofDNA—circular in prokaryotes, linear in eukaryotes—that together make up an organism's genome. Chromosomes vary in length and can consist of hundreds of millions of base pairs.

GENEA specific sequence of DNA,on average about 3,000 bases long, that contains the information necessary to produce all or part of a protein molecule.

Humans have 23 unique chromosomes and we have two copies of each: one from our mother and one from our father, for a total of 46).

Eukaryotic cellNucleus

FROM GENOME TO GENE

Protein

Protein production

• DNA is made up of nucleotides

• Nucleotides are made up of:– Phosphate– Sugar– Nitrogenous base – the base can vary

4 Nitrogenous basesFound in DNA -Adenine (A) -Thymine (T) -Cytosine (C) -Guanine (G)

DNA structure

Every living thing has the SAME 4 bases!

Every 3 bases = a code = amino acid!

• The nitrogen containing bases are the only difference in the four nucleotides.

• The two strands are connected by hydrogen bonds between the nitrogen bases

• Nitrogen bases combine in a particular way

-A combines with T-G combines with C

DNA structureComplementary Base Pairing (Base Pair Rule)

•DNA is double stranded.

•The two chains or strands of nucleotides twist around one another.

DNA structure

Note: chromatids vs sister chromatids

CANDY DNA

Put to test what you have learned!

DNA Origami

The DNA inside the nucleus controls the production of proteins.

Where does protein synthesis occur?- ribosomes in cytoplasm and

rough ERHow does information from the nucleus get into the cytoplasm so that protein synthesis can occur?

-RNA

What happens to DNA ?

DNA (replication- once in every cell cycle)

DNA (TRANSCRIPTION)

RNA

(TRANSLATION)

Proteins

What happens to DNA ?

DNA replication-- DNA duplicates itself during interphase of cell cycle- S stage of Interphase (in nucleus) - Chromatin Chromatids replication strands (sister chromatids)

- “normal functions” of the cell stop - Steps of cell division follow

(More info in a session this fall) transcription & translation – Steps of protein synthesis (next session!)- during G1 of interphase

What happens to DNA ?

• DNA molecule uncoils and unzips (DNA Polymerase) – Nucleotides are fit into place on each of the parent strand

– Corrects base pair errors too

• Each parent strand is a template to form a complementary strand

• Each THREE base pairs is the DNA’s Code

DNA Replication

DNA Replication Yield:–2 double stranded DNA molecules identical to each other

–Half of each double helix is new (daughter strand) and half is the original (parent strand)

DNA Replication

DNA Replication

DNA replication

Mistakes. . . . .• Parent strands act as templates, so mistakes during replication are minimized

• Each cell has repair enzymes that repair the damage

• An error that persists is a mutation

Mistakes. . . . .OOOPS!. . . .estimated that one error is made for every 2x109 nucleotides

DNA replicationBUT. . .

Human cells contains 46 chromosomes consisting of 3 billion base pairs

. . . . .that averages to five errors per cell!!!!

Damage to the DNA code can cause changes to protein production

TYPES OF MUTATIONS

BASE-PAIR SUBSTITUTION

BASE-PAIR INSERTION

BASE-PAIR

DELETION

GENE DELETION

GENE RELOCATION

GENE DUPLICATION

NormalDNAmRNANormalprotein

DNA

mRNAMutatedprotein

DNA

mRNAMutatedprotein

DNAmRNAMutatedprotein

POINT MUTATIONS CHROMOSOMALABERRATIONS

Normal chromosome

Gene 2

Gene 1

Gene 3

Gene 1

Gene 3

Gene 2

Gene 3

Gene 2

Gene 3

Gene 2DELETED

Gene 1 RELOCATED to a different chromosome

Gene 1DUPLICATED

Insertions and deletions can be much more harmful than substitutions because they can alter the reading frame for the rest of the gene.

In point mutations, one base pair is changed, whereas in chromosomal aberrations, entire sections of a chromosome are altered.

Some mutations are harmless, some beneficial, others are neutral, others can be detrimental or fatal to the organism.

Mutations on DNA can be the result of various causes (UV

rays, radiation, chemicals like nicotine) or can be

spontaneous.

15 min

utes!!

DNA Extraction

The DNA precipitate!

or coffee filter

When DNA is a detective ...

An introduction into biotechnology… will go into more detail over various techniques in future sessions

•Genetic engineering –def: use of technology to alter the genes of viruses, bacteria, and other cells for medical or industrial purposes to better the quality of life

–Altering genes of unicellular organisms and plants and animals

Biotechnology

Genetic engineering? A firefly gene inserted into other organisms.

TOBACCO PLANT

MICE

MUSHROOMS

Recombinant DNA (rDNA) Technology

Ex. Human genes can be spliced into the DNA of bacteria to produce insulin

Combination of genes from 2 different organisms

• bacteria that eat oil are engineered to do better

• recombinant bacteria used to extract copper, uranium, gold from low-grade sources

• recombinant bacteria used to extract sulfur from coal before it is burned

More rDNA:Manipulating the DNA of

bacteria

• DNA extracted from blood and sperm can be cut by restriction enzymes– enzyme cuts at a particular base sequence

– since everyone’s DNA is different, different lengths of DNA are created when you use the same restriction enzyme on different DNA

DNA fingerprinting

Person 1: ACTGTGTGTATGGGATGTGACACACTTCCTCACTGTCATACCCTACACTGTGTGAAGG

Person 2: ACTGTGTGATGTGACACACTACGGGTTCCTCACTGTCTACACTGTGTGATGCCCAAGG

Bt CORNBacterium (Bacillus thuringiensis)

Bt crystal gene

Corn genomePlant cell

Bt crystals—toxic to insect pests—are now produced by the corn plantitself, reducing the amount ofpesticides the farmer must use.

Bacterial gene coding for Btcrystals, which are poisonous tothe insect pests, is inserteddirectly into the corn plant’s DNA.

Corn plant destroyedby insect pests

1 2 3

Manipulating the DNA

GOLDEN RICE

Genes in the pathway forbeta-carotene productionare introduced into thewhite rice genome.

Almost 10% of the world’s people suffer from vitamin A deficiencies—leading to 250,00 cases of blindness each year. The addition of beta-carotene-producing genes to white rice has increased its vitamin A content almost 25-fold.

Daffodil Bacteria

White rice

Beta-carotene

Golden rice

Manipulating the

DNA

GENETICALLY MODIFIED CROPS IN THE UNITED STATES

Proportion of crops that are not genetically modifiedProportion of crops that are genetically modified

Corn Cotton Soybeans

55% 45% 76%24% 15%85%

Manipulating the DNA

Commonly called GM Foods

rDNA of animalsCloning - produce a copy of a gene

Organ Transplant - across speciesGene Therapy – insert a missing piece of DNA to cure a person of a disease.

Other types/examples of Biotechnology

More in other sessions!

HUMAN GENOME PROJECT & DVD

Caught by a Kiss!

Crime Scene

Using enzyme amylase

Isolate DNA evidence from saliva

Forensic Science!

Ready to use what you know in the ‘real world’?

Dr. Watson explaining base pairing National DNA teaching Day

DNA interactive

DDC Education CenterFamily portrait interactiveBeaded DNA braceletOrigami DNA double Helix

The Double Helix Game

Mission Biotech virtual gaming

Pompe Disease

Follow up

•Q & A

•Post Test