DNA: life's code

75

description

DNA: life's code. =. DNA KEY TERMS. DNA NITROGEN BASE NUCLEOTIDE REPLICATION SYNTHESIS RNA DOUBLE HELIX MUTATION POINT MUTATION FRAMESHIFT MUTATION CHROMOSOMAL MUTATION TRANSLOCATION. CLONES FRATERNAL TWINS IDENTICAL TWINS TRANSCRIPTION TRANSLATION PROTEIN PROTEIN SYNTHESIS - PowerPoint PPT Presentation

Transcript of DNA: life's code

DNA KEY TERMS• DNA• NITROGEN BASE• NUCLEOTIDE• REPLICATION• SYNTHESIS• RNA• DOUBLE HELIX• MUTATION• POINT MUTATION• FRAMESHIFT MUTATION• CHROMOSOMAL MUTATION• TRANSLOCATION

• CLONES• FRATERNAL TWINS• IDENTICAL TWINS• TRANSCRIPTION• TRANSLATION• PROTEIN• PROTEIN SYNTHESIS• INTERPHASE• SEMI-CONSERVATIVE

REPLICATION

DNA ANCHORS AND BENCHMARKS

• Describe how the process of DNA replication results in the transmission and/or conservation of genetic information.

• Explain the functional relationships between DNA, genes, alleles, and chromosomes and their roles in inheritance.

• Describe how the processes of transcription are similar in all organisms.

• Describe how genetic mutations alter the DNA sequence and may or may not affect phenotype, (e.g.: silent, nonsense, frameshift)

• Explain how genetic engineering has impacted the fields of medicine, forensics, and agriculture (e.g., selective breeding, gene splicing, cloning, genetically modified organisms, gene therapy).

Process Box-Type 1

Why do we use models? Explain at least TWO purposes of models.

Model Making Activity and Question Sheet

Process Box-Type 1Recall the models of DNA you made. List the following:3 parts that were included in your model1.2.3.2 types of bonds1.2.2 rules/’laws’ of the “N’s”.1.2.1 thing you learned about DNA other than what is above.1.

DNA makes up genes that determines the ______ of all living things….such as:

traits

Eye color, skin color, texture, freckles, hair color, style…etc

DNA =

Deoxyribo-Nucleic Acid

Makes up _____________

Controls ____________

Forms _______________________

Found in the __________ of all cells

GENES

TRAITS

CHROMOSOMES

NUCLEUS

DNA is composed of four types of NUCLEOTIDES.

• DNA is made up of a long chain of nucleotides.• Each nucleotide has three parts.

1) a phosphate group2) a deoxyribose sugar3) a nitrogen-containing base

phosphate group

deoxyribose (sugar)

nitrogen-containingbase

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

The code is found in the

“________” of the ladder.

Each rung is a combination of ________________ bonded together.

The Nitrogen bases are:

C = CYTOSINE

G = GUANINE

T = THYMINE

A = ADENINE

RUNGS

2 nitrogen bases

TA

CG

Nucleotides always pair in the same way.

• The base-pairing rules show how nucleotides always pair up in DNA.

• Because a pyrimidine (single ring) pairs with a purine (double ring), the helix has a uniform width.

“A” bonds ONLY with “___”

“C” bonds ONLY with “___”

This goes on for the entire length of the DNA molecule, which consists of __________ of nitrogen bases.

BILLIONS

CG T

A

C G

CG

CG

CG

TA

TA

TA

TA

T

G

Process Box- Type 1 ReviewBelow are some words/terms that you have recently encountered in the course. Next to each word, write a couple of thoughts that relate to each term.

1. Nucleotides- ______________________________2. 4-_______________________________________3. Billions-__________________________________4. Rung-____________________________________5. Gene-____________________________________

Process Box-Type 1

Think back: What type of organic compounds do nucleotides make up? Are they monomers or polymers?

The ____________________ in DNA will determine what the trait is.

“O W L” meansIf you change the letters to

“L O W”

it no longer means…However…

For example: Lets take a look at the letters of the alphabet…

SEQUENCE OF LETTERS

“A predatory bird”

“A predatory bird”

WON – NOWGOD – DOGANT – TANBAT – TABDNA – DANADD – DADTAR – RATEAR – ARETWO – TOWEAT - ATESAW – WAS

Since DNA consists of billions of nitrogenous base pairings, the amount of variation among organisms is HUGE.

If you change only one letter, the entire code will be changed, and therefore the organism will be different!!

A ladder

twisted

Double helix

Process Box-Type 1It’s all about the numbers.Match the correct number to the correct phrase. 4 30,000 1,000,000,000+

______________ - base pairings______________ - nitrogen bases______________ - genes

•DNA makes up a _______________.

•Chromosomes are found in the nucleus of every cell in the body!!

CHROMOSOME

A gene is a

___________________that codes for a _____________.

There are about __________ genes in an entire DNA molecule

geneSMALL PIECE OF DNA

Specific trait

30,000

Process Box-Type 1

Put the terms below in SIZE order

Gene * Nucleotide * Nitrogen Base * Chromosome

1. What does DNA mean? _____________________________________

2. Suppose one side of a DNA molecule had the bases

A-A-G-T-C- G- A-T-G-G-C-A-C-C. What would the other side of the DNA look like? ____________________________________________

3. What is the function of RNA? _____________________________

4. What is a mutation? ______________________________________

5. What term best describes what a DNA looks like? _________________

6. Explain the relationship between DNA, chromosomes, and genes?

__________________________________________________________

7. If everyone consists of only 4 nitrogen bases (A-T-C-G), why are no two people alike? __________________________________

8. How many chromosomes does a human have? ___________

9. How many genes does a human have? ___________

10. Therefore, approximately how many genes are on a single chromosome? ______

11. If 24% of a DNA molecule is Adenine, what percent would be…

Thymine = ____% Guanine= _____% Cytosine= _____%

If there is 37% of Adenine in a DNA molecule…

How much Thymine? ___________How much Cytosine? ___________How much Guanine? ___________

If there is 23% of Guanine in a DNA molecule…

How much Thymine? ___________How much Cytosine? ___________How much Adenine? ___________

If there is 18% of Cytosine in a DNA molecule, which is the only possibility for another nitrogen base? (Put an ‘X’ on your answer)

________18% Adenine________64% Adenine________ 32% Guanine________ 32% Thymine

UNDERSTANDING THE COMPONENTS OF DNA

Process Box-Type 1You were exposed to a similar graph earlier in the year. Study the graph. Write down a list of at least FOUR things you can recall about the graph. Your statements should be written as complete thoughts.

Replication makes an exact copy of a cell’s DNA • A single strand of DNA serves as a template for a new strand.• The rules of base pairing direct

replication.• DNA is replicated during the

____________stage of thecell cycle.

• Each body cell gets acomplete set ofidentical DNA.

• DNA replication takes place in ___________Nucleus

S (synthesis)

REPLICATION

Proteins carry out the process of replication. • DNA serves only as a template. • Enzymes and other proteins do the actual work of

replication.– Enzymes unzip the _______________– Free-floating nucleotides form hydrogen bonds with the

template strand. nucleotide

The DNA molecule unzips in both directions.

Double helix

BuildDNA

REPLICATION

Process Box-Type 1

What does replication mean?

Why does a cell need to go through replication?

Process Box-Type 1General Word Dissection.Break down these words and define them in your own words. Then write an instance when each one may occur.

What is it? When does it happen?Replication:Transcription:Translation:

RNA carries DNA’s instructions.

• The central dogma states that information flows in one direction from _____________

______________DNA to RNA toprotein

• The central dogma includes three processes.

• RNA is a link between DNA and proteins.

replication

transcription

translation

1) Replication

2) Transcription

3) Translation

RNA differs from DNA in three major ways.

1)RNA has a ____________________

2)RNA has ___________ instead of thymine.

3)RNA is a __________________________.

Ribose sugar

uracil

single-stranded structure

TRANSCRIPTION

The transcription process is similar to replication. • Transcription and replication both involve complex enzymes

and complementary base pairing.

• The two processes have different end results.

– REPLICATION copiesthe ENTIRE________ molecule;TRANSCRIPTION copiesonly part of the DNA molecule-

copies only a specific ___________.– Replication makes

_______ copy; transcription can make ________copies.

growing RNA strands

DNA

onegene

DNA

gene

onemany

TRANSCRIPTION

Process Box-Type 1

What is the Central Dogma of DNA?

Critical Viewing

Similarities between the images:

Differences between these images:

REPLICATION OR TRANSCRIPTION

1.

REPLICATION OR TRANSCRIPTION

2.

REPLICATION OR TRANSCRIPTION

3.

REPLICATION OR TRANSCRIPTION

4.

REPLICATION OR TRANSCRIPTION

5.

Process Box-Type 1

What are two ways to differentiate between replication and transcription?

Amino acids are coded by mRNA base sequences. • Translation converts mRNA messages into polypeptides.• A codon is a sequence of three nucleotides that codes for an

amino acid.

codon formethionine (Met)

codon forleucine (Leu)

TRANSLATION

• For translation to begin, tRNA binds to a start codon and signals the ribosome to assemble.

– A complementary tRNA molecule binds to the exposed codon, bringing its amino acid close to the first amino acid.

TRANSLATION

– The ribosome helps form a polypeptide bond between the amino acids.

– The ribosome pulls the mRNA strand the length of one codon.

TRANSLATION

– The now empty tRNA molecule exits the ribosome.– A complementary tRNA molecule binds to the next

exposed codon.– Once the stop codon is reached, the ribosome

releases the protein and disassembles.

TRANSLATION

Process Box-Type 1

Which one is present first, mRNA or tRNA. Explain.

(Physical trait)

RIBOSOMENUCLEUS

RNA is a “__________” molecule. It helps carry the DNA code to the __________ so it can make the protein.

Skin color/texture

Eye color/shape

Height

Bone density

Hair texture

Etc…

DNA contains the code for what protein will be made by the cell

HELPER

RIBOSOME

•When the sequence of letters is changed. Since the code no longer reads the correct way, the cell does not make the correct protein.

•Consequently, a different trait may appear.

•They are usually _________

Oops!!

bad

Some mutations affect a single gene, while others affect an entire chromosome.

• A mutation is _______________________________.• Many kinds of mutations can occur, especially during

replication.– POINT MUTATIONS– FRAME SHIFT MUTATIONS– CHROMOSOMAL MUTATIONS

• TRANSLOCATION MUTATIONS

A CHANGE IN AN ORGANISM’S DNA

POINT MUTATIONS

• A point mutation substitutes one nucleotide for another.

mutatedbase

• Many kinds of mutations can occur, especially during replication.

– A frameshift mutation inserts or deletes a nucleotide in the DNA sequence.

FRAMESHIFT MUTATIONS

• Chromosomal mutations affect many genes.• Chromosomal mutations may occur during crossing over

– Chromosomal mutations affect many genes.– Gene duplication results from unequal crossing over.

CHROMOSOMAL MUTATIONS

A MUTATION is any _________________ in copying the DNA message.

CHANGE = WRONG ______________

A wrong base in the DNA gives the cell the wrong __________________.

If a cell has the wrong message, the wrong type of ________________ is made.

If the wrong protein is made, the wrong ________________ may appear.

CHANGE

BASE PAIR

MESSAGE

PROTEIN TRAIT

Process Box-Type 1

You recently learned about the different type of mutations that could occur. Now write down AT LEAST TWO different reasons why mutations would/could occur.

Mutations can be caused by several factors.

• Replication errors can cause mutations.

• Mutagens, such as UV ray and chemicals, can cause mutations.

• Some cancer drugs use mutagenic properties to kill cancer cells.

1. Simple copying mistakes during cell reproduction

1. A mutation causes a change in an offspring’s traits only when it takes place in the ___________________ sex cells.

2. Chemicals

1. _______________

2. _______________

3. Radiation

1. _______________

2. _______________

__________________: Any agent that can cause alterations to DNA

PARENTS

NICOTINE

ASBESTOS

SUN

X-RAY

MUTAGEN

HELPFUL MUTATIONSHARMFUL MUTATIONS

Any trait that interferes with the ______________________

and _________________ of an organism.

Any trait that enhances an organisms ability to______________________

and _________________ in its _____________________.

REPRODUCTION

SURVIVAL

REPRODUCE

SURVIVE ENVIRONMENT

1. The term “clone” refers to organisms having ____________________

Two “clones” are exact _______________ of each other.

Same _______ = Same __________ = Same _________

2. Examples of clones:

a. _________________: form from the splitting of _____ fertilized egg

b. Clone organisms produced in ___________________

IDENTICAL DNA

copies

DNA GENES TRAITS

IDENTICAL TWINS ONE

LABORATORY

Fraternal Twins vs Identical Twins_____________________ eggs are fertilized by_____________________ sperm.

Each egg and sperm carry __________________combinations of ____________.

Therefore, each offspring will ________________genetically.

TWO DIFFERENT

TWO DIFFERENT

DIFFERENTDNA

VARY

10

20

20

20

20

20

10

RemoveUnfertilized

Ovum

Destroy Nucleus

RemoveBody Cells

Insert Nucleus from Dark frog into egg

of Light frog

DNA MOLECULE

_______________(SHAPE)

SIDE PARTS RUNG PARTS

___________ ___________

___________

& ___________

___________ ___________

What is the difference between a cell, nucleus, chromosome, genes, and DNA?

How are they related?

WHAT IS THE DIFFERENCE BETWEEN…

Cell: ________________________________

Nucleus: ________________________________

Chromosome: _________________________________

Gene(s): _____________________________________

DNA: ________________________________________

How are they related? ____________________________________________________________________________

TYPE II’SIf you were to observe your DNA molecule and compare it to another person’s DNA, what is one thing that you’d expect to find in common?What is one thing you’d expect to be different?

Process Box-Type 2

Explain what all DNA has in common and then describe how DNA differs. Give examples of both.

Process Box-Type 2Describe the components of a nucleotide using these terms: nitrogenous base, deoxyribose sugar, phosphate, double helix, sides, rungs.

Process Box-Type 2

Differentiate between a nitrogen base and a nucleotide.

1. What does DNA mean? _____________________________________

2. Suppose one side of a DNA molecule had the bases

A-A-G-T-C- G- A-T-G-G-C-A-C-C. What would the other side of the DNA look like? ____________________________________________

3. What is the function of RNA? _____________________________

4. What is a mutation? ______________________________________

5. What term best describes what a DNA looks like? _________________

6. Explain the relationship between DNA, chromosomes, and genes?

__________________________________________________________

7. If everyone consists of only 4 nitrogen bases (A-T-C-G), why are no two people alike? __________________________________

8. How many chromosomes does a human have? ___________

9. How many genes does a human have? ___________

10. Therefore, approximately how many genes are on a single chromosome? ______

11. If 24% of a DNA molecule is Adenine, what percent would be…

Thymine = ____% Guanine= _____% Cytosine= _____%

Deoxyribo-nucleic acid

T- T- C- A- G-C--T- A- C- C- G-T- G-Gcarry the DNA code to the ribosome

A random change in the DNA code

Double helix

A chromosomes is made up of DNA, which is consists of about 30,000 genes

bc it’s the sequence of nitogen bases that makes us different46

About 30,000

~ 650

24 26 26

Process Box-Type 2

Describe the difference between replication and transcription.

Process Box-Type 2

Describe where AND when replication occurs versus where AND when transcription occurs.

Process Box-Type 2

What is the role of tRNA during translation? Include the words codon, amino acids, proteins, mRNA, and ribsome in your response.