DNA & RNAUnit 7

Chapter 12

DNADeoxyribonucleic

Acid

RNARibonucleic

Acid

Where does DNA “live”?

The NUCLEUS!

Why is DNA so Important?* DNA is a nucleic acid that contains the

genetic information used in the development and functioning of all living things and some viruses.

* DNA is like blueprints, instructions, or a code for making proteins

* DNA’s codes are converted/changed into messages (mRNA) for ribosomes to read and then make proteins.

* Proteins do most of the hard work of keeping us alive

What are the parts of DNA?

*

D = Deoxyribose (SUGAR)

P = Phosphate

The “Backbone”

Has 2 Parts

2 Strands called:

Double Helix

What are the parts of DNA?

* The

“Rungs”

The Nitrogen Bases

A = Adenine

T = Thymine

C = Cytosine

G = Guanine

A - T

C - G

How to remember Nitrogen Bonds:

A bonds with TThink: A T & T

phone company

How to remember Nitrogen Bonds:

C bonds with GThink: Half circles

These are 2 examples of nucleic acids:

A. Chloroplasts & Mitochondria

B. Carbohydrates & LipidsC. DNA & RNAD. Nucleus & Ribosomes

Clicker Question #1

DNA holds the instructions for making:

A. EnergyB. ProteinsC. Carbon dioxideD. Deoxyribose

Clicker Question #2

If 20% of a DNA’s strand contains Thymine, then:

A. it also has 80% Guanine

B. it also has 50% Cytosine

C. it also has 80% Adenine

D. it also has 20% Adenine

Clicker Question #3

What type of sugar is found in DNA?

A. PhosphorousB. ThymineC. RiboseD. Deoxyribose

Clicker Question #4

The DNA’s code is converted into _____ so it can be sent to ribosomes

to make the proteins.

A. DNAB. mRNAC. tRNAD. ATP

Clicker Question #5

What are the parts of DNA?

*

Nucleotides:

1 Sugar

1 Phosphate

1 Nitrogen Base

Lets Practice:What are the complementary nitrogen

bases in this sequence of DNA?

ATT CGT TAT CGT CTG AAA ACG

TAA GCA ATA GCA GAC TTT TGC

What did we just do?

Yes!We made

DNA!

Why is mRNA Important?

* mRNA is created by DNA in the nucleus

* mRNA contains the messages from the DNA and are sent to ribosomes for them to read the instructions for making proteins

* DNA is too big and CAN’T leave the nucleus…it must send messages

What are the parts of RNA?

* Just Like DNA, RNA has:

Sugar

Phosphate

Nitrogen BaseBUT…..

RNA is Made of:

Ribose (SUGAR)

Phosphate (same as DNA)

Nitrogen Bases (A,U, C, G)

First:

Notice that RNA has 1 Strand!NO THYMINE in

RNA!!U stands for Uracil….

a different nitrogen base

RNA Nitrogen Bases:

A bonds with U

C bonds with G

THYMINE in RNA!!

What 3 things make up a nucleotide?

A. Nucleus, DNA, & RNAB. Adenine, Thymine, & CytosineC. Sugar, Phosphate, & a

Nitrogen baseD. Chromosomes, Genes, & DNA

Clicker Question #6

Where is mRNA made?

A. In the nucleusB. In the cytoplasmC. In the mitochondria

D. In the ribosomes

Clicker Question #7

What type of sugar does RNA have?

A. DeoxyriboseB. CarbohydrateC. Ribonucleic acidD. Ribose

Clicker Question #8

Which of the following nitrogen bases does RNA not

have?

A. UracilB. ThymineC. AdenineD. Cytosine

Clicker Question #9

If a strand of DNA contains 40% of Cytosine, then

A. it also contains 40% Guanine

B. it also contains 60% Thymine

C. it also contains 40% Cytosine

D. it also contains 60% Guanine

Clicker Question #10

How does DNA tell the cell to make a specific kind of protein?

* First: Transcription * Second: Translation

* There are 2 major steps in this process

How does DNA tell the cell to make a specific kind of protein?

Transcription : Process in which mRNA is synthesized from the DNA template.

* mRNA: (messenger RNA) holds the

recipe for making proteins

*** Transcription is when mRNA is made from DNA.***

HINT:

How does Transcription work?

* QUESTION…have you been to court?

* There is a person typing what is said and is creating a “court transcript”…which is really a code…shortened version…and later the transcript is translated into all the words that were said for a record.

SHORTENED CODE = mRNA

Transcription Video….

Lets Practice:Create a RNA strand using this

sequence of DNA?

ATT CGT TAT CGT CTG AAA ACG

UAA GCA AUA GCA GAC UUU UGC

We just transcribed DNA into mRNA!

This is mRNA!

What does mRNA do?A. It carries the instructions from

DNA to ribosomes to make proteins

B. It carries instructions from the ribosomes to the nucleus to make DNA

C. It carries the instructions from the nucleus to the mitochondria to make energy

D. It carries instructions from the nucleus to the cytoplasm to make energy

Clicker Question #11

What is transcription?

A. The process of making energy

B. The process of making proteins

C. The process of making DNA

D. The process of making mRNA

Clicker Question #12

Lets Practice This Again:Create a RNA strand using this

sequence of DNA?

ACA CGA TTA CGG ATA CGC ATC

UGU GCU AAU GCC UAU GCG UAG

What did we just

do?

YES! We transcribed/made

mRNA from DNA

Now what

?

Now What?...Translation!

Translation: Process in which mRNA attaches to the ribosome and a protein is assembled/made.

* Codon: 3 base code in DNA or RNA

Words to know:

* Amino Acid: Compounds joined by peptide bonds

to build proteins* Ribosome: “Reads” mRNA recipes so it can

synthesize/make proteins

ACG ATA CGG CTTThere are 20 different Amino Acids.

Different combination of Amino Acids make different kinds of proteins.

Now What?...Translation!

* tRNA: (transfer RNA) Type of RNA that

transports amino acids to the ribosome

More Words to know:

* Anticodon: Nitrogen bases that can pair that

corresponds with the codons on the mRNA

tRNAAmino Acid

Anticodon

What happens during translation?

Ribosome

Peptide chain/

Protein Chain tRNA

Amino Acid

Anticodon

Codon

Translation Video...

Link to Transcription Animation

Click Here

Where does translation occur?

A. In the nucleusB. In the mitochondriaC. In the DNAD. In the ribosome

Clicker Question #13

What is made during translation?

A. DNAB. mRNAC. ProteinD. Energy

Clicker Question #14

What is another name for polypeptide chain?

A. Protein chainB. Carbohydrate chain

C. Lipid chainD. Nucleic acid

Clicker Question #15

#1. AUG GCA UCC UGA

Methionine, Alanine, Serine, Stop

#2. AUG CCC GGU UAG

Methionine, Proline, Glycine, Stop

#3. AUG AAG GUG UGAMethionine, Lysine, Valine, Stop

Translating mRNA codes into amino acids to create polypeptid chains

(protein chains)

What is the amino acid for the following codons?

AAUAsparagine

(Asn)

GUGValine

(Val)

UGGTryptophan

(Trp)

How can knowing amino acid sequences in organisms help

biologists?We can use the sequences to see how organisms

are related!

Fish Sequence: Methionine, Isoleucine, Arginine, Isoleucine, Glycine, Serine

Frog Sequence: Methionine, Isoleucine, Serine, Leuicine, Lysine, Lysine

Bird Sequence: Methionine, Isoleucine, Serine, Glycine, Alanine, Valine

Lizard Sequence: Methionine, Isoleucine, Serine, Glycine, Alanine, Tyrosine

Which of the following two organisms are MOST closely related?

The end…For now…

DNA Mutations & Technology

What are genetic mutations?

Mutation: Permanent change in a cell’s DNA, ranging from changes in a single base pair to deletions of large sections of chromosomes.

Causes of mutations include:* Viruses

* Radiation

* Chemicals

* Errors during mitosis and meiosis

Are mutations harmful?

Some mutations are harmful, some are beneficial, and some do nothing.

Harmful example:

- Some mutations cause cancer & genetic disorders

Are mutations harmful?

Helpful example:

- Sickle cell anemia prevents malaria

Are mutations harmful?

Not harmful or helpful:

- Peppered moths come in dark or light colors

What are some types of mutations?

There are many different types:

Chromosomal mutations

1. Insertion

What are some types of mutations?

2. Deletion

What are some types of mutations?

3. Translocation

What are some types of mutations?

4. Duplication

What are some types of mutations?Gene mutations

Point mutations involve changes in one or a few nucleotides1. Substitutions: one base is

changed to a different base. Only affects one amino acid or has no effect at all.

What are some types of mutations?Gene mutations

Point mutations involve changes in one or a few nucleotides2. Insertions and deletions: one base is inserted or removed from the DNA sequence. These are called frameshift mutations because they shift the “reading frame” of the genetic message.

How has technology changed DNA?

Genetic Engineering: Technology used to manipulate an organism’s DNA by inserting the DNA of another organism.

Transgenic Organism: Organism that is genetically engineered by inserting a gene from another organism.

How has technology changed DNA?

Gel Electrophoresis: Process that involves using electric current to separate certain biological molecules by size.

We use this to see DNA fragments to create a DNA fingerprint

- DNA fingerprints have 2 major uses:

1.Solve crimes

2.Figuring out “who’s the baby’s daddy”

DNA Fingerprinting

Which of the following are his/her parents?

Who did it?

What is the human genome?Genome: Total DNA in each cell nucleus of an

organism

The Human Genome Project:* Began in 1990 and completed in 2003* Found that we have 3 BILLION chemical base

pairs* Used to understand genetic disorders

What is cloning?

Cloning: Process in which large numbers of identical recombinant DNA molecules are produced.

“Dolly” the sheep was the first cloned animal