Dna Replication, Translation, And Transcription

7/28/2019 Dna Replication, Translation, And Transcription

1/43

Replication

TranscriptionTranslation


2/43

DNA

1. Double Stranded Helix

2. Hydrogen Bonds betweenNitrogenous Base Pairs

3. Adenine-Thymine and

Guanine-Cytosine


3/43


4/43

Gene

A gene is a segment of DNA

A gene is a sequence of nucleotides that

codes for a functional product (usually a

protein)

1 gene = 1000s of base pairs

41000 possibilities of combinations


5/43

A Gene is a Segment of DNA

When a gene is expressed, DNA is transcribed to produce

RNA and RNA is then translated to produce proteins.


6/43

Genotype and Phenotype

Genotype

1. Genetic Composition of an Organism

2. Represents the Potential Properties

Phenotype1. The Expression of the Genes

2. What You See


7/43

Replication

The duplication of DNA which occursduring the S phase of Interphase.

1 Strand 2 Complementary Strands

DNA Polymerase


8/43


9/43


10/43

One More Time!


11/43

thymine

adenine

cytosine

guanine

phosphate

deoxyribose sugar

DNA nucleotide

Deoxyribose sugar

phosphate

Nitrogenous base

(guanine)

RNA nucleotide

ribose sugar

phosphate

Nitrogenous base

(uracil)

Sugar / phosphate strand

Nitrogenous base rung

Hydrogen bond

(H-bonds)


12/43

Step 1: Hydrogen bonds

between complimentary

bases break

DNA unzips


13/43

Step 2: DNA strands

pull apart from each other


14/43

Step 3: DNA nucleotides in the cell

match up with each side of theunzipped DNA

each unzipped strands forms a

template for a new strand


15/43

Step 4: Each old strandforms a template for a

new strand

two identical DNAmolecules form

old (original) strand

new strand, identical

sequence to the original


16/43

Transcription

The process by which a molecule of DNA iscopied into a complementary strand of

RNA.

1 Strand DNA

2 Strands RNA RNA Polymerase


17/43

DNA RNA


18/43


19/43


20/43


21/43

Label the Following


22/43

One More Time!


23/43

Step 1: Hydrogen bonds

between complimentary

bases break

DNA unzips


24/43

Step 2: DNA strands

pull apart from each other


25/43

Step 3:

RNA nucleotides

in the cell match

up with only one

side of the

unzipped DNA

each unzipped

strands forms atemplate for a

mRNA strand

RNA nucleotide


26/43

Step 4:

RNA nucleotides

continue to match

up withunzipped DNA

until the message

is completely

transcribed

mRNA strand

One side of DNA strand


27/43

Step 4:

mRNA strand

breaks offfrom the DNA

strand

mRNA strand

One side of DNA strand


28/43

Step 5:

mRNA strand

leaves the

nucleus for

the ribosome


29/43

Step 6: Once the mRNA

leaves, the DNA zips

back together


30/43

Translation

The process in which the information in thenucleotide base sequence of mRNA is used to

dictate the amino acid sequence of a protein.

1 Strand RNA Amino Acid Chain Protein


31/43


32/43

The problem: How does a

particular sequence of

nucleotides specify a particular

sequence ofamino acids?

By means oftransfer RNA

molecules, each specific for one

amino acid and for a particular

triplet of nucleotides in mRNA

called a codon. The family of

tRNA molecules enables the

codons in a mRNA molecule to

be translated into the sequenceof amino acids in the protein.
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/Nucleotides.htmlhttp://users.rcn.com/jkimball.ma.ultranet/BiologyPages/N/Nucleotides.html


33/43

RNA and Protein Synthesis

RNA is a Single

Stranded Nucleic Acid

RNA Acts as aMessenger between

DNA and Ribosomes

Process Takes Amino

Acids and FormsProteins


34/43

Why Is It Necessary?

DNA / Nucleus

Ribosomes / Cytoplasm

Need a Messenger


35/43

Definitions

Codon

1. Three-base segment of mRNA that

specify amino acids.

2. Sense Codons3. Nonsense Codons

Anticodon

1. Three-base segment of tRNA that

dock with a codon.

2. Docking results in deposition of amino acid.


36/43

Protein Synthesis

Proteins are coded directly from the mRNA

with 3 bases (one codon) for each amino

acid. Whats up with that?


37/43


38/43

Mutation

A change in the nitrogenous base sequence

of DNA; that change causes a change in the

product coded for by the mutated gene.


39/43

MutationsWhat happens when you get insertions or deletions of bases in

the DNA sequence?

Usually you end up with a mess.

THE BIG FAT CAT ATE THE RAT AND GOT ILL

Deletion of one base

THE IGF ATC ATA TET HER ATA NDG OTI LL

And its all pops and buzzes.


40/43

Sickle-CellAnemia


41/43

Definitions

CarcinogensSubstances and preparations which, if they areinhaled or ingested or if they penetrate the skin;may induce cancer or increase its incidence and

can affect any cells or tissues Mutagens

may induce hereditary genetic defects or increasetheir incidence and effect the germ cells (gonads)

Teratogens

may induce non-hereditary congenitalmalformations or increase their incidence andeffect the growing fetus


42/43

Mutagens

Tobacco products

Nitrous Acid

Mold Toxins X-rays

Gamma Rays

UV Radiation Some Artificial Sweeteners


43/43

Dna Replication, Translation, And Transcription

Documents

Transcript of Dna Replication, Translation, And Transcription