dna => rna => protein
DESCRIPTION
DNA => RNA => Protein. Central Dogma of Life. DNA. Name: D eoxyribo n ucleic A cid “ Molecule of Life ” Stays in the nucleus of eukaryotes Codes for RNA and ultimately proteins Structure: Double stranded (double helix) Monomers : Nucleotides Adenine, Guanine, Cytosine, & Thymine. RNA. - PowerPoint PPT PresentationTRANSCRIPT
DNA => RNA => ProteinCentral Dogma of Life
DNA• Name: Deoxyribonucleic Acid
• “Molecule of Life”• Stays in the nucleus of
eukaryotes• Codes for RNA and ultimately
proteins
• Structure: Double stranded (double helix)
• Monomers: Nucleotides• Adenine, Guanine,
Cytosine, & Thymine
RNA• Name: Ribonucleic Acid• Disposable copy of DNA- moves to the cytoplasm to make proteins
• Structure: Single Stranded
• Monomer: Nucleotides• Adenine, Guanine,
Cytosine, & Uracil• Three kinds
• mRNA - messenger• tRNA - transfer• rRNA - ribosomes
Nucleotide• Remember that a nucleotide is made up of three parts:
1. Phosphate group
2. 5 carbon sugar
3. Nitrogenous base • The nitrogenous base differs
• A, T, C or G in DNA• A, U, C or G in RNA
DNA Replication• DNA must be replicated
• When does this happen during the cell cycle?
• When does DNA get replicated?• When new cells need to be made
• To replace dead or damaged cells• To grow and develop• To form a new life- fertilization birth
• 2 strands of DNA run in opposite directions
DNA Replication• Enzymes involved
• DNA helicase- unwinds, unzips double stranded DNA, exposes nitrogenous bases so they can be based paired
• DNA polymerase- adds new DNA nucleotides
• DNA replication is semi-conservative, meaning that each new DNA strand is made of one old and one new strand
Protein
• Monomers: Amino Acids
• Functions: • Enzymes• Structural Proteins
• In the cell membrane• Give characteristics to cells
• They make you, YOU!
Genes
• Segments of DNA • The code on the DNA codes for a PROTEIN.
How to get from DNA to Proteins
• Transcription - The rewritten language of DNA nucleotides to RNA nucleotides
• Translation - The translation from the language of nucleotides to the language of amino acids.
Transcription: From DNA => mRNA• Rewriting the nucleotide
code• In the Nucleus• The DNA transcribed is
for a certain protein (from a gene)• DNA splits• 1 Strand is used as a
template• RNA polymerase is used
to build mRNA strand.• Once complete the mRNA
goes into the cytoplasm.
Codons
• Series of 3 nucleotides on the mRNA
• Each codon codes from only on specific Amino Acid
1 codon for 1 amino acid
Translation From mRNA => Proteins
• mRNA comes from the nucleus to the Ribosome
• At the Ribosome, the code of mRNA nucleotides is translated into the language of Protein amino acids using tRNA
tRNA• RNA molecules that
helps build proteins• One end has an amino
acid attached• One end has an
anitcodon• Series of 3 nucleotides on
the tRNA• Match with the mRNA
codons• The amino acid is
specific to the anticodon
Translation1. mRNA enters the ribosome
• Always starts with AUG on mRNA
2. tRNA from the cytoplasm attaches to the mRNA
3. Amino acid attached to tRNA is dropped off
4. The next tRNA with the matching anitcodon to the next codon enters the ribosome
5. The amino acid is dropped off and tied to the 1st amino acid…Until Stop Codon.
Amino AcidRibosome
tRNA
What is the Protein?
• The series of Amino Acids created in translation
• The order of amino acids determine the protein
• Change the amino acids, you change the protein
Transcription and Translation Ex.
• DNA Sequence• TACATACGCTTT
• Complementary RNA• AUGUAUGCGAAA
• Amino Acid Sequence• Met-Try-Ala-Lys
Transcription and Translation Ex.
• DNA Sequence• TACATACGCTTT
• Complementary RNA• AUG/UAU/GCG/AAA
• Amino Acid Sequence• Met-Try-Ala-Lys
Mutations
• Occur when DNA is replicated during the cell cycle• substitutions• deletions• insertions
Base Substitution
• One DNA nucleotide is changed• May or may not cause
a change in the protein• No change = silent
mutation• Could change amino
acid, and therefore the function of the protein
Silent Mutation
• Original DNA Sequence• TACATACGCTTT
• Complementary RNA• AUGUAUGCGAAA
• Amino Acid Sequence• Met-Try-Ala-Lys
• Mutated DNA Sequence• TACATGCGCTTT
• Complementary RNA• AUGUACGCGAAA
• Amino Acid Sequence• Met-Try-Ala-Lys
Silent Mutation
• Original DNA Sequence• TACATACGCTTT
• Complementary RNA• AUG/UAU/GCG/AAA
• Amino Acid Sequence• Met-Try-Ala-Lys
• Mutated DNA Sequence• TACATGCGCTTT
• Complementary RNA• AUG/UAC/GCG/AAA
• Amino Acid Sequence• Met-Try-Ala-Lys
Mutation: Change in Protein
• Original DNA Sequence• TACATACGCTTT
• Complementary RNA• AUGUAUGCGAAA
• Amino Acid Sequence• Met-Try-Ala-Lys
• Mutated DNA Sequence• TACACACGCTTT
• Complementary RNA• AUGUGUGCGAAA
• Amino Acid Sequence• Met-Cys-Ala-Lys
Mutation: Change in Protein
• Original DNA Sequence• TACATACGCTTT
• Complementary RNA• AUG/UAU/GCG/AAA
• Amino Acid Sequence• Met-Try-Ala-Lys
• Mutated DNA Sequence• TACACACGCTTT
• Complementary RNA• AUG/UGU/GCG/AAA
• Amino Acid Sequence• Met-Cys-Ala-Lys
Base Insertion & Deletion
• Adding or taking away of nucleotides
• Will change the overall order of the amino acids, and therefore the Protein will change
Mutation: Change in Protein
• Original DNA Sequence• TACATACGCTTT
• Complementary RNA• AUG/UAU/GCG/AAA
• Amino Acid Sequence• Met-Try-Ala-Lys
• Mutated DNA Sequence• TACAGTACGCTTT
• Complementary RNA• AUG/UCA/UGC/GAA/A
• Amino Acid Sequence• Met-Ser-Cys-Glu
Mutagens
• What causes mutation• UV light• X-rays• Chemicals
DNA => Protein