DNA to PROTEINCHAPTER 12

DEOXYRIBONUCLEIC ACID

DNA: replication and protein synthesis

Where have we seen DNA being replicated?

MITOSIS AND MEIOSIS

Building blocks of DNA: Nucleotides

The sugar

The phosphate The phosphate

Deoxyribose

The nitrogenous bases

The Purines

Why are these called nitrogenous bases?

The nitrogenous bases

The Pyrimidines

How are the pyrimidines different from the purines?

Four different Nucleotides

BASIC STRUCTURE

DNA is a polymer formed by base pairing: Base pairing rule

The Double Helix

A.The overall shape of DNA is described as a double helix (a twisted ladder).

B.What force holds the two strands together?

How are DNA and RNA similar?

DNA is composed of nucleotides and RNA is composed of nucleotides

How are DNA and RNA different?

How are DNA and RNA different?

DNA… Nucleotides = deoxyribose sugar Double helix structure Stays inside nucleus

RNA… Nuleotides = ribose sugar Single-strand structure Located both inside and outside of nucleus Uracil instead of thymine

DNA Replication

Set up your DNA by applying the base pair rules

Strand 1 Complementary Strand 2ATCGG

Enzymes involved in DNA replication

Helicase – opens the double helix to allow for replication

DNA polymerase – reads the original DNA strand and lays down complementary bases

Ligase – glues the newly formed DNA together

DNA replication practice

You are DNA polymerase. Helicase has opened the DNA strand – read each side and produce the complementary copies.

__________________________________A G G T A A C C G G T T A C G A T T A TT C C A T T G G C C A A T G C T A A T A

A G G T A A C C G G T T A C G A T T A TT C C A T T G G C C A A T G C T A A T A

PARTNER PRACTICE

Person one uses their nucleotides as free nucleotides

Person two works with partner to replicate their original strand

Discuss the enzymes as you model the process

Do # 9 IN YOUR NOTES TO PRACTICE BASE PAIRING RULES AGAIN__________________________________

A G T C C G T T A G T

T C A G G C A A T C A

Hydrogen bonds

Nucleotide

Sugar-phosphate backbone

Key

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Figure 12–7 Structure of DNASection 12-1

Use your text to complete the diagram and provide written details for the process shown

Homework

Complete labeling of notes cover Complete DNA replication labeling and details Complete Section 10-1 Review – accuracy!

Protein Synthesis= transcription and translation DNA contains all the information for your

traits – the genes These genes are blueprints and need to

remain safe – kept inside the nucleus Copies can be made though – a messenger

Genotype Phenotype

DNA mRNA tRNA PROTEIN

Transcription Translation

(DNA to mRNA) (mRNA – tRNA to protein)

from to to make up

Concept MapSection 12-3

also called which functions to also called also called which functions towhich functions to

can be

RNA

Messenger RNA Ribosomal RNA Transfer RNA

mRNA Carry instructions rRNACombine

with proteins tRNABring

amino acids toribosome

DNA Ribosome Ribosomes

Transcription

#8 RNA polymerase reads one of the DNA strands and makes a complementary mRNA

#10 transcription details Occurs in the nucleus The gene sequence on DNA gets transcribed Promoter region on DNA marks where

transcription should start and terminator region marks where it should stop

mRNA

RNA polymerase – key enzyme mRNA is a “copy” of the gene sequence and

can leave the nucleus mRNA finds its way to a ribosme and the next

step in making a protein can occur - TRANSLATION

CLICK ON PICTURE FOR ANIMATION ON TRANSCRIPTION

mRNA

No T (thymine) so when it reads the nucleotide A on DNA it matches it with ____?

Do #11 in notes

#12 – TRANSLATION and tRNA

Once mRNA is made it attaches to a ribosome

tRNA = transfer RNA and they carry amino acids

Amino acids are the building blocks of proteins (remember?)

Translation

Ribosomes are the site of protein synthesis Click here to see mRNA and tRNA work

together at that ribosome to build a protein

Codon = mRNAAnti-codon = tRNA

Copy down this DNA sequence

This is the template strand of DNA, complete the complementary strand sequence below the template.

TRANSCRIPTION: read the template DNA strand and write the complementary mRNA

TRANSLATION: based on your mRNA, determine the proper amino acid sequence

CAG GTG AAT TGG GGC CTC CAC TTT

Copy this DNA sequence down

CAG GTG AAT TGG GGC CAC CAC TTT

REPEAT ALL THE STEPS AND DETERMINE THE AMINO ACID SEQUENCE FOR THIS GENE!

COMPARE: what is the mistake?

CAG GTG AAT TGG GGC CTC CAC TTT

CAG GTG AAT TGG GGC CAC CAC TTT

One incorrect amino acid

GENOTYPE to PHENOTYPE

Deletion

Duplication

Inversion

Translocation

Figure 12–20 Chromosomal Mutations

Section 12-4

Let’s Review

DNA Structure is a _____ ______ DNA is composed of __________

What are four that make up DNA? A T C G

Purines Pyrimidines

Adenine Guanine Cytosine Thymine

Phosphate group Deoxyribose

Figure 12–5 DNA NucleotidesSection 12-1

Hydrogen bonds

Nucleotide

Sugar-phosphate backbone

Key

Adenine (A)

Thymine (T)

Cytosine (C)

Guanine (G)

Figure 12–7 Structure of DNASection 12-1

Use your text to complete the diagram and provide written details for the process shown

from to to make up

Concept MapSection 12-3

also called which functions to also called also called which functions towhich functions to

can be

RNA

Messenger RNA Ribosomal RNA Transfer RNA

mRNA Carry instructions rRNACombine

with proteins tRNABring

amino acids toribosome

DNA Ribosome Ribosomes

RNADNA

RNApolymerase

Figure 12–14 TranscriptionSection 12-3

Adenine (DNA and RNA)Cystosine (DNA and RNA)Guanine(DNA and RNA)Thymine (DNA only)Uracil (RNA only)