DNA Replication and Protein Synthesis

amino acids

building blocks of proteins

DNA

deoxyribonucleic acid, a self-replicating material present in nearly all living organisms. Double-stranded nucleic acid that carries genetic information.

RNA

A single-stranded nucleic acid that passes along genetic messages

Nucleotide

A building block of DNA, consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group.

Nucleotide structure

-deoxyribose sugar

-nitrogenous base

-phosphate group

DNA macromolecule

nucleic acid

DNA monomers are called

nucleotides

DNA sugar

deoxyribose

RNA sugar

ribose

Nobel Prize Winners for DNA structure

James Watson and Francis Crick

DNA structure and shape

double helix (twisted ladder)

Polypeptide

chain of amino acids

Rosalind Franklin

Woman who generated the famous Photo 51 x-ray image of DNA, she povided Watson and Crick with key data about DNA (was not credited until after her death and did not receive the Noble Prize)

protein synthesis

The creation of a protein from a DNA template.

Nitrogen bases in DNA

Adenine, Thymine, Guanine, Cytosine

A->T

C->G

Nitrogen bases in RNA

Adenine, Uracil, Cytosine, Guanine

A->U

C->G

Where are the nitrogen bases found on DNA & how are they bonded?

inside or middle of the double helix; bonded by hydrogen bonds

Where are the sugars and phosphates found on DNA?

they make up the side of the double helix

DNA helicase

An enzyme that unwinds and separates the DNA double helix during DNA replication

semiconservative replication

each new DNA molecule consists of one new strand and one old strand

DNA polymerase

produces the new DNA strand

Overall process of protein synthesis

DNA > RNA > polypeptide (protein)

RNA polymerase

the enzyme responsible for creating RNA from a DNA template

mRNA (messenger RNA)

a single-stranded RNA molecule that encodes the information to make a protein

Codon

three-nucleotide sequence on messenger RNA that codes for a single amino acid

Anticodon

group of three bases on a tRNA molecule that are complementary to an mRNA codon

"start" codon

AUG (methionine)

"Stop" codon

UAA, UAG, UGA

Transcription

synthesis of an RNA molecule from a DNA template

DNA > RNA

Translation

Process by which mRNA is decoded and a protein is produced

RNA > Protein

genetic code is non-ambiguous

each codon specifies one amino acid

genetic code is redundant

more than one codon may for a particular amino acid

Mutation

a change in nucleotide sequence of DNA. A change in a gene or chromosome.

substitution mutation

Mutation in which a single base is replaced, potentially altering the gene product.

insertion mutation

the addition of one or more nucleotide base pairs into a DNA sequence

deletion mutation

a mutation in which one or more pairs of nucleotides are removed from a gene

silent mutation

alters a base but does not change the amino acid

missense mutation

a nucleotide-pair substitution that results in a codon that codes for a different amino acid

nonsense mutation

changes a normal codon into a stop codon; most damaging mutation

frameshift mutation

mutation that involves the insertion or deletion of a nucleotide in the DNA sequence

Mutagen

A chemical or physical agent that interacts with DNA and causes a mutation.

number of amino acids

20 amino acids

tRNA (transfer RNA)

transfer RNA; type of RNA that carries amino acids to the ribosome; contains the anticodon

Central Dogma

theory that states information in cells only flows from DNA to RNA to proteins

DNA > RNA > Protein

Fred Griffith (1928)

found a "transforming principle" (DNA) that changed a harmless bacteria (R Bacteria) into deadly bacteria (S Bacteria), but didn't know what it was

Avery, MacLeod, McCarty

Determined that DNA was Griffith's "Transforming Factor" using mice in their experiment

Chargaff's Rule

the number of Adenine will equal the number of Thymine and the number of Cytosine will equal the number of Guanine