Protein Synthesis: DNA CONTAINS THE GENETIC INFORMATION TO PRODUCE PROTEINS BUT MUST FIRST BE CONVERTED TO RND TO DO SO.

Why do cells need DNA? DNA contains the information cells need to function and live.

Why do cells need to replicate (copy) their DNA? To make new cells

How do cells replicate their DNA? unwound by an enzyme. 1. The DNA double helix is

adds complementary nucleotides. 2. Another enzyme moves down the 2 original DNA strands and

3. Two separate DNA molecules are formed, each with one new strand and one old strand.

Replication Mistakes 6 billion base pairs per cell. All are replicated in a few hours. Mistake happens one per billion nucleotides.

Mistakes = Mutations Mutations are changes in the base sequence of the DNA molecules. This can have serious affects on genes and the functions of cells. Cancer is caused by mutations in DNA.

Mutagens Physical of chemical factor that increases the frequency of mutations. Examples: UV rays, X-rays, smoking

3 Types of Mutations Insertion: Adding nucleotide Deletion Deleting nucleotide Substitution Switch nucleotide

Protein Synthesis Transcription

DNA vs. RNA Single stranded Ribose sugar Uracil Anywhere Double stranded Deoxyribose sugar Thymine Nucleus

3 Types of RNA Messenger RNA (mRNA): Carries information from DNA to ribosome for________________. Transfer RNA (tRNA): Transport _________________. Ribosomal RNA (rRNA): makes up the _____________. protein synthesis amino acids ribosomes

TRANSCRIPTION PROCESS OF MAKING RNA FROM DNA

Steps of Transcription 1. An _________ attaches to a section of DNA, separating the two strands. 2. The enzyme moves down the DNA, building a strand of RNA that is ______________ to the DNA. 3. The enzyme reads a _____ code and the new strand of RNA is completed and moves into the _______________. enzyme complementary STOP cytoplasm

Protein Synthesis Translation  process of making proteins from RNA

The genetic code The base sequence is read in groups of _____ ___________ __________. Each 3-nucleotide sequence is called a ______. Each codon encodes for a specific ______ _____or a ______or ______signal. three adjacent nucleotides codon amino acid startstop

Amino Acid Anti-codon

Steps of Translation 1. mRNA attaches to a _________. Amino acids floating in the cytoplasm are transported to the ribosome by _______. 2. The first tRNA binds to the ______ codon: AUG. ribosome tRNA start

3. Another tRNA binds to the next codon and carries the appropriate amino acid. A _______ ______ forms between the two amino acids. 4. The first tRNA leaves and the ribsome moves across the next _______. peptide bond codon

5. Another tRNA binds to the codon and attaches the corresponding amino acid. The ____________ chain continues to grow. 6. Finally, the ribosome reads the ______ ______, and the polypeptide falls off the ribosome. polypeptide STOP codon

Amino acid tRNA ribosome mRNA polypeptide

The final step of protein synthesis: The polypeptide made at the end of translation, folds into the proper ________, becoming a functional ________. shape protein

The central dogma of biology DNA  RNA  protein