Protein Synthesis

I. What is Protein Synthesis? Using RNA to make a protein from the DNA instructions The monomers of protein are Amino Acids

II. DNA and RNA II. DNA and RNA are Nucleic Acids. What’s the difference between DNA and RNA?

DNA: Deoxyribose Sugar Nitrogen Bases: G, C, A, T Double Stranded Shape Instruction Manual- holds Instructions

RNA Ribose Sugar Nitrogen Bases: Single Stranded G, C, A, U (uracil U pairs with A Single Stranded Worker- uses instructions to make proteins

iii. Why is making proteins important? Proteins help with: Movement: Muscles and bones are made of proteins Regulation: Enzymes control reactions Structure- all living things are built from proteins

4. Transports- Hemoglobin 5. Defense- Antibodies

IV. How does Protein Synthesis work? Transcription Occurs in the Nucleus mRNA makes a copy of DNA instructions Matching Bases: U : A G : C

Matching bases of DNA & RNA Double Stranded DNA Unzips

Matching bases of RNA to DNA

U (instead of T) matches with A

U (instead of T) matches with A

RNA Splicing/Processing Occurs in the Cytoplasm Pieces of the pre-mRNA are removed to create mRNA

RNA Splicing/Processing Using the pre-mRNA strand, remove the underlined part of the pre-mRNA Intron= The pieces that are REMOVED Exon= The pieces that are KEPT

C. Translation Occurs on a ribosome

2. tRNA helps “translate” the mRNA into amino acids (the tRNA brings the correct amino acid to the mRNA’s matching code)

How to complete Translation Draw a line after every three letters in the mRNA code. These three letters are called a CODON. Use the chart to translate the codons into amino acids

A – U – G – G – C – A – U – C – G – U – A – A ________ _________ _________ ________

A – U – G – G – C – A – U – C – G – U – A – A Methionine ________ _________ ________

A – U – G – G – C – A – U – C – G – U – A – A Methionine Alanine _________ ________

A – U – G – G – C – A – U – C – G – U – A – A Methionine Alanine Serine _______

A – U – G – G – C – A – U – C – G – U – A – A Methionine Alanine Serine Stop

Review Protein Polymer

V. What if there are problems?

A mutation is any change in the DNA sequence. A. What is a Mutation? A mutation is any change in the DNA sequence.

1. Mutations in Reproductive Cells in gametes (sperm & egg cells) could be passed on to offspring

2. Mutations in Body Cells normal cells (somatic cells) cannot be passed on to offspring

Chromosomal mutations VI. Types of Mutations Gene mutations & Chromosomal mutations

A. Types of Gene Mutations Point mutation-a change in a single base pair in the DNA. May or may not interfere with protein production. i.e. sickle cell anemia THE DOG BIT THE CAT THE DOG BIT THE CAR

Types of Gene Mutations 2. Frameshift mutation-where a single base pair is added or deleted, causing a shift in how the strand will be read.

Many proteins can be affected and will not function properly. THE DOG BIT THE CAT THE DOB ITT HEC AT

B. Types of Chromosome Mutations 1. Deletion-part of a chromosome is left out.

There is a small section of chromosome #5 that has been deleted

2. Insertion-part of a chromatid breaks off & attaches to its sister chromatid.

3. Inversion-part of a chromosome breaks off & reinserts backwards.

4. Translocation-part of one chromosome breaks off & is switched with a piece from a different non-sister chromosome.

One example of translocation is chronic myelogenous leukemia A portion of chromosome 22 switches places with a small fragment from 9

VII. What causes mutations? A. Spontaneous mistakes B. environment any agent that can cause a change in DNA is called a mutagen. (x-rays, UV light, asbestos)

this works well, but is not perfect C. DNA Repair 1. Enzymes in our cells remove the incorrect nucleotides & replace them with the right ones. this works well, but is not perfect

Conclusion: What do mutations ultimately cause? Since DNA is the instructions for making proteins… and mutations are mistakes in the DNA code… the mutations cause ABNORMAL PROTEIN PRODUCTION.