Molecular Genetics

DNA Define the term DNA Deoxyribonucleic acid Why is DNA important? Stores our genetic material Describe the structure of DNA Double helix, 4 types of nucleotides (ATCG) Describe the structure of a nucleotide Phosphate group, deoxyribose, nitrogenous waste How do the bases pair? A – T, C - G

Structure of DNA

DNA continued How are the two strand bound together? Hydrogen bonds between bases How does DNA store our genetic material? As genes How do genes differ? Sequence of nucleotide bases

Replication Why do we want DNA to replicate? For cell division (growth) How does replication begin? Breaking of Hydrogen bonds How are those bonds broken? Helicase How are the two new strands synthesized? DNA polymerase How do the two strands compare to the original strand? Exactly the same

Replication continued Define semi-conservative replication Each original strand acts as a template for the new strands to be formed Each new strand is a combination of one original and one newly synthesized strand Write the complementary strand: ATTTGCCACGGGAATACG Diagram the replication of this strand of DNA

Replication of DNA

DNA replication

Protein Synthesis Where are proteins made in a cell? Ribosome Where do the instructions for the protein come from? DNA/Gene How does the gene get to the ribosome? mRNA (messenger RNA) What process creates mRNA? Transcription

Transcription How is the gene exposed to make a RNA copy? Break hydrogen bonds How is mRNA synthesized? RNA polymerase Where does transcription take place? Nucleus Where does mRNA go? Ribosome

Transcription

Translation How does the ribosome use the mRNA? Guide to build the protein How do amino acids get to the ribosome? tRNA – transfer RNA How do the tRNAs differ? Each carries a specific amino acid Describe the structure of tRNA Anticodon corresponds to a specific amino acid

Translation continued How does the ribosome use the mRNA and tRNA to synthesize proteins Ribosome allows tRNA to bind with codon (triplet of bases on mRNA) if bases are complementary Why is it beneficial that the mRNA can be re-used?

Translation

Genetic Engineering Define selective breeding Having organisms of the same species breed to get offspring with desirable traits Drawbacks to selective breeding No guarantee the traits wanted will be present in the offspring

Genetic Engineering II Define Hybridization Breed two closely related organisms to get desired traits Example: liger, horse + donkey = mule; husky and wolf = big dog!! Define Inbreeding What are some problems with inbreeding? Non-desirable traits (recessive usually) are expressed more often in the offspring

Genetic Engineering III Define transformation in terms of genetic Define recombinant DNA DNA of two or more species that are combined together (bacterial plasmid with human gene; glow in the dark rabbit, etc.) How can we produce recombinant DNA? Describe the function of restriction enzymes in creating recombinant DNA

Transformation

Genetic Engineering IV Define the term clone Describe a procedure to make a clone Genetically how would clones from one donor compare Would they all look the same? Explain No, different genes may be activated causing the clone to look different Can you breed clones from one donor? No they are all the same sex

Cloning Techniques