2.Molecular Biology A.Background Gene Subunits Nuckeus DNA DNA Bases A gene is a working subunit of a Gene- DNA molecule. A gene is any DNA segment carrying a particular set of 2m instructions that allows a cell to produce a specific product- typically,a protein such as an mRNA enzyme. Chain of ·Every gene is r made up of Amino Acids thousands,even hundreds of thousands,of chemical bases. ) Protein Ribosome DNA->RNA->Protein Cell Membrane
Gene Subunits • A gene is a working subunit of a DNA molecule. • A gene is any DNA segment carrying a particular set of instructions that allows a cell to produce a specific product— typically, a protein such as an enzyme. • Every gene is made up of thousands, even hundreds of thousands, of chemical bases. DNA->RNA-> Protein 2. Molecular Biology A. Background
2.Molecular Biology A.Background DNA the molecule of life Trillions of cells cell chromosomes Each cell: gene 46 human chromosomes 2 m of DNA 3 billion DNA subunits(the DNA bases:A,T,C,G) 80,000 genes code for proteins that perform all life protein functions 161第
2. Molecular Biology A. Background
2.Molecular Biology B.Mutations and Cancer Gene Mutations Genes can be altered,or mutated,in many ways. Mismatch Deletion The most common:single base mismatch 一 a misspelling.Also,a single base may be dropped or added. Sometimes:large pieces of DNA are mistakenly repeated or deleted Repetition Deletion
• The most common: single base mismatch — a misspelling. Also, a single base may be dropped or added. • Sometimes: large pieces of DNA are mistakenly repeated or deleted Gene Mutations Genes can be altered, or mutated, in many ways. 2. Molecular Biology B. Mutations and Cancer
2.Molecular Biology B.Mutations and Cancer Acquired mutations Nomal Spemm are changes in DNA Bone Cell Egg that develop during Mutation a person's lifetime. Occurs Fertilized Mutation mutations occur in Egg Occurs Mutation DNA all the time, Body especially during Altered Cells of cell division,a cell Gene Offspring has the remarkable ability to fix them. But if DNA repair mechanisms fail, Reproductive Pancreas mutations can be passed along to future copies of Nommal the altered cell. Altered Bone Cells Bone Cells Bone Brain Acquired Mutations Hereditary Mutations
Acquired mutations are changes in DNA that develop during a person's lifetime. mutations occur in DNA all the time, especially during cell division, a cell has the remarkable ability to fix them. But if DNA repair mechanisms fail, mutations can be passed along to future copies of the altered cell. Acquired Mutations Hereditary Mutations 2. Molecular Biology B. Mutations and Cancer
2.Molecular Biology B.Mutations and Cancer Nuceeus DNA A sound健康的body depends DNA on the continuous interplay of Gene- Bases thousands of proteins,acting together in just the right amounts and in just the right A places-and each properly functioning protein is the product of an intact gene. mRNA Many,if not most,diseases have their roots in our genes. Chain of More than 4,000 diseases stem Amino Acids from altered genes inherited from one's i mother and/or father. Protein Ribosome Altered DNA->Altered Protein Cell Membrane
Altered DNA->Altered Protein A sound健康的 body depends on the continuous interplay of thousands of proteins, acting together in just the right amounts and in just the right places—and each properly functioning protein is the product of an intact gene. Many, if not most, diseases have their roots in our genes. More than 4,000 diseases stem from altered genes inherited from one's mother and/or father. 2. Molecular Biology B. Mutations and Cancer