BIOL 270 - 51 Lecture Chapter 1 (Fall 2024) PDF

General Genetics BIOL 270 - 51 Lecture Chapter 1 Lecture hours: C6 – 0005 (Tue & Thurs, 3:30 PM to 4:20 PM) Office hours: C6 – 2043 (Tuesday, 1 PM to 2 PM) Dr Haslina Razali or by appointment (2 days ahead) Fall 2024 Introduction to Genetics in th...

General Genetics BIOL 270 - 51 Lecture Chapter 1 Lecture hours: C6 – 0005 (Tue & Thurs, 3:30 PM to 4:20 PM) Office hours: C6 – 2043 (Tuesday, 1 PM to 2 PM) Dr Haslina Razali or by appointment (2 days ahead) Fall 2024 Introduction to Genetics in the Twenty-First Century CHAPTER CHAPTER 1 Genetics: The study of biological information CHAPTER OUTLINE ▪ 1.1 DNA: The Fundamental Information Molecule of Life ▪ 1.2 Proteins: The Functional Molecules of Life Processes ▪ 1.3 Complex Systems and Molecular Interactions ▪ 1.4 Molecular Similarities of all Life-Forms ▪ 1.5 The Modular Construction of Genomes ▪ 1.6 Modern Genetic Techniques ▪ 1.7 Human GeneticsCopyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 2 al., 4th ed., Chapter 1 The biological information in DNA generates an enormous diversity of living organisms Fig. 1.1 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 3 al., 4th ed., Chapter 1  Three levels of biological information DNA (Deoxyribonucleic acid) Macromolecule that belongs to the nucleic acids Made up of nucleotides Has information to make proteins Proteins Macromolecules made of amino acids Amino acid sequence determined by DNA sequence of gene Biological systems Network of interactions between molecules or groups of cells Accomplish coordinated functions Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 4 al., 4th ed., Chapter 1  Who discovered DNA? Friedrich Miescher (1869) Extracted a weakly acidic, phosphorus-rich material from nuclei of human white blood cells Called nuclein Major component of nuclein is DNA Deoxyribonucleic acid Based on a sugar (deoxyribose) and it’s acidic nature found in the cell’s nucleus https://www.youtube.com/watch?app=desktop&v=UFChDmR65kE  Complementary base pairs are a key feature of the DNA molecule DNA is comprised of 4 nitrogen bases: guanine (G), adenine (A), cytosine (C), and thymine (T), deoxyribose (pentose sugar) phosphate (PO43─) G – C and A – T hydrogen bonds between each strand of the double helix The two strands of the double helix are in opposite orientation Fig. 1.2 (antiparallel) 1 2 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 6 al., 4th ed., Chapter 1  Where is DNA? Inside all Cells! Inside nucleus of each cell (except…) = nuclear DNA (nDNA) Inside mitochondria of each cell = mitochondrial DNA (mtDNA) Inside chloroplast of each plant cell = chloroplast DNA (cpDNA) Fig. 1.2 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 7 al., 4th ed., Chapter 1  Where is DNA? Inside all Cells! Inside nucleus of each cell (except…) = nuclear DNA (nDNA) Inside mitochondria of each cell = mitochondrial DNA (mtDNA) Inside chloroplast of each plant cell = chloroplast DNA (cpDNA) Nuclear DNA of somatic (body) cells contains _______ of DNA (i.e. ___ sets of chromosomes) — one from father, one from mother 2n = diploid , but __________ for sperm and egg cells (gametes) Plastid DNA (= mtDNA & cpDNA) contains only _____ DNA (i.e. ___ set of chromosomes) — usually from the mother n = haploid Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 8 al., 4th ed., Chapter 1  Information of DNA DNA contains all the information necessary for life: to build cells, body functions (e.g. metabolism), movement, etc. This information in encoded in Genes Genes are parts (regions) of the DNA that code for (hold information for) making proteins. One gene usually holds the information to make one protein. Inside Nucleus Inside Cytosol Eukaryotic cells Transcription Translation DNA (Gene) RNA Protein Fig. 1.2 Replication Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 9 al., 4th ed., Chapter 1  Organization of genetic information in cells ❑Genes are sequences of DNA that encode (= code for) proteins ❑Chromosomes are structures of DNA and proteins. The DNA coils up around proteins to form chromosomes before cell division. Chromosomes are needed to equally divide DNA. ❑Genome is the whole collection of chromosomes (and genes) in all cells of an organism ❑The human genome: ❑ 23 pairs of chromosomes (22 pairs autosomes & 1 pair of sex chromosome) ❑ 3 x 109 base pairs ❑ Encodes 20,000 – 30,000 genes Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et Figure 1.4 10 al., 4th ed., Chapter 1  The information in DNA is one-dimensional and is digital Biological information is encoded in the nucleotide sequence of DNA and each unit of information is discrete DNA sequence can be handled by computers Automated DNA sequencers can sequence about 106 base pairs/day New technologies can sequence even more DNA per day Fig. 1.3 Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 11 al., 4th ed., Chapter 1  Proteins are polymers of hundreds to thousands of amino acids There are 20 different amino acids Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 12 al., 4th ed., Chapter 1  Proteins are polymers of hundreds to thousands of amino acids There are 20 different amino acids Information in DNA of a gene dictates the sequence of amino acids for the protein The order (sequence) of amino acids determines the type of protein and its three dimensional structure (= conformation). Diversity of three-dimensional structure of protein generates an extraordinary diversity of protein functions Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 13 al., 4th ed., Chapter 1  The amino acid sequence determines the three-dimensional shape of the protein Chemical formulas for two Three-dimensional shapes of two amino acids proteins Figure 1.5a Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display Hartwell et 14 Figure 1.5c al., 4th ed., Chapter 1  Genetics explains the mechanisms that determine the inheritance of traits 1- Genes are the basic units of heredity Heredity is the way that genes pass on traits from parents to offspring Genes are passed from one generation to the next 2- Genes are the basis of every heritable trait, e.g. color of hair, skin, and eyes 15  Inheritance: Mendel’s Legacy Gregor Mendel’s first experiments with garden peas showed how genetic information is ‘inherited’: Copyright © The McGraw-Hill Companies, Inc. Permission required 16 to reproduce or display Hartwell et al., 4th ed., Chapter 2  Inheritance: Mendel’s Legacy Gregor Mendel’s first experiments with garden peas showed how genetic information is ‘inherited’: Copyright © The McGraw-Hill Companies, Inc. Permission required 17 to reproduce or display Hartwell et al., 4th ed., Chapter 2  Inheritance: Mendel’s Legacy Gregor Mendel’s first experiments with garden peas showed how genetic information is ‘inherited’: AA aa Two alleles: A = dominant a = recessive Aa Genotypes: AA = homozygous dominant aa = homozygous Aa recessive aa AA AA aa Aa = heterozygous Aa Aa aa AA Aa aa 18  Genetics explains the mechanisms that determine the inheritance of traits What are these genotypes called? A A B B 19  Genetics explains the mechanisms that determine the inheritance of traits What are these genotypes called? List the genotypes. A A B B 20  Genetics explains the mechanisms that determine the inheritance of traits What are these genotypes called? a a b b 21  Genetics explains the mechanisms that determine the inheritance of traits What are these genotypes called? List the genotypes. a a Eye colour gene: aa Hair colour gene: bb b b 22  Genetics explains the mechanisms that determine the inheritance of traits What are these genotypes called? A a B b  Genetics explains the mechanisms that determine the inheritance of traits What are these genotypes called? List the genotypes. A a Eye colour gene: Aa Hair colour gene: Bb B b