MICROBIO 161 1st Edition Lecture 3 Outline of Last Lecture I The Nature of Disease II Categories of Diseases III The Scientific Method IV Experiments and Theories V Infectious Diseases a Factors VI Life Expectancy Outline of Current Lecture I Cells a Organization of Cells II The Cell Cycle a Checkpoints The Cell III Growth Factors IV Cell Function and Cancer a Characteristics of a Normal Cell and Cancer Cell V Protein Production VI Genetic Code VII DNA Replication These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Current Lecture Every cell has the same DNA The average adult has approximately 100 trillion cells in total 210 types of cells in the human body Organization of cells Tissues groups of cells that perform a similar function Organ groups tissues which perform the same function Organ systems groups of related organs Digestive System 1 Stomach A Acid secreting cells gland B Mucus secreting cells gland 2 Intestines C Muscle cells muscle D Nutrient absorbing cells mucosa The Cell Cycle G1 first growing phase Where most cells spend most of their life Creates protein S synthesis phase When a cell is big enough it begins the process of cell division G2 second growing phase Growth in this has only occurs if the cell notices that it doesn t have all the required components to divide M mitotic phase Actual cell division The Cell Checkpoints Cells have checkpoints to regulate the cell cycle set of questions if any answers to the questions are no the cell cycle pauses until there are enough changes that the answer becomes a yes if yes isn t possible the cell can exit the cycle or begin apoptosis process of programmed cell death G1 Checkpoint Is the cell big enough cell growth Is the environment favorable G2 Checkpoint Is all the DNA replicated DNA replication machinery Is the cell big enough Is the environment favorable M Checkpoint Are all chromosomes aligned on spindle mitosis machinery Growth Factors proteins that stimulate cell growth and division Can be self produced or come from another cell Growth factors attach to a growth receptor and start a signal cascade signaling molecules between cells results in transcription factor activation further results transcription of growth related genes The blue dots resemble the different proteins that eventually turn on the orange transcribing genes DNA holds the recipes for making proteins everything a cell needs to survive is coded in its DNA Chromosomes the cookbooks containing protein recipes Gene an individual protein recipe Protein Production Protein Producti on RNA POLYMERASE RIBOSO MES TRANSCRIBED TRANSLATED AMINO ACIDS Protein Deoxyribonucleic Acid Ribonucleic Acid messenger RNA Transcription copy of DNA RNA translated to Amino Acids DNA and RNA are nuclear chains of nucleotides letters in the DNA RNA genetic alphabet DNA Bases T A C G RNA Bases U A C G Genetic Code DNA sequence of a gene a sentence of 3 letter words codon Thedogwasstuckoutinthesunalldaywaitingforhisfamily Separated into 3 letter bits codons the protein code would read The dog was stuck out in the sun all day waiting for his family the sentence represents a gene each letter corresponds to a nucleotide base each word represents a codon together they code for a specific order of amino acids building blocks peptides for proteins a polypeptide Genotype the process of determining the genetic constitution by examining their DNA sequence Messenger RNA mRNA a large family of RNA molecules that convey genetic information from DNA to the ribosome where they specify the amino acid sequence of the protein products of gene expression Polypeptide chains of amino acids Phenotype the appearance of an organism resulting from the interaction of the genotype and the environment DNA Replication the process of producing two identical strands from one original DNA molecule When cells divide each daughter cells needs a complete copy of the DNA DNA polymerase is the protein that makes the copy Once DNA polymerase makes a copy of the DNA the cell can move forward in the cell cycle DNA reads synthesizes and proofreads Bases have assignments A G C G if they don t go to the correct one then it will more than likely change to the correct one Cell Function and Cancer Every cell in an organism has the same genetic information DNA but cells perform different roles Their roles depend on their function which is determined by the tissue or organ to which they belong A cell s function is guided by a specific set of instructions genes in its nucleus Expression of genes is controlled by transcription factors help cells perform their daily functions and regulate cell growth by controlling gene expression When the instructions genes relating to cell growth and death are wrong mutated the cell may start dividing uncontrollably not die when it should and cancer results Characteristics of a Normal cell Reproduce themselves exactly Stop reproducing at the right time Stick together in the right place Become specialized or mature differentiate Self destruct if they are damaged apoptosis Characteristics of a Cancer cell Don t reproduce themselves exactly Don t stop reproducing at the right time Don t stick together in the right place Don t become specialized or mature differentiate Don t self destruct if they are damaged apoptosis
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