| A | B |
|---|
| DNA | Deoxoribose Nucleic Acid |
| Code of life | codes for proteins essential to the health of the organism |
| What is backbone made of? | Made of alternating phosphorus and sugars |
| What is DNA made of? | Made of matching Nitrogen bases - Adenine to Tyrosine and Cytosine to Guanine |
| Nucleotides | 5 carbon sugar, phosophate and a Nitrogen base |
| What is each nitrogen base bonded by? | Bonded by weak Hydrogen bonds (glue stick of nature) - bonds are weak for DNA to replicate or transcribe |
| What was Griffith's Major Experiment | 1928-have to determine why certain bacteria give people pneumonia, something was able to be passed from harmful bacteria to harmess ones, making them DEADLY; took bad bacteria into a mouse-dead, took good bacteria into a mouse-was alive, injected heated bacteria-alive, mixed dead and good bacteria=dead |
| What was Griffith's Major Conclusions? | Genetic information could be from one bacteria to another=transformation |
| What was Avery's Major Experiment? | 1944, repeating experiments of Griffiths, wanted to find out what the molecule is that was transforming harmless bacteria into killers, used enzymes to break down different molecules |
| What was Avery's Major Conclusion? | Protein destroying enzymes did not affect transformation, DNA stores and transmits genetic info from one generation to the next |
| What was Hershey's and Chase's Major Experiment? | 1952-bacteriophages (infected bacteria), knew that viruses infect cells by injecting own DNA inside, radioactivety marked the viral DNA, bacteria contained radioactive material |
| What was Hershey's and Chase's Majore Conclusions? | DNA is the genetic material of the viruses, not the protein coat |
| What was Chargaff's Major Experiment | 1949-wanted to know how DNA was bonded together by examining the four base pairs, took DNA from different sources and saw percentages of C, G, A and T |
| What was Chargaff's Major Conclusions? | Chargaff's Rules= A goes with T; G goes with C |
| Franklin's Experiment? | 1952-use x-rays to study DNA, show a pattern |
| Franklin's Conclusions? | DNA is twisted around each other in a helix |
| What was Watson's and Crick's Major Experiment? | 1953-3D models of DNA using wire and cardboard, shown a copy of Franklin's x=ray picture |
| What was Watson's and Crick's Major Conclusions? | DNA=a double helix; 2 strands of DNA coild around nitrogenous bases |
| What two nucleic acids play important roles in biology? | Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) |
| Waht are the monomers of nucleic acids? | Nucleotides |
| What is each nucleotide made up of? | A sugar, a phosphate group, and a nitrogen-containing base |
| What is the sugar in DNA? | deoxyribose |
| What are the nitrogen bases in DNA? | Adenine, thymine, cytosine, and guanine |
| Where are exactly the same sequences of DNA? | Are found in every cell nucleus of the same organism |
| When does DNA replicate? | Before each mitotic cell division |
| Why is DNA replication essential? | Essential in terms of preserving genetic continuity of cells for repair and reproduction; without this, all life would cease to exist |
| Where does replication start? | Starts at the free-phosphate end and moves towards the free sugar end |
| What happens during DNA replication? | DNA helicase, an enzyme, "unzips" the DNA polymer by breaking the hydrogen bonds that hold the pairs of bases together; DNA comes apart in the middle between the base pairs; DNA polymerase, another ezyme, binds free-floating nucleotides to the exposed bases to produce two new complete molecules of DNA |
| What do DNA plymerase also do? | Also "proofread" the DNA to make sure it is a perfect copy |
| What does DNA Ligase do? | Seals up newly laid bases by creating new hydrogen bonds |
| What does DNA Gyrase do? | Winds the new DNA strands back into helix form |
| What is DNA replication? | Semi-conservative meaning one strand of the original DNA molecule is part of the new DNA molecule |
| What is called a mutation? | Any change to the Nitrogen Bases in DNA; change the DNA, changes the mRNA, may change protein, may change trait |
| What is a point mutation? | Change in a single base pair in DNA (substitutions) |
| How many amino acids do point mutations affect in the protein? | 1 amino acid |
| What happens to the protein in a point mutation? | Causes no change in the function of the protein or partial function of the protein; ex: sickle cell anemia |
| Transversion mutation | Causes a change in purine (A, G) with a pryimidine. (C, T); creates a missense mutation, that changes the amino acid |
| Transition mutation | Causes a change in the bases, but no change in the amino acid; due to a "Wobble" in the DNA code |
| Base mutation | mutation causes a change with a new stop codon in the wrong place; creates a nonsense mutation that changes the amino acid to STOP |
| Frameshift mutation | Single base pair is added or deleted and shifts the reading of the codons |
| Insertion | Adding a base |
| Deletion | Removing a base |
| How many amino acids do frameshift mutations affect in the protein? | Affect many amino acids in the protein; causes a non-functional protein; ex: PKU |
| Chromosomal mutations | Any change in the structure or number of chromosomes |
| deletion | Part of a chromosome is removed |
| duplication | Part of a chromsome is repeated |
| inversion | Part of a chromosome breaks off and is reinserted backwards |
| Insertion and translocation | Part of a chromsome breaks off and attaches to another chromosome |
| How many ways can you create a change in the genetic code? | Some can mutate certain bases or genes; some can turn on the wrong expression of certain genes |
| Beneficial mutation | The natural environment can favor certain changes in allelic frequencies. natural selection |
| 3 possible outcomes for a mutation in an individual/gene pool | Beneficial, harmful, neutral |
| Radiation | Alters genes through mutation and can turn on oncogenes (genes promoting cancer) |
| Why is lead poisoning a harmful mutation? | Modifies ALAD gene which alters hemoglobin protein synthesis |
| Viruses-lifetime | Can live in the body for long periods of time up to an organism's entire lifetime |
| Viruses-DNA | Some viruses have been linked to changes in the DNA causing diseases and disorders: ex: Epstein Barr virus has been llinked to certain types of cancer |
| What are viruses? | Non-living particles of nucleic acid, protein, and some lipids that cause influenza |
| Viruses-named | Named after their disease or discoverer (Bacteriophages-attack Bacteria) |
| Viruses-discovered | Likely evolved later since they are dependent on living things |
| Lysogenic cycle | Virus attaches to host cell, inserts viral nucleic acid and inserts in into the host cell's chromosome (prophage), gets replicated as host cell divides (through mitosis) Can remain inactive for a long period of time |
| Lytic cycle | Starts as the lysogenic cycle until triggered, takes over cell machinery to make virus only (Chops up cell's dNA to shut down all defenses) Viruses are assembled int eh host cell, burst out of the host cell releasing new virus |
| Why is DNA the code of Life? | The sequence of DNA codes for proteins; the nucleus of a human cell contains more than 6 feet of DNA |
| How does DNA get packed so small? | Chromosome packaging |
| Chromatin | Short region of DNA double helix |
| Histones | Beads on a string form of chromatin |
| Nucleosomes | 30-nm chromatin fibre of packed nucleosomes |
| Coils | Section of chromosome in an extended form |
| Super Coils | Condensed section of chromosome |
| Chromosomes | Entire mitotic chromosome |
| Why can DNA be copied or replicated? | Because DNA paires A to T and G to C |
| Complementary | Each strand can be used to copy the other strand |
| Overall process of DNA replication | 1 DNA strand makes 2 DNA strands and semi conservative; used during mitosis; first part of the central dogma of cell biology; allows for genetic continuity and DNA to be in EVERY body cell |
| First step DNA replication | the helix unwinds into a simple, unfolded DNA strand |
| Second step DNA replication | DNA helicase breaks the hydrogen bonds between the two strands |
| Third step DNA replication | The 2 single strands (replication forks) serve as templates for base pairing (called Semi-conservative) |
| Fourth step DNA replication | DNA Polymerase adds free nucleotides to both sides of the DNA; it also "proofreads" the DNA to make sure it is a perfect copy |
| Fifth step DNA replication | DNA Ligase reforms the Hydrogen bonds between the 2 new strands and then recoil with DNA Gyrase |
| 4 major ways is DNA different than RNA? | DNA is double stranded and RNA is single stranded; the Thymine in DNA is replaced with Uracil in RNA; Deoxyribose sugar of DNA is Ribose sugar in RNA; DNA cannot leave the nuclus where the RNA can leave the nucleus |
| Messenger RNA | carries the gene to made into protein; split into a 3 base code called codons |
| Codons | 3 base code |
| Transfer RNA | transfers amino acids to the mRNA and match the codons with anticodons |
| Anticodons | What you attach the codons to |
| Ribosome RNA | makes up ribosomes that "read" mRNA and assembles tRNA (with their amino acids) to making a protein |
| Transcription step 1 | RNA polymerase binds to a gene's promoter-a sequence of DNA that signals the "start" for transcription |
| Transcription step 2 | RNA polymerase unwinds the DNA exposing the base pairs |
| Transcription step 3 | RNA polymerase "reads" the DNA, adding base pairs (change to A-U) to a single strand |
| Transcription step 4 | RNA polymerase hits a "stop" sequence of bases and ends transcription |
| Transcription step 5 | DNA recoils and the mRNA leaves the nucleus |
| Introns | Some parts of the DNA sequence that aren't involved in coding for proteins; must be removed from mRNA |
| Exons | Parts of the gene that will be expressed |
| Translation step 1 | A piece of mRNA leaves the nucleus and attaches to a ribosome at the ER |
| Translation step 2 | The ribosome finds "AUG" and brins in tRNA that matches the start codon; codon AUG matches tRNA anticodon UAC with the amino acid methionine; always first amino acid of a new protein |
| Translation step 3 | The next tRNA enters and the ribosme attaches (with a peptide bond) the next amino acid forming a polypeptide chain |
| Translation step 4 | The ribosome keeps bringing in new tRNAs until it hits a stop codon |
| Translation step 5 | The complete polypeptide goes to the Golgi Body to become a final protein |
| Gene regulation | The process by which different genes are turned on and off, so certain proteins are expressed in different types of cells and different times in cells |
| Genes are what...DNA | Genes are CODING sequences of your DNA |
| What does expression of a gene mean? | Means it is being transcribed and actively translated into a protein |
| gene regulation with expressions | Expression can be turned off=Gene regulation |
| Every cell in an individual body has the exact same copy of what? | Of DNA (But only 3% of genes are expressed) |
| Most people almost have what? | the same DNA code |
| Why do people look unique? | Because there are very few changes in the genome; our environment may also have an effect on gene expression |
| Function | Different cells have different genes expressed and code for different proteins which specialize their function |
| Four regions of DNA control the production of a protein | structural gene; operator; promoter; a regulator |
| Structural gene | Holds the codons for the amino acid sequence found in the enzyme |
| Operator | region right in front of the structural gene |
| Promoter | Region where the RNA polymerase will bind to the DNA ( To start Transcription) |
| Regulator | Gene which has a role in controlling the transcription from the structural gene (or active protein) |
| Operon | The combined region of the operator and structural gene |
| Regulatory sequences | Kind of like a thermostat; turn the gene on and off depending on what the environment is like; just like a thermostat turns the heater on or off depending on the temperature of your house |
| Sugar | The energy for living things, but it needs to be processed for its use |
| The Lac Operon | Works by suppressing expression of genes that metabolize lactose when glucose is available |
| What happens when glucose is present? | The repressor prevents the proteins (enzymes) to break down lactose from bein transcribed and translated |
| Repressor and RNA Polymerase | Now the repressor cannot physically bind to the Lac Operator; RNA Polymerase can now attach tot he promoter allowing for transcription of the genes downstream wich will then be translated into protein |
| What happens when the lactose is present? | It binds to the repressor changing its shape |
| Unregulated Gnen Expression | 1. There is a mutation in the regulatory sequence that keeps a protein from biding to it; there is a mutation in the sequence of a protein that usually binds to a regulatory sequence |
| What is an example of dangerous unregulated gene expression? | Cancer |
| When is the gene regulation the most important during the life of an organism? | Embryonic Devevelopment |
| What is hair? | Protein (dead cells) keratin, melanin- made through Protein Synthesis (transcription and translation) |
| How does this happen? | Testosterone; rising testosterone levels cause responsive tissues (receptors) to activate |
| Why do Men grow facial hair? | Y chromosome; production level of women is not enough to trigger the receptive complex |
| Epigentics | The study of the modifications to genes, which do not involve changing the underlying DNA |
| What kind of changes are epigentics? | Inheritable changes (Within a cell line or within generations of a family) |
| Where are epigentic changes? | in phenotype (appearance) or changes in gene expression |
| What are epigenetics caused by? | Caused by non-genetic factors cause the organism's genes to behave (or "express themselves") differently |
| Genetic Engineering | The process of making changes in the DNA code of living organisms |
| Indirect | Arificial selection, selective breeding, inbreeding |
| Direct | Transfomation, GMOs, Transgenic Orgaisms |
| Biotechnology | Any process that uses our understanding of living things to create a product |
| ELSI | Ethical, Legal and Social Issues associated with Biotech and GE |
| Artificial Selection | The internantional breeding for certain traits, or combination of traits. Instead of selection by the environment (natural selection) it is selection by humans |
| Selective Breeding | Allowing only animals with desired traits to reproduce |
| Hybridization | Crossing (reproducing) different individuals to bring together the best of both organisms. A Hybrid are often hardier and stranger than the parents |
| Inbreeding | Breeding of individuals with similar characteristics to maintain these traits. Can be dangerous causing an increased probability of recessive alleles coming together |
| DNA transformation | An oroganism takes up DNA from another organism to express a gene of interest |
| Steps of DNA transformation | Map the chromosomes of an organism or plasmid; locate the specific gene of interest on the chromosome to insert into the plasmid; cut the plasmid and gene DNA with restriction enzymes to create sticky ends; isolate and produce many copies of that gene (PCR); insert gene into a plasmid then into the new organism's DNA and regulate the expression |
| Recombinant DNA | DNA produced by combining DNA from two different organisms |
| Transgenic organisms or GMOs | Organisms with DNA from others |
| Examples of Genetic Engineering | Production of Human Insulin;Golden Rice;Bt Corn; Spidersilk; cutting and pasting:Fluorescent; organisms growing body parts on animals |
| DNA extraction | Isolating DNA from a sample of tissue |
| Steps of DNA extraction | Spin the sample to trap cells at the bottom; add a lysis solution to open up the cells; add isopropanol to the tube to make the DNA appear in the solution (floats); remove the DNA layer and the centrifuge again to force the DNA to the bottom of the tube; wash the DNA with ethanol and preserve it in buffer solution |
| Polymerase Chain Reaction (PCR) | Uses DNA polymerase (enzyme) to create thousands of copies of a gene |
| Steps of PCR | MELT-denature the DNA (DNA is melted at 95 degrees C); STICK prime the DNA for adding bases (Primers anneal (match-up) at 60 C); ZIP-add bases to the primed strands. (taq Polymerase extends (adds more mases to) the strand at 72 C) REPEAT steps 1 through 3 until desired number of DNA compies is reached |
| Gel Electrophoresis | Seperates DNA fragments through a gel using electricity |
| Steps of G.E. | Operates by seperating DNA fragments according to their base pair lenghts. DNA has a negative charge so it moves to the positively charged end of the electrified gel; large fragments move slowly where as smaller fragments move quickly. The gel is then exposed to UV light to show the locaiton of the DNA fragments |
| DNA Fingerprinting | Method of DNA analysis which identifies individuals by examining DNA fragments using gel electrophoresis |
| DNA variation : SNP | Variations in the genetic code between different individuals |
| Cloning | A member of a population of genetically identical cells produced from a single cell. In 1997, Ian Willmut presented "Dolly", the first cloned mammel |
| Gene Therapy | Process of changing a gene that causes a genetic disorder. USES VIRUSES |
| Mass Spectromety | Determine the weight of molecules found in a given sample. Once sorted, we can not only identify which molecule is present in the sample, but also how much of it is there. |
