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Concept map chapters 10-12: Jenny, Chie, Deep - Coggle Diagram
Concept map chapters 10-12: Jenny, Chie, Deep
Chapter 10 - Molecular Biology of the gene
Big Idea 1: The Structure of the Genetic Material
Today scientist can manipulate DNA to alter the heritable traits of cells but back then the molecular basis of DNA was a mystery
Back then, biologists knew that gene were located on the chromosome
2 leading components of chromosomes
DNA
Through bacteria and virus experiments they learned that DNA played the role of heredity
Protein
Until 1940s people sided more with proteins since it was more complex (20 different amino acid building blocks) whereas DNA was made from 4 nucleotides
Frederick Griffith
Attempted to develop a pneumonia vaccine using 2 strains of bacteria but learned that live bacteria can inherit genes from dead bacteria
His work laid out the foundations to find the chemical basics of heritdity
Alfred Hershey and Martha Chase performed experiments around bacteriophages/phages that showed that DNA is genetic material
Connection: Alfred and Hershey's work laid out the foundations to find out about future discoveries on DNA and advance technology
After the confirmation that DNA is the molecule of heredity, they began to study its structure
Nucleic acids
DNA
RNA
Made of monomers and polymers called nucleotides
DNA polynucleotides are a nucleotide polymer chain
Nitrogenous bases
sugar phosphate backbone
ribose
deoxyribose
DNA (A, C, T, G)
RNA (A, C, U, G)
Rosalind Franklin did x-ray images on DNA
Crick and Watson stole one of the images and deduced that dna formed a double helix
They constructed 3D models using the x-ray image and figured out that there are based in DNA and RNA
They won a Nobel prize but Rosalind didn't win one and died early
Big Idea 2: DNA Replication
Primary function of DNA is to encode and store genetic info by passing it on during cell division and reproduction
Ch 1-9 Connections: Structure and Function. The structure of the double helix such as the bases and strands play a role in its function of DNA replication. Specific pairings of bases allowed DBA to be copied,
Connection: Similarly to how cells can divide and reproduce, you can clone/create cells artificially through many means
Specific base pairings in the double helix of DNA allowed it DNA to be copied
A pairs with T
G pairs with C
Enzymes form nucleotides to form new DNA strands.
The model for a DNA replication is called a semiconservative model
DNA replication creates replication bubbles.
3' and 5' ends
Daughter strands are called DNA polymerase
An enzyme called DNA ligase links the pieces together in a single DNA
Big Idea 3: The Flow of Genetic Information from DNA to RNA to Protein
Proteins are the link between genotype and phenotype
However, a gene does not build a protein directly, it dispatches information to RNA to protein synthesis
Transcription
Translation
Connection: As a gene dispatches information to RNA to make a protein, it is being managed through gene regulation.
The flow of infromation from gene to protein is based on a triplet code
Codons
During the 1960s, biologists used electrical experiments to crack the genetic code
messenger RNA (mRNA)
Encodes amino acid sequences by conveying messages of DNA to translation
mRNA is transcribed from DNA and then translated into the polypeptides
Prokaryotic cells
Transcription and translation occur in both the cytoplasm
Eukaryotic cells
Before leaving the nucleus as mRNA, eukaryotic cells transcripts are modified ins everal ways
Cap and tail
3' to 5' tail
Introns
Exons
RNA splicing
tRNA
anticodon
rRNA
Translation is divided into 3 phases
Initiation
Start codon
P-site
Elongation
The anticodon of a tRNA pairs with a mRNA codon in the a site
Add on of amino acid
Translocation of tRNA
Continues until it reaches a stop codon
Termination
Chapter 1-9 Connection - Flow of Information: When you put the whole process of DNA going to RNA and becoming a protein it demonstrates this theme. The information flows from one place to another to get copied and used.
Mutations
Types
Silent Mutation
Missense Mutation
Nonsense Mutation
Frameshift Mutation
Can be caused by mutagens
Physical Mutagens
High Energy radiation
X rays
Ultra violet light
Chemical Mutagens
Cause by DNA replication errors
Cancer can be caused by mutations
Big Idea 4: The Genetics of Viruses and Bacteria
Virus
Capsid
Can reproduce only inside cells
Replication cycle of phage T2
Lystic cycle
Lysogenic cycle
Chapter 1-9 Connections - Structure and Function: The structure of the viruses allow it to easily invade and effect both animals and plants.
Emerging viruses
Chapter 1-9 Connection - Evolutionary Connection: Viruses are evolving and getting stronger against our vaccines.
Common ones
HIV
A type of retrovirus
Reverse Transcriptase
AIDS
Prions are infection proteins
Caused by misfolding
Diseases
Scrapie in sheep
Mad cow disease
Kuru
Can take 10 years for symptoms to develop
Not destroyed in food or normal cooking temperatures
No known cure
Bacteria
Can transfer DNA 3 ways
Transformation
Transduction
Conjugation
F factor
Plasmids
R plasmids
Chapter 11 How Genes are Controlled
Big Idea 1 Control of Gene Expression
Gene Regulation
Turning on and off genes to help respond to environmental changes
A gene that is being turned on is being transcribed into mRNA and translated into protein molecules
Can occur on the chromosomal level
X chromosome inactivation
Barr body
Gene expression
How genetic info flows from gene to protein
The control of gene expression makes it possible for genes to produce specific kinds of proteins when and where they are needed
Our earliest understanding of gene expression came from studies of bacterium
Control Sequences
Promoter
Operator
Operon
Transcription is turned off because of a repressor
Bind to the operator
Physically blocks the attachment of RNA polymerase to the promoter
Regulatory gene
Located outside promoter
Codes for repressor
expressed continually
Activators
Proteins that turn operons on by binding to DNA and stimulating gene transcription
Eukaryotic chromosomes can be chemically modified to help regulate gene expression
The addition of methyl (CH3) groups to some amino acids in histone proteins can cause chromosome to become compact which reduces transcription
Adding acetyl groups (-COCH3) opens up the chromatin structure which promotes transcriptions
DNA can be chemically modified to regulate gene expression
Adding a methy group to DNA bases
Epigenetic inheritance
Modifications to DNA and histones that can passed down to future generations
Reversible
Eukaryotic RNA polymerase requires
Transcription factors
Enhancers
Additional opportunities for gene expression regulation
Breakdown of mRNA
Initiation of translation
Protein processing
Noncoding RNAs play multiple roles in controlling gene expression
MicroRNAs (MiRNAs)
Forms a complex with one or more proteins
The complex can then bind to any mRNA molecule with at least 7-8 nucleotides of complementary sequence
The complex degrades to target mRNA
The complex blocks translation
Small Interfering RNAs (siRNAs)
Similar in size and function to miRNA
Both can associate with the same proteins and produce similar results
Subtle differences between miRNA
Blocking of gene expression by siRNA is called RNA interference (RNAi)
Our earliest understanding of gene control came from studies of bacterium from French biologist Francois Jacob and Jacques Monod with E. Coli
Cellular Differentiation
Eukaryotes
Most vital during development of embryo from a zygote
Relationship between gene expression and embryonic development came from a fruit fly study
They determined which end of the egg cell becomes the head and which becomes the tail
Chapter 1-9 Connections: Interactions. 1. Unfertilized egg cells and cells adjacent to it interact with each other to form gene expression
2.Localization of mRNA will define the animal's head-to-tail tail axis. Egg becomes fertilized and development takes place.
Subdivision of embryo body into segments. Fly body takes shape
Homeotic gene regulates group of other genes that determine anatomy
Eventual outcome of fly body
DNA packing
Histone proteins
Half the mass of eukaryotic chromosomes
Prokaryotes have analogous proteins but lack the degree of DNA packing seen in eukaryotes
Levels of DNA packing
Histones attach to the DNA double helix to form a 10-nm fiber
Nucleosome
Beaded string coils into a 30 nm fiber
Higher levels inactivate genes for the long run
Blocks gene expression by preventing RNA polymerase and other transcription proteins from contacting the DNA
Biologists can now study large expressions of genes
Nucleic acid hybridization
DNA microarray
Chapter 1-9 Connection - Flow of Information: Cell to cell signaling via proteins or molecules carry messages from signaling cells to receiving cells to coordinate cellular activities.
Signal Transduction Pathway
The cell sending a message secretes a signaling molecule
Molecule binds to a specific receptor proteins in the plasma membrane
Binding activates relay proteins
Last relay molecule activates transcription factor
Transcription factor for a specific gene is activated
Translation of mRNA produces a protein that performs perform functions received from the signal.
Chapter 1-9 Connection - Evolutionary Connection: Cell signaling began during the evolution of life on earth where microorganisms sent out signals to mate with one another.
Big Idea 2 Cloning of Plants and Animals
Most cells express only a small percentage of their genes
Plant clones shows that differentiated cells may retain all of their genetic potential
totipotent
Clone
Animal cloning
Regeneration
Nuclear transplantation (technique used for reproductive cloning)
1, Replacing an egg cell or zygote with a nucleus from an injected adult somatic cell
Repeated cell division
Implanted into uterus of a surrogate mother
Cloned a sheep named Dolly
Demonstrated that the differentiation of animal cells is achieved by changes in gene expression rather than permanent changes in genes
Benefits of animal cloning
Improve agiculture
Improve pharmaceutical drugs
Transplants to save human lives
Restock endangered animals
Cons of animal cloning
Some critics argue that cloning does not increase genetic diversity and isn't important
Health of cloned offspring
Practicality issues
Ethical issues rise with humans and whether or not they should be cloned now that animals are being cloned
Connection: Scientific advancement is dependent on society and what they want to know, need to learn, and allow to happen.
Therapeutic cloning
Goal is to treat disease and supply cells for the repair of damaged or diseased organs
Embryonic stem cells
Adult stem cells
Rare success
Ethical issues
Big Idea 3 The Genetic Basis of Cancer
Cancer
A type of disease where the control mechanisms for cell growth have malfunctioned
Oncogene
Cancer causing virus gene
Proto-oncogene
Founded from chicken cancer causing chicken virus
A normal healthy gene that if changed can become a cancer causing oncogene
Causes
Virus
Mutation
Growth factor
Error in DNA replication
Tumor supressing genes
Encode proteins that prevent uncontrolled cell growth
Any mutation that decreases this activity can give you cancer
Life style choices can reduce the risk of cancer
Carcinogens
UV radiation
Tobacco
Fruits, veggies, and vitamins reduce risk
Chapter 12 - DNA technology and Genomics
Big Idea 1: Gene cloning and editing
Biotechnology
The manipulation of organisms or their components to make useful products
Dates back to ancient civilization
Using yeast to make beer and bread
Selective breeding of animals
DNA technology
Modern lab techniques to study and manipulate genetic material
Allows scientists to extract genes and transfer it to another organism
Later advanced by new methods for making Recombinant DNA
Recombinant DNA forms when scientist combine pieces of DNA from 2 different species
Today it is widely use for Genetic Engineering which is the direct manipulation of genes for practical purposes
Examples
Engineering bacteria to mass produce chemicals for drugs and pesticides
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Transfer genes from bacteria into plants and animals
How?
Use bacteria plasmids
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Method
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Enzymes are used to cut and paste DNA
Cutting tools are bacterial enzymes called restriction enzymes
Restriction enzymes bind to a restriction site and cuts both strands off DNA to make restriction fragments
Once cut, restriction fragments of DNA are pasted together by the enzyme DNA ligase
Nucleic acid probes are complementary molecules used to find a specific gene or other nucleotide sequence within a mass of DNA
Reverse transcriptase can help make genes for cloning
The chosen cells transcribe their genes within the nucleus and produce mRNA
Single stranded DNA transcripts are made from the mRNA using reverse transcriptase
Another enzyme is added to break down mRNA
DNA polymerase synthesizes a second DNA strand
Complementary DNA (cDNA)
New techniques allow a specific gene to be edited
CRISPR - Cas9 system
Big Idea 2: Genetically Modified Organisms
Even though there are advantages to using bacteria it is sometimes between to use a eukaryotic cell to produce a protein product
The first choice is often yeast
They are easy to grow and better at synthesizing and create eukaryotic proteins
Saccharomyces cerevisiae creates a number of proteins used in medicines
Hepatitis B
Antimalaria
Interferons used to treat cancer and viral infections
Hydrocodone
Mammals provide the cells of choice for making gene products
They secrete glycoproteins which have chains of sugar attached to them that allow them to make certain products
Tissue plasminogen factor (TPA) which is administered after heart attacks
Human erythropoietin (EPO) hormone stimulates the production of red blood cells
Antithrombin - prevents improper blood clotting : injected into a goat, harvested through their milk and turned into a drug to inject into patients
DNA technology has medical applications
Treating diseases
Insulin
Human growth hormone
Preventing diseases
Vaccine
Genetically Modified Organisms (GMO's)
Organisms that have acquired one or more genes by artificial genes
Vast majority of staple products are GMO's
Transgenic Organism
Improves food production, shelf life, pest resistance, and nutritional value
Concerns
Human Safety
Studies show little harm
Environmental safety
Labeling
Similar to how you can manipulate DNA and make GMO's you can manipulate it with other DNA to clone animals for our benefit.
Gene therapy
Replacing a defective gene
Methods
A gene from a healthy version is cloned, converted to an RNA version and then inserted into the RNA genome of a harmless virus
Bone marrow cells are taken from the patient and infected with the recombinant virus
The virus inserts a DNA version of its genome including the normal human gene into the cell's DNA
The engineered cells are then injected back into the patient, transcribe, translated and then produce the protein.
Big Idea 3: DNA profiling
Modern DNA technology has transformed the field of forensics
Figuring out suspects in a crime scene
Overview of a typical investigation involving a DNA profile
DNA samples are isolated from the crime scene, suspects, victims, or other evidence
Selected markers from each DNA sample are amplified to produce a large sample of DNA fragments
Amplified DNA markers are compared
The PCR method is used to amplify DNA sequences
The polymerase chain reaction (PCR) is a technique by which a specific segment of a DNA molecule can be targeted and quickly amplified in the lab
Uses primers
Gel electrophoresis sorts DNA molecules by size
Repetitive DNA
Short tandem Repeat (STR)
STR analysis
Big Idea 4: Genomics and Bioinformatics
Genomics is the study of complete sets of genes
Researchers have used tools and techniques of DNA technology to develop more and more detailed map of genomes of a number of species
Genomes vary in size and number of genes
Prokaryotes have smaller genomes
Eukaryotes have larger genomes
Chapter 1-9 Connection : - Flow of Information Genomes are the key our genetic identity.:
Human Genome Project
Uses the whole-genome shotgun
The need to collate and analyze the flood of sequence data pouring in from genome projects has led to the development of bioinformatics
The successes in the field of genomics have encouraged scientists to begin similar systematic studies of the full protein sets encoded by genomes an approach called proteomics.
Chapter 1-9 Connections - Interactions: Since proteins carry out most of the activities of cells, scientists must study when and where proteins are produced and how they interact to understand how organisms function.
Chapter 1-9 Connection - Evolution: Databases like GenBank allow researchers to compare genome sequences from many species and hypothesize about evolutionary relationships between those species to be tested.