Normal Flow: DNA, RNA, Protein Retrovirus: RNA, DNA, RNA, Protein Virus Function Virus: small nucleic acid genome enclosed in capsid Penetrates cell → takes over metabolic machinery → assembles new virus copies Virus Structure Nucleic Acid: either RNA or DNA which...
A change in the sequence of nucleotides in an original DNA molecule Mutations are irreversible and the main cause of genetic variation (alleles) Mutations can cause changes in phenotype (ex. cystic fibrosis) or disorders Alterations in DNA can lead to changes in type...
Improvements in the identification and treatment of disease. But some benefits can be abused. Social and ethical questions include… Pharmaceuticals: DNA cloning allows quick and inexpensive production of pharmaceuticals Ex: human insulin and human growth hormone (HGH)...
Gel Electrophoresis: a procedure that separates restriction fragments DNA fragments of diff lengths are separated as they diffuse thru a gelatinous material under influence of an electrical field DNA has same charge per...
PCR: a technique that makes large number of DNA copies faster than DNA cloning process DNA is heated. Heating denatures (separates) hydrogen bonding holding the dsDNA together and forms two ssDNA molecules DNA is cooled and ssDNA primers are added. Two primers are...
Procedure that allows DNA fragments or genes to be copied Use a restriction enzyme to cut up the foreign DNA that contains a gene to be copied. The restriction enzyme produces multiple fragments of foreign DNA with sticky ends Use the same restriction enzyme to cut up...
Making Multiple Copies of a Gene or DNA Segment Recombinant DNA: contains DNA segments or genes from diff sources One part of DNA molecule, chromosome or organism to another Transfer of DNA segments can happen naturally thru viral transduction, bacterial conjugation,...
Stem Cells: unspecialized cells during early stage of embryonic development that can reproduce indefinitely and differentiate (become any) into specialized cells But as development continues → cells differentiate & become specialized → cell divisions make more...
Specific genes expressed in cell during development determine cell type Cell can receive external and internal cues that cause regulation of gene expression by turning genes on/off External: cells receive signals from extracellular environment Adjacent cells: ex:...
DNA Methylation: Histone Acetylation Homeotic Genes: master genes that control the pattern of body formation during early embryonic development Ex: in flies genes control formation of body structures like body segments and antenna Mutant homeotic genes produce body...
Bacteria Coordinately controlled genes clustered in operon regulated by one promoter Prokaryotic regulation mostly at transcriptional level Prokaryotes don’t have RNA splicing or chromatin modification Operon “Unit of DNA that contains functionally related genes that...
Translation is where RNA is turned into proteins for the cell to use. In Eukaryotes, after transcription & processing mRNA, tRNA, and ribosomal subunits are transported across the nuclear envelope and into the cytoplasm In cytoplasm, a specific amino acid attaches...
In Eukaryotes, mRNA transcript must be processed before can exit the nucleus and be used for translation → Pre-mRNA longer than post mRNA 5’ Cap: is added to the 5’ end of mRNA ...
Transcription is where DNA strands are turned into RNA strands for translation to use. Initiation: RNA polymerase recognizes & attaches to a promoter sequence on the DNA and begins to unzip them into two strands Promoter Sequence: DNA sequence which starts...
Replication Proteins Lagging Strand Leading Strand
Helicase unwinds the parental double helix at the origin of replication→ forms a Y-shaped replication fork Origin of replication: short, stretch of DNA with a specific sequence of nucleotides Single-stranded binding protein attaches to each strand of uncoiled DNA to...
DNA Polymerase I vs. III Both can only add DNA to 3 end Polymerase I Responsible for removing RNA primers on replacing with DNA nucleotides Polymerase III Uses parental DNA to add DNA nucleotides 3’ end of RNA primers or existing strand...
Before duplication, hydrogen bonds between bases are broken → double strands unwind and separate into single strands → each strand serves as a template for new, complementary strand → replicated DNA consists of a single strand of old DNA (template strand) and a single...
Helicase Unwinds parental double helix at replication forks Single-stranded binding protein Binds to, stabilizes, and prevents single-stranded DNA from rejoining until is is used as a template Topoisomerase Binds ahead of replication forks & relieves overwinding...