What did Griffith discover? How?
Transformation- wanted to design vaccine to virulent (pneumonia) (s strain is harmful r strain is not) discovered heat killed bacteria transformed to harmless and made it harmful.
What did Avery discover? How?
DNA is the transforming agent. He used enzymes to isolate all possible agents of transmformation including protien, RNA, and DNA.
What did Hershey and Chase discover?
They wanted to know the hereditary molecule of viruses that infect bacteriophages. Used radioactive isotopes, discovered it was DNA.
What did Rosalind Franklin discover?
x-ray defraction work led to discvoery of double helix
What did Watson and Crick discover?
DNA double helix
What year was Watson and Crick's paper published?
What was Watson and Crick's paper about?
DNA made two chains wrapped in a helix, explains how replication works.
What elements are in DNA?
carbon, hydrogen, oxygen, nitrogen, and phosphorus
What are the three parts of a nucleotide?
5-C sugar, Phosphate group, and nitrogenous base
What are purines?
Dobule ringed structures, including adenine and guanine
What are pyrimidines?
single ringed structures including tyhmine cytosine and uracil
What are the complementary pairings?
- adenine-thymine (2H bonds)
- cytosine-guanine (3H bonds)
- adenine-uracil (2H Bonds)
What is DNA Repilcation?
process of copying NDA before any cell divison
What enzyme is responsible for DNA Replication?
Briefly Compare/Contrast RNA and DNA
- DNA RNA
- -Deoxyribose -Ribose
- -Double Stranded -Single Stranded
- -Stores info -Leaves nucleus
- -Thymine - Uracil
- -Makes proteins
What is transcription? What enzyme is responsible for it?
What is translation? (gene expression)
RNA to protein
What does mRNA do?
carries instructions from gene to make protein
What does tRNA do?
takes amino acids to ribosome to make proteins
What does rRNA do?
part of ribosomes where protein synthesis occurs
What is a codon? anticodon? amino acid?
- three nucleotide sequence in mRNA that encodes for an amino acid
- anti- complementary to codon
- amino- carboxyl, amino group= protein monomer
- *REMEMBER for amino chart use mRNA*
Why must there be a triplet DNA code?
three DNA latters needed to produce enough combinations for 20 amino acids
How are RNA moelcules edited before leaving nucleus in eukaryotes?
- post transcriptional editing- removes introns (junk DNA)
- adds a cap on the 5' end (CH3 group- methylated)
- adds a polyadeninated tail on the 3' end
What is a change in the genetice code? What is it caused by?
- mutation- caused by a change in the nucleotide sequence
- insertion/deletion(frameshift), substitution
What is the difference between a gene and chromosome mutation?
Gene mutation is a mistake in the DNA and is coded for, chromosome is physically missing.
Compare and contrast point mutation and frameshift.
- substition- won't code for the right protein
- frameshift- there will be extra parts of nucleotide sequence, and the end of the chain won't be right
What are the four types of chromosomal mutations?
Duplication, inversion, translocation(part breaks off and attatches somewhere else), deletion
What is an operon? What organism has them?
- gene that codes for specific products and regulatory elements for these genes
Describe a promoter.
DNA segment that initiates RNA transcription (recognized by RNA polymerase)
Describe an operator.
DNA segment that serves as a kind of switch that allows RNA Polymerase's access to promoter
Describe a repressor.
protein that inhibits a gene from being expressed
Describe an inducer.
Lactose binds to repressor protein- detatches from operator now free reign for RNA polymerase