Unit 4 Flashcards
What are the differences between DNA and RNA
DNA
double helix
5c sugar- deoxyribose
Base: adenine, Guanine, Cytosine, Thymine
RNA
Single Helix
5c sugar- ribose
bases: adenine, guanine, cytosine, uracil
What is the structure of DNA molecule called?
Deoxyribonucleic acid
What is the structure of RNA molecule called?
ribonucleic acid
What did johann Miescher contribute to the knowledge of DNA?
discovered in 1868 in pus from war bandages and in fish sperm. called it “nuclein”
What did Robert Fuelgen contribute to the knowledge of DNA?
1914 devloped a stain for nuclein; stains chromatin red
What did Fredrick Griffith contribute to the knowledge of DNA?
1928 worked with streptococcus pneumonia bacteria. Hypothesized that DNA was pathogenic- disease cause
What did Oswald Avery contribute to the knowledge of DNA?
1944 used enzymes to destroy proteins and then DNA in bacteria.
Concluded that hereditary material was probably made of DNA and not protein
What did Alfred Hershey and Martha Chase contribute to the knowledge of DNA?
Confirmed Avery conclusion. Proved that the genes were made of DNA, not protein
What did Erwin Chargaff contribute to the knowledge of DNA?
1949 worked on DNA composition in USA
Concluded that a always equaled t and g= c
Also concluded that different species had different numbers of nucleotides, because they have different amounts of DNA nucleotide
What did Maurice Wilkins and Rosalind Franklin contribute to the knowledge of DNA?
Both worked on the DNA structure
Franklin made the best x-ray diffraction of crystalline DNA, and worked out the dimensions of the molecule
What did Watson and Crick contribute to the knowledge of DNA?
Bulit model of DNA in 1953
Used info of Franklin
What was the purpose of project genome?
Decoding human DNA
What contributions did center and collins make to project genome?
Used computers to speed gene sequencing
What are the monomers of nucleic acids called?
Nucleotides
Which subunits are the same in the nucleotides? Different?
3 subunits, the phosphate group and pentose sugar are same while nitrogen bases will be different
What are the 2 purines? Describe them
Large, 2 carbon rings
Guanine
Adenine
What are the 2 pyrimidines? Describe them
Small, 1 carbon ring
Cytosine
Thymine
What scientist discovered the first enzyme associated with DNA Replication?
Arther kornberg, DNA Polymerase l
What scientists proved that DNA replication was semi conservative?
Matthew meselson and Franklin stahl
What does semi conservative replication mean?
Semiconservatie- one strand of DNA is made is made of original nucleotides and the complimentary strand of DNA is made of new nucleotides
What is the function of helicase associated with DNA replication
Unwinds the double helix, creating a fork
What is the function of polymerase lll associated with DNA replication
Add nucleotides to the leading strand- 5’3’ continuously
What is the function of DNA polymerase l associated with DNA replication
Adds nucleotides in short sections called Okazaki fragments
What is the function of ligase associated with DNA replication
Puts fragments together
What is the function of “proof reading” enzymes associated with DNA replication
Proofing reading the nucleotides. 1 mistake/ 100,000,000 nucleotides
What are the Okazaki fragments
The new DNA Strand forms in short fragments
Which strand is the “leading” strand and is replicated continuously in DNA
5,3
Which strand is the “lagging” strand and is replicated in fragments
3,5
When does DNA replication occur
Occurs in interphase, just before prophase in mitosis
What are mutations
A mistake that survives as a mutation. It usually changes gene. Can cause disease, improvement, or evolution
What are the most common causes of mutations
Mutations can be produced by exposure to radiation, chemicals, and heat
The theory of Enosymbiosis suggests that mitochondria and chlochloroplasts once lived lives as independent organisms. What do these organelles possess that makes them different from other organelles?
The ability to replicate
What are most genes the formulas for
Proteins
What are the general functions of proteins
Used to construct body tissue, enzymes, hormones, antibodies, and are a source of ATP
What are the monomers of proteins
Amino acids
How many amino acids are used by most organisms to build proteins
20
What base is substituted for thymine in RNA
Uracil
What type of rna is a complete copy or transcript of the DNA gene
MRNA
What type of RNA carries amino acids from the cytoplasmic pool to the ribosome
tRNA
What type of RNA combines with proteins to form the subunits of the ribosome
rRNA
What type of RNA is built of codons
mRNA
What are the 3 nucleotides in tRNA called
Anticodons
How many different tRNA are made? Why?
20, one for each amino acid
Which phase of protein synthesis occurs firsts?
Transcription
Where does the first phase of protein synthesis occur
Occurs in nucleus
Which strand of DNA is transcribed?
3’5’ strand
What enzyme catalyzes transcription?
RNA Polymerase
How does the enzyme in #16 know when to start and stop coding the gene?
With a start code and stop code
What is the first transcript called?
Primary transcript
What forms 2/3 of the primary transcript
Introns
What are the functional parts of the transcript called
Extrons
What are the non-functional parts of the transcript called?
Introns
What removes the introns of the primary transcript
SnRPS - small Nuclear Ribonucleoprotein particles
What is the “snRNP’d” mRNP called?
Functional or Mature RNA
Where does the second phase of protein synthesis occur
Translation
What is the second phase of protein synthesis called
Translation
What are the sites in the ribosome called where peptide bonds are formed between amino acids
Accepter site and peptidal site
What are polysomes
Many ribosome that attach to the mRNA and each translates the same strand of mRNA.
Which occurs more often, protein synthesis or DNA replication
Protein synthesis
What is the poison ricin extracted from and what is its effect?
Castor bean plant that removes an adenine base from rRNA in the large of the ribosome and shuts down protein synthesis
What is the function of primase associated with DNA replication
Synthesize a short RNA Primer on the lagging strand 3’5’
