Biology DNA & RNA study guide
What enzyme proofreads the results of replication to prevent mistakes?
DNA polymerase.
What enzymes are used in DNA replication?
DNA polymerase.
DNA is copied during a process called ___.
DNA replication.
What was already known when Watson and Crick tried to build a 3-D model of DNA?
DNA was composed of Thymine, Adenine, Cytosine, and Guanine.
Compare and contrast DNA and RNA.
DNA: deoxyribose sugar, ATCG, has Thymine, double stranded RNA: Ribose, AUCG, has Uracil, single stranded Alike: nucleotides, ACG, phosphates, covalent bonding
What are the different types of chromosomal mutations?
Deletion, duplication, inversion, translocation
What is point mutation?
When one base is substituted for another
What forms the "backbone" of DNA?
sugar and phosphate bonds.
The leading strand ____, while the lagging strand ___.
-Is replicated on the 5' to 3' direction... is replicated on the 3' to 5' direction. -Is replicated in one continuous strand... is replicated in small chunks. -Needs one RNA primer... needs many RNA primers.
How many hydrogen bonds does Adenine and thymine hold?
2 hydrogen bonds
How many hydrogen bonds does Cytosine and Guanine hold?
3 hydrogen bonds
What direction do you add bases on the DNA strand?
5' to 3'.
DNA replication must happen before _________.
A cell can divide.
How does frameshift mutation affect the final protein?
A change in amino acid sequence which changes the protein
According to the genetic code, the mRNA codons UCU, UCC, UCA, and UCG all code for the amino acid serine. What does this fact tell you?
A mutation in one base will always have a physical effect on the resulting protein.
According to Chargaff's rule, which of the following exists in DNA? A. C=G B. C>T C. C<G D. C=T
A. C=G
In eukaryotes, DNA... A. is located in the nucleus B. floats freely in the cytoplasm C. is located in the ribosomes D. is circular
A. is located in the nucleus.
The first mRNA codon to specify an amino acid is always ___.
AUG
What are the Purines?
Adenine and Guanine
What are the 4 nitrogenous bases?
Adenine, Guanine, Cytosine, Thymine
What bases are used in DNA replication?
Adenine, Guanine, Cytosine, Thymine
What bases are used in RNA synthesis?
Adenine, Guanine, Cytosine, Uracil
Transfer RNA's bind during translation by the ___.
Anticodon
DNA is made up of a phosphate group, an organic base, and... A. a protein B. a sugar C. a lipid D. a molecule of ATP
B. a sugar
Where does DNA replication take place in the cell?
Cell nucleus.
What are mutations?
Changes in genetic code that can occur in DNA replication
What type of bond holds nucleotides together?
Covalent bond
What are the parts of DNA?
Covalent bond, Guanine, Thymine, Adenine, Cytosine, hydrogen bonds, phosphate, deoxyribose
What forces hold together the two strands of DNA?
Covalent bonds.
What are the Pyrimidines?
Cytosine and Thymine
What are the effects of mutations?
Either beneficial, no effect, or disrupt gene function
What is the end result of transcription?
Forms proteins or mRNA.
If a base is deleted or inserted during DNA replication this is called a ___ mutation and results in ___.
Frameshift... a completely different protein.
During DNA replication, a DNA strand that has the bases CTAGGT produces a strand with the bases ______.
GATCCA.
What are the 2 different types of mutations?
Gene mutations and chromosomal mutations.
What enzyme unzips DNA for replication?
Helicase.
What bond holds the bases together?
Hydrogen bonds
What forces hold together the DNA backbone or nucleotides?
Hydrogen bonds.
How do mutations occur?
Inheritance or environment
What are chromosomal mutations?
Involves the change in the number or structure of a chromosome
How did Watson and Crick contribute to the structure of the DNA?
James Watson and Francis Crick built a 3-D model of DNA that explained the specific structure and properties od DNA. They got help for Franklins x-ray images.
What is the end result of DNA replication?
More cells are made.
How does point mutation affect the final protein?
Normal, incomplete, or faulty protein
What is the structure of a DNA molecule?
Nucleotides are arranged like a spiral staircase.
What is frameshift mutation?
One base is inserted or removed from DNA sequence
Where does RNA synthesis (transcription) take place?
The nucleus.
Where does transcription occur?
The nucleus.
What are the two types of GENE mutation?
Point and Frameshift
What enzymes are used in transcription?
RNA polymerase.
What does DNA do?
Responsible for storing genetic information
How did Rosalind Franklin contribute to the structure of DNA?
She used X-ray diffraction to take pictures of DNA strands. She found an x shaped pattern that shows the strands in DNA twisted around each other. This shape is known as a helix. Telling us there were 2 strands in DNA.
Write the complementary strand for 5' A T C C G A G C T T A G 3'
TAGGCTCGAATC
What did Erwin Chargaff find?
That the % Adenine= %Thymine and %Guanine=% Cytosine
What is antiparallel?
The DNA strands run in opposite directions.
Where does translation occur?
The cytoplasm.
What does the Double Helix model tell us about DNA?
The double helix model shows two strands of DNA that twist around each other like a twisted ladder.
Most mutations involve a misplacement of a nucleotide on a DNA segment. What is not a possible result of a mutation?
The gene that contains the mutation will be expressed in the same way as before the mutation.
Describe the process of gene expression.
The information in DNA is transcribed to RNA and then translated to make specific proteins.
What is base pairing?
The perfect fit of hydrogen bonds between A-T and C-G.
According to the genetic code, the mRNA codons UGU and UGC code for the amino acid cysteine, the mRNA codon UGA is a stop codon, and the mRNA codon UGG codes for the amino acid tryptophan. What would a mutation in the second base of the codon UGA likely mean for the resulting protein?
The resulting protein would most likely be unusually long.
Where is the "genetic key" of the DNA?
The rungs of the DNA ladder.
What is DNA?
deoxyribose nucleic acid
What are nucleotides made of?
deoxyribose sugar, phosphate group, a nitrogenous base
What is DNA's monomer?
nucleotides
What type of editing occurs in transcription?
pre-mRNA/ introns and exons
