DNA Tes
Structure of tRNA
Bottom there is anti-codon (bases) and at the top there is an amino acid that correlates with the codon
How does DNA control a cell?
By coding for the order of amino acids that make up protein molecules
7. Give three differences between DNA and RNA?
DNA: Double stranded, has deoxyribose sugar, contains the base thymine RNA: single stranded, has ribose sugar, contains the base uracil
What happens in transcription
First the RNA polymerase "unzips" the two DNA strands. One strand isn't used (called the dummy strand) because it's mute. The other strand is called the active strand and that is the one used to make the mRNA. The mRNA is an RNA copy of the active strand and contains instructions to make proteins. The RNA polymerase creates a base on the mRNA that is complementary to the base on the DNA. It moves down the strand and creates the mRNA bases one at a time. This occurs in the nucleus (the bases are floating around in the nucleus waiting to be used). The mRNA is terminated from the DNA and the DNA goes back to normal. The mRNA is fixed up by proteins. It then leaves the nucleus.
8. List all the complimentary base pairs in DNA and RNA.
In DNA and RNA: guanine and cytosine In DNA: Adenine and thymine In RNA: Adenine and uracil
What is a codon
It is a sequence of 3 bases that forms a unit of a gene on RNA and DNA found on the mRNA.
6. What is mRNA? What is the function of mRNA?
It is messenger RNA and is an RNA copy of an active strand of DNA. It codes for an amino acid sequence that creates a protein. The function is to copy the DNA code so the mRNA can carry the code into the cytoplasm where the ribosome is.
What is the anticodon
It is the sequence of three bases that are complementary to the bases on the codon. It is found on tRNA.
1. What are the subunits of a DNA molecule?
Nucleotides
List the location of transcription and all the molecules involved
Nucleus with mRNA, RNA polymerase, DNA
2. What are the three components of the subunit?
Phosphate, sugar, and bases (thymine, adenine, guanine, and cytosine)
List the location of translation and all the molecules involved
Ribosome/cytoplasm with mRNA, tRNA, amino acids, and proteins.
3. What is found on the sides of a DNA molecule?
Sugar and phosphate
What is transcription
The first part of protein synthesis where the DNA is rewritten into mRNA. DNA is used by RNA polymerase to make mRNA.
What happens in translation
The mRNA enters the cytoplasm and finds a ribosome. Once it becomes associated with the ribosome it can begin coding. Transfer RNA are small molecules that contain specific amino acids. The mRNA is made up of codons which are a special sequence of three nitrogen bases. The tRNA contains the anti-codon which are the bases complementary to a specific codon. The tRNA binds to the mRNA codon. When the next tRNA comes the previous tRNA will leave its amino acid with it. Eventually the tRNA will reach the stop codon and the last amino acid will be attached in the chain. The chain of amino acids form a protein.
What is translation?
The second part of protein synthesis where the mRNA is "decoded" and is used to create a specific chain of amino acids (a protein). tRNA uses mRNA to line up amino acids.
Why do proteins differ from one another?
The sequence of amino acids is different
What is tRNA and what's its function
Transfer RNA are small molecules that have a specific amino acid and bind to the mRNA to help it code for a protein. It binds with the mRNA and creates the chain of amino acids, forming the protein.
What is a frameshift mutation?
When you add or delete a base, causing the whole frame of the gene to shift. It changes the whole gene after it.
What is a point mutation?
When you change/swap a base in a gene code. Change occurs in one base it is a type of gene mutation.
5. What is the shape of DNA called?
double helix
What is a chromosomal mutation
mutations that produce changes in whole chromosomes
17. In a DNA molecule what is the base bonded to the sugar or the phosphate?
sugar
What determines the amino acids in a protein
the order of bases in DNA
What is DNA replication
the process of copying DNA for cell division, EXACT copy is formed
DNA to mRNA
transcription
mRNA to protein
translation
Proteins make up structures
type of protein is enzyme
Why is DNA replication semi-conservative?
~ Because one strand is from the original DNA and one strand is new
What are the steps of DNA replication
1. The DNA double helix "unzips" which is done when an enzyme called helicase breaks the hydrogen bonds holding the complementary bases together 2. The separation of the strands forms a Y shape and both strands act as templates for the new DNA 3. An DNA polymerase will create the complementary bases for both strands. This is how the DNA is identical. 4. It will result in two DNA molecules made of one new and one old chain of nucleotides.
What is mutation
A change in the DNA
what is a mutagen
An agent that can cause genetic mutation: radiation (x-rays, tanning booths), chemicals (cigarette smoke, pollutants), viruses (HPV)