Download on tRNA

Name:_________________________________________
DNA and Protein Synthesis Study Guide
Not all of this information has been covered in class YET!
1. What three small molecules make up a nucleotide?
Nitrogen base, phosphate group, and deoxyribose sugar
2. How do the nitrogen bases pair together in DNA?
Hydrogen bonds between complimentary nitrogen bases
3. In your own words, describe the differences between transcription and translation.
Transcription is copying DNA into mRNA and takes place inside the nucleus. It is the first step to
protein synthesis. Translation occurs outside the nucleus and is the final process of protein synthesis.
It involves taking the message from mRNA and building a protein from amino acids.
4. Below, explain the steps of DNA replication. Make sure to list the finished product of replication.
First, Helicase unzips the DNA. Then, Primase adds primers to each side. Lastly, DNA Polymerase adds
nucleotides to each side completing the new strand. Copying a DNA molecule into two molecules.
Each new molecule has one old strand and one new strand.
5. What is a gene? Where are genes located?
A gene is a section of hereditary material that codes for a specific trait. Because they are made from
DNA, they are found in the nucleus.
6. Compare and contrast mRNA, rRNA, and tRNA.
mRNA: copies DNA code and takes it to a ribosome
tRNA: carries an amino acid from the cytoplasm to the ribosome to be assembled into protein
rRNA: along with proteins, makes up the ribosome
7. Define transcription. Where does transcription occur? What is the final outcome of
transcription?
Transcription occurs in the nucleus. It’s when mRNA is made from DNA. The product is mRNA. The
prime enzyme is RNA Polymerase.
8. What are the different types of chromosomal mutations?
Deletion, Duplication, Inversion, and Translocation. Be sure that you can explain each one!
Name:_________________________________________
9. Explain how mutations, mutagens, and carcinogens are all related.
A mutation is a change in the DNA sequence that was not there originally. Mutagens are agents that
cause mutations to DNA. And carcinogens are agents that can cause cancer. So, mutagens can cause a
mutation that can lead to cancer. Therefore, a mutagen can also be a carcinogen.
10. What happens during translation?
Ribosome attaches to mRNA. tRNA brings amino acids that correspond to codons on mRNA. Ribosome
connects amino acids to make a protein.
11. Create the complimentary strand for the following DNA:
AGG TGC GAT TAC AGA
TCC
ACG CTA ATG TCT
12. Take the same DNA sequence from above and transcribe it into RNA:
UCC ACG CUA AUG UCU
13. What is an anticodon and how does it contribute to protein synthesis?
Set of complimentary three nucleotides to mRNA used to code for an amino acid on tRNA.
14. What is a point mutation? What are some examples of point mutations?
A mutation in one or only a few nucleotides. Point: silent, missense, nonsense, insertion, deletion.
NOTE: Missense-when the amino acid sequence gets mixed up because of a frameshift.
Nonsense- when there is a premature STOP.
15. What is a transposon and how are they significant?
Transposons can move from one part of the DNA to another. They can block or activate genes. They
are referred to as jumping genes.
16. What is the structure of DNA called?
Double Helix
17. What is the relationship between DNA, genes, and chromosomes?
Genes are found on chromosomes, made of DNA and DNA coils into chromosomes.
18. List some differences between DNA and RNA.
Name:_________________________________________
DNA: Can’t leave the nucleus, ATCG, deoxyribose sugar, double stranded, larger
RNA: Can leave the nucleus, AUCG, ribose sugar,single stranded, smaller
19. What are the nitrogen base pairs for RNA?
Cytosine, Guanine, Adenine, Uracil
20. What does structure III in the picture to the
right represent?
Amino acids
21. What are the building blocks of proteins?
Amino acids (20)
22. Explain the Central Dogma of Biology.
DNA is copied into mRNA which is used to make protein.
23. Why is DNA replication important for all living things/organisms?
DNA replication is important for cell division.