DNA Replication
This enzyme is responsible for breaking hydrogen bonds between nucleotides during DNA replication.
Helicase
Transcription occurs in the _____________________. Translation occurs a the ___________________.
Nucleus
Ribosome
The ______________ is the RNA polymerase binding site.
Promoter
Was is the monomer of DNA?
nucleotide
Differentiate between DNA and RNA.
double stranded, deoxyribose sugar, (A, T, C, and G)
RNA:
single stranded, ribose sugar, (A, U, C, and G)
Describe the term "semi-conservative replication".
Semi-conservative replication means that when two new DNA molecules are created, half of each new molecule is "old", from the original strand, and the other half is newly synthesized DNA.
Describe the structure of a tRNA molecule.
tRNA carries an amino acid on one end and has an anti-codon on the other end.
This type of operon is usually turned on. The repressor is not normally attached.
Repressible Operon
What are the three parts of a nucleotide?
Sugar, Phosphate, Nitrogen Base
The kind of bond that attaches amino acids together is called:
peptide bond
At what point during the cell cycle does DNA replication happen?
During INTERPHASE (the s-phase) before mitosis/meiosis.
Describe the process of alternative splicing in mRNA.
Alternative splicing is used to take introns OUT and bond exons together to create a mature mRNA molecule.
This type of operon is inactive (off) in its default state, meaning the regulatory protein is normally attached to the operator.
Inducible Operon
What do you know about the directionality of a DNA molecule?
The ribosome starts protein synthesis at a specific codon. Name the codon and which amino acid it codes for.
AUG-methionine
DNA polymerase III isn't always perfect and sometimes makes mistakes when inserting DNA nucleotides. What is the name of the enzyme that "fixes" these mistakes?
Exonuclease
Describe two kinds of post-transcriptional modification that occurs in the primary transcript before translation occurs.
Addition of a poly-A tail on the 3' end of mRNA and addition of a GTP cap on the 5' end of mRNA.
The LAC operon is an example of a(n) _____________ operon and the TRP operon is an example of a(n) ______________ operon.
inducible
repressible
Which of DNA's nitrogenous bases are purines and which are pyrimidines?
Purines: Adenine and Guanine
Pyrimidines: Thymine and Cytosine
Name the three steps of translation.
1. initiation
2. elongation
3. termination
Use the words "leading strand", "lagging strand", "DNA polymerase III", "okazaki fragments", and "ligase" to briefly describe the process of DNA replication.
During DNA replication, the leading strand is built by DNA polymerase III continuously toward the replication fork in the 5' to 3' direction. As the DNA is unzipped, several okazaki fragments are created by DNA polymerase III in the 5' to 3' direction away from the replication fork. These fragments are "glued together" by ligase, creating the lagging strand.
Using the words, "nucleus", "mRNA", "transcription", "ribosome", "codon", "anti-codon", "tRNA", "amino acid", and "translation", briefly describe the process of protein synthesis.
During transcription, mRNA is created in the nucleus. After modification, it travels to the ribosome and translation occurs. tRNA carries amino acids to the ribosome where base pairing rules are used to pair the tRNA anti-codon to the mRNA codon. The amino acids are bound together by peptide bonds and a protein is created.
The ___________ is made by a regulatory gene and it blocks transcription.
repressor
1. This type of bond holds the nucleotides together.
2. This type of bond holds the sugar phosphate backbone of DNA together.
1. hydrogen bond
2. phosphodiester
What is the "central dogma" of biology?
This is a theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein.