Biology Midterm (DNA Replication and Protein Synthesis) Only
What is the normal ratio of cell division to cell death
1
How do cells deal with copying mistakes during replication
1. Apoptosis 2. DNA repair
We know that DNa replication mistakes can cause mutations in cancer genes, what other things are also known to cause these mutations
1. Radiation 2. Chemicals 3. Bacteria 4. Viruses
Protein synthesis rates in prokaryotes are limited by the rate of mRNA synthesis. If RNA synthesis occurs at the rate of 50 nucleotides/sec, then rate of protein syntheisis occurs at
17 amino acids/sec
Proteins contain ____________ different amino acids, wheras DNA and RNA are composed of ____________ different nucleotides
20, 4
The DNA code for an amino acid consists of a sequence of
3 nitrogen bases taken from 4 possible bases
What is the direction of DNA synthesis
5 to 3
The growing polypeptide chain is released from the ribosomes when
A chain terminating codon is reached
In the semiconservative replication of DNA, progeny DNA molecules consist of
All molecules with one parental and one new strand
List one thing that happens if apoptosis is not happening normally
Autoimmune disease, tumor, cancer
Which of the following is not a necessary component of translation? A. Anticodon B. mRNA C. Ligase D. Amino Acid
C
Amino acids are joined together into a protein chain by which of the following? A. tRNA B. DNA polymerase C. Hydrogen bonds D. mRNA
D
Which is required for protein synthesis a. tRNA b. mRNA c. rRNA D. All of these
D
Which of the following is not necessary for protein synthesis to occur, once transcription is completed?
DNA
The enzyme which copies DNA
DNA polymerase
What benefit do organisms get out of not having a perfect DNA replication system
Evolution
Coding regions of DNA are termed
Exons
Diagram the cell cycle and show which phase DNA is replicated
G1 -> S -> G2 -> M S phase
Seperation of molecules according to size can be achieved by what
Gel filtration chromotography
The enzyme which unwinds DNA and breaks hydrogen bonds during replication
Heliacase
Noncoding regions of DNA are termed
Introns
what scientist discovered DNA polymerase?
Kornberg
The enzyme which seals the fragments of the lagging strand?
Ligase
What scientist cracked the genetic code and determined the table of codons
Marshall Nirenberg
What two scientists determined that DNA replication was semiconservative
Meselson and Stahl
Which of the following amino acid starts all protein synthesis A. Glycine B. Proline C. Thymine D. Methionine
Methionine
What organelle is the site of transcription
Nucleus
The name of the newly synthesized fragements on the lagging strand?
Okazaki fragments
What enzyme is involved in transcription?
RNA polymerase
Exons of a gene are defined as
Regions that remain in the corresponding mRNA after splicing
The site for production of most proteins within a cell is the
Ribosome
Where does translation take place?
Ribosome
The copying process of DNA is known as
Semi Conservative DNA Replication
If a mutation occurs in a segment of a DNA molecule, it is reasonable to conclude that
The complementary RNA would also be altered
List one normal use of apoptosis in our body
To shape organs
Which site of the tRNA molecule binds to the mRNA molecule?
anticodon
The two polynucleotide chains in DNA are
antiparallel
The anticodon of tRNA
binds to an mRNA codon
For what type of product does an intron code?
no functional product
The amino acid sequence of proteins is determined by
nucleic acids
In a cell, the transfer of genetic information from DNA to RNA occurs in the
nucleus
Genes act by directing the synthesis of
proteins
The ribosomes are composed of
proteins and RNA
A codon is a sequence of mRNA that has gone through which process?
splicing
the addition of -amanitin, a known inhibitor of DNA-dependent mRNA synthesis, to growing cells will most likely cause protein synthesis to:
stop as mRNA becomes depleted
The molecules which carry amino acids to the ribosomes are
tRNA
Which of the following RNAs bind to an amino acid
tRNA
How many bases of nucleic acid determine a single amino acid?
three
what forms if cell division outpaces cell death?
tumor