Biol 230 Midterm #2 Flashcards
Define: Aflatoxin
A family of carcinogen, poison, and mutagens, that are produced by certain molds.
Can create a DNA adduct on a guanine nucleotide that can lead to cancer due to a loss of function is p53 (tumor suppressor gene).
Explain: DNA Replication
The first step of the central dogma.
Helices unzips the DNA strands.
The DNA polymerase enzyme travels along the DNA strand, creating a complementary strand from the 5’ to the 3’ end.
Both strands serve as template for the complementary strands to replicate from.
The leading strand (towards the fork) and lagging strand (away from the fork) are replicated differently.
Define: DNA polymerase
DNA polymerase (DNAP) is a type of enzyme that is responsible for forming new copies of DNA, in the form of nucleic acid molecules.
Reads DNA from the 3’ to 5’ ends.
Synthesizes DNA from the 5’ to 3’ ends.
Define: p53
Tumor suppressor gene.
It can activate DNA repair proteins when DNA has sustained damage
It can arrest growth by holding the cell cycle at the G1/S regulation point on DNA damage recognition. (Slows cell growth)
It can initiate apoptosis (i.e., programmed cell death) if DNA damage proves to be irreparable.
It is essential for the senescence response to short telomeres.
Many cancers are a result of a mutation in this gene.
Define: Translation
The process of translating the sequence of a messenger RNA (mRNA) molecule to a sequence of amino acids.
Define: Acquired mutation
A mutation that has been acquired during the lifetime of the organism.
Not inherited.
Define: Colon cancer
Unregulated growth of cells that begins in a part of the large intestine called the colon.
Define: Polyp
A small growth, usually benign and with a stalk, protruding from a mucous membrane.
Define: APC gene
Tumor suppressor gene.
Define: Inherited mutation
A mutation that has been inherited, from ‘parent’ to ‘offspring’.
Mutations like these must be acquired in the gametes, in order to be passed down through generations.
Not acquired.
Explain: Cell cycle
Mitosis, Cytokinesis, Interphase (G1, S, G2. (G0)).
Explain: Transcription
Transcription is the process of copying a segment of DNA to synthesize RNA.
Define: DNA Adduct
A DNA nucleotide covalently bonded to a chemical. (safrole, benzopyrenediol epoxide, acetaldehyde).
Define: Sister-chromatids
The two identical chromatids that are formed by replication of a chromosome during the S phase of the cell
Deine: Homologous Pairs
A pair of matching chromosomes in an organism, with one being inherited from each parent.
Explain: S phase of cell cycle
When DNA replication occurs.
S for sister.
Explain: M phase of cell cycle
The phase where division occurs, containing mitosis and cytokinesis.
Explain: Mitosis
The process by which a somatic cell is duplicated. (Copy machine)
‘Produces’ two similar diploid cells.
PPMAT
Define: Diploid
Containing two complete sets of chromosomes, one from each parent.
Explain: Meiosis
The process by which germ line cells are produced. (Slot machine)
‘Produces’ four randomized haploid cells.
Crossing over.
Random Assortment.
Meiosis I and Meiosis II.
Explain: Law of segregation
Alleles segregate randomly into gametes.
Explain: Copy machine
Mitosis is considered the copy machine, because it’s ‘goal’ is to create exact copies.
Define: Haploid
Having a single set of unpaired chromosomes.
Define: Gametes
A mature haploid male or female germ cell which is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
Explain: Slot machine
Meiosis is referred to as the slot machine, because its ‘goal’ is to combine genetic information in a random fashion to create genetic variation. The outcome of which could be looked at as a slot machine.