Lecture 1 - 9 Terms Flashcards
What is a virus?
small pieces of nucleic acid. Can be DNA or RNA
What is a prion?
Misfolded proteins that can infect cells (a type of virus)
What is a viriod?
a bare piece of RNA that causes diseases in plants.
What is a genome?
An organisms complete set of DNA.
What is a transcriptome?
An organisms complete set of mRNA.
Genomics
the study of sequencing/assembling/analyzing genomes.
metagenomics
collecting environmental samples of earth and sequencing the bits of DNA/RNA found in soil.
Define a macromolecule.
a molecule with over 1,000 atoms. Often polymers.
Define small molecules
less than 1,000 atoms. often are monomers.
give examples of polymers.
starch, glycogen, cellulose, DNA/RNA, proteins, phospholipids.
give examples of monomers
monosaccharides (glucose, fructose, galactose), nucleotides, amino acids, ATP/ADP, GTP,GDP
What are chromosomes.
pieces of DNA and proteins linked to each other.
Define the term ploidy.
the number of sets of chromosomes in a cell. most animals are diploid, gametes are haploid.
what is a dyad?
a pair of sister chromatids. they will be separated during mitosis.
what is recombination?
when two sister chromatids swap genetic material while lined up on the metaphase plate. occurs during. Prophase I
what is aneuploidy?
an abnormal number of chromosomes.
what is trisomy?
one extra chromosome
What is monosomy?
a missing chromosome
Define translocations.
a DNA segment that is moved from one chromosome to a different chromosome (not a homologue)
what is an inversion?
a segment of DNA that is flipped. it will be coding backwards.
what is a deletion?
a segment of DNA is cut out of the DNA.
what is an insertion?
a segment of DNA is inserted into a different area on the same chromosome.
what is a centromere?
the middle of the chromosome. contains constitutive DNA (heterochromatin).
what is constitutive DNA?
Constitutive heterochromatin is the stable form of heterochromatin, i.e. it does not loosen up to form euchromatin, and contains repeated sequences of DNA called satellite DNA. It can be found in centromeres and telomeres, and is usually involved in structural functions.
define kinteochores.
a large protein complex that is encoded by the DNA within the centromere. It is where the microtubules will attach during metaphase.
what are telomeres?
a non-coding region at the end of some chromosomes. short repeated sequence of TTAGGGTTAGGG.
What is cellular senescence?
when a cell can no longer divide because it’s telomeres are too short. The cell will undergo apoptosis.
what is telomerase?
an enzyme with an RNA template that adds nucleotides to the 3’ end of the DNA template.
What is reverse transcription?
when DNA is synthesized from RNA.
What are cancer stem cells?
an adult stem cell that has mutated. Thus it bypasses regulatory factors controlling cell division.
What is alpha-satellite DNA?
found at the centromere. they encode the proteins that will form the kinetochore complex (where microtubules will bind to)
what are pseudo-genes?
genes that have become functionally inactive over periods of evolution.
define repeat elements.
repeating DNA segments that do not appear to serve a purpose (not used by the cell).
give an example of repeat elements.
Transposons/Transposible elements, microsatellite DNA
What are transposons?
they are DNA that can copy themselves and “jump” into other non-homologous chromosomes.
What is microsatellite DNA?
1-60 repeats that occur in succession 4-6 times. they vary across individuals, therefore they are used in forensics and paternity tests to find DNA matches. (Use PCR)
What are chromatin fibers?
coiled and condensed DNA that forms chromosomes. made of proteins (histones) and DNA.
What is euchromatin?
a state of DNA, where it is accessible for transcription.
What is heterochromatin?
a state of DNA, does not allow transcription to occur.
What is faculative heterchromatin?
DNA that can be condensed and uncondensed when needed.