A1.2 HL only Flashcards
Leading strand
the strand of nascent DNA which is synthesized in the same direction as the growing replication fork
replication fork
the area where the replication of DNA will actually take place
Lagging strand
one of two strands of DNA found at the replication fork, or junction, in the double helix
template strand
the strand that is used during transcription to produce RNA
coding strand
the DNA strand whose base sequence is identical to the base sequence of the RNA transcript
ribosome
an intercellular structure made of both RNA and protein, and it is the site of protein synthesis in the cell
DNA polymerase II
enzyme in DNA replication that checks for mistakes and repairs them
euchromatin
the less tightly coiled DNA that allows transcription factors and chromatin remodelers access, enabling transcription to occur
Nucleosome
a section of DNA that is wrapped around a core of proteins
heterochromatin
the highly coiled DNA that is no longer used in protein synthesis
Supercoil
a highly wound, wrapped, and condensed DNA strand
Chromosome
made up of proteins and DNA organized into genes
cell division
cell cycle in which the cell grows and replicates its chromosome(s) beforedividing
histones
a protein that provides structural support for a chromosome
octamer
The complex of eight histone proteins
H1 histone protein
plays a dominant role in establishing the compaction state of an array ofnucleosomesas well as influencing the conformation
transcription factors
a proteinthat controls the rate of transcription of genetic information from DNA to messenger RNA
prophase
the first phase of mitosis where chromosomes form
Naked DNA
DNA that is not associated with proteins, lipids, or any other molecule to help protect it
Thomas Morgan
biologist who discovered the inheritance pattern of genes located near each other on similar choromosomes
Oswald Avery
biologist who discovered genes are made of DNA and its role in development
Alfred Hershey
biologist who confirmed that DNA is the principle molecule in heredity
Martha Chase
biologist who confirmed that DNA is the principle molecule in heredity
bacteriophages
viruses that infect and replicate only in bacterial cells
viral DNA
DNA viruses have DNA genomes that are replicated by either host or virally encoded DNA polymerases
protein capsule
the protective structure surrounding viruses
Radioactive isotopes
An unstable form of a chemical element that releases radiation as it breaks down and becomes more stable
isotope 32P
A radioactive form of the element phosphorus. It is used in the laboratory to label DNA and proteins.
isotope 35S
the most stable radioactive isotope of sulfur, used in biochemical research to radioactively label proteins
pellet
The sedimented portion that accumulates during centrifugation
supernatant
The soluble liquid reaction of a sample after centrifugation
X-ray crystallography
a scientific field concerned with revealing the structure of matter at the atomic level. The essential method involves exposing a crystallised sample of a molecule to x-rays, usually with an instrument called an x-ray camera
Erwin Chargaff
biologiest who discovered that in the DNA of any species and any organism, the amount of guanine should be equal to the amount of cytosine and the amount of adenine should be equal to the amount of thymine
Rosalind Franklin
discovered the density of DNA and, more importantly, established that the molecule existed in a helical conformation. Her work to make clearer X-ray patterns of DNA molecules laid the foundation forJames Watsonand Francis Crick’s suggestion that DNA is a double-helix polymer in 1953
James Watson
biophysicist who playeda crucial role in the discovery of the molecular structure of deoxyribonucleic acid (DNA)
Francis Crick
important theoretical molecular biologist and played a crucial role in research related to revealing the helical structure of DNA
