DNA Flashcards
DNA
Deoxyribosenucleic Acid
Chromatin
Coiled DNA Network
Histones
Protiens DNA tightly coiles around eight protiens for storage.
Mitochondria
Organelles in Cytosol where energy is prouced
Double Helix
2 DNA strans in a twisted spiral shape
Nucleotides
Units of DNA molecule
Nucleotide compontents
Deoxyribose (sugar) molecule, phosphate group and nitrogen base
“A” Nitrogen base
Adenine
T Nitrogen Base
Thymine
C Nitrogen Base
Cytosine
G Nitrogen Base
Guanine
Chromosome
One molecule of tightly coiled DNA
Gene
Section of DNA with a sequence of nitrogeneous bases that codes for a protien
Histone
Protien DNA wraps around to protect/organise it
Nucleosome
Length of DNA wrapped around 8 histone protiens
Dna Replication
Formation of DNA molecules identical to original molecule. Occurs when cell devides
Main steps to dna Replication
Enzyme Helicase breaks hydrogen bonds. DNA polymerase binds to each strand of DNA to provide template. DNA polymerase ads complementary nucleotides.
DNA replication
The biological process of producing two identical replicas of DNA from one original dna molecule
Gene
Section of DNA that containes a sequence of bases that create a protien
Genetic Code
Set of rules by which isformation encoded within genetic material is translate into protiens
Transcription
Process where mRNA is formed using the code from a DNA molecule
Translation
Synthesis of protien using infomation that is coded in the mRNA
Types of RNA in protien Synthesis
Messenger RNA & Transfer RNA
Messanger RNA
Formed in the nucleus using DNA code and moves to cytoplasim and binds to a ribosome
Transfer RNA
Located in Cytoplasm. brings amino acids to the ribosome during protien synthesis
Codon
3 bases on the mRNA
Epigenethics
The study of changes in organisms caused by modification of gene expression
DNA methhylation
Addition of a methl group to a cytosine which causes DNA to condense. Prevents transcription
Histone Acetylation
Addition of an acetyl group to histone protien tail. Histone becomes neagative and repels DNA. DNA will loosen and becomes accessible to transcription
Deacetylation
Acetyl group is removed. DNA is attracted to Histone and is not accessible to transcription factors
Cell Devision
Process where parent cell evides into two daughter cells
Mitosis
Occurs in somatic cells, producing cells w/ a diploid number of chromosomes
Meiosis
Occurs in sex organs and produces sex cells with haploid number of chromosomes
Cell Cycle in Eukaryotes
Interphase, M-pHase
M-Phase
Consisting of Mitosis and cytokinesis
First gap Phase (G1)
Cell increases inside and makes the mRNA and protiens needed for S phase
Synthesis (s)
The Cell duplicates its genetic material
Second Gap Phase (G2)
Nucleus is well defined, rapid cell growth and protien synthesis. Prepares for Mitosis
Interphase key points
- DNA visable as chromatin
- DNA Is replicated
- Centriols replicate
- Nuclear membrane still intact
- Rapid cell grown and protien synthesis (eg helicase, histones, polymerase)
Prophase key points
- Nuclear membrane disappears
- Chromatin condenses into Chromosomes (which have duplicated)
- 2 sister chromatids are joined at the centromere
- Centrioles start moving to opposite poles
- Spindle Forms
Metaphase
- Chromosomes line up to the equator of the cell
- Spindle fibers attach to each centromere on chromosomes
Anaphase
- Spindle fibers retract to pull sister chromatis apart
- Becoming distinct chromosomes at poles of cell
- Cell elongates
Telophase
- There is now a ful lset of chromosomes at each end of the cell
- Spindle dissapears
- Nucleus forms around chromosomes
- End of telophase marks cytokinesis
