Chapter 9 - DNA Flashcards
Acetylation
Addition of an acetyl group to a histone protein - gene expression is enhanced
Adenine
Nitrogenous base found in DNA and RNA
Anticodon - ensures
Anticodon on a tRNA molecule is made of 3 nucleotides. It is complementary to a specific codon on the mRNA molecule. Ensures tRNA molecule carries the amino acid that aligns with specific codon.
Chromatin
Tangled network of DNA in nucleus of cell that is not dividing.
Chromosome
One of 46 rod like structures that appear in nucleus of somatic cell at commencement of cell division
Coding strand
Strand of DNA molecule that is not used to form mRNA. The mRNA molecule will match the base sequence on the coding strand with Thymine replaced with Uracil.
Codon
Sequence of three nucleotides in mRNA
Cytosine
Nitrogenous base found in DNA and RNA
Guanine
Nitrogenous base found in DNA and RNA
Thymine
Nitrogenous base found in DNA. Replaced with Uracil in RNA in DNA replication
Uracil
Nitrogenous base found in RNA
DNA - determines
Molecule in the nucleus of a cell - determines what proteins a cell can make
DNA ligase
Enzyme that joins short sections of DNA together
DNA polymerase
Enzyme that joins nucleotides together in nuclear replication
DNA replication
Production of an identical copy of the DNA
Double helix
Spiral shape of the DNA molecule
Epigenetics
Altering the expression of a gene without changing the gene structure
Gene
Section of a chromosome that contains the nucleotide sequence, coding for a particular trait
Gene expression
Process where the information in a gene is used to make a product
Histone
Protein which DNA is coiled around to from chromatin
Helicase
Enzyme responsible for separation of DNA strand during replication
mRNA
Messenger RNA. Transfers coded information from the nucleus to the ribosomes
Methylation
Addition of a methyl group to a cytosine base on DNA molecule that results in decreased transcription
mtDNA
Mitochondrial DNA
Nucleosome
Length of DNA wound around 8 histone proteins, forms chromatin
Nucleotide
Unit of phosphate, sugar and nitrogen base that mak eup the DNA molecule
RNA
Ribonucleic acid. Molecule that takes code for amino acids from DNA to the ribosomes
RNA polymerase
Active enzyme during transcription of RNA from DNAS
Start codon
Sequence AUG (methionine), when ribosome reaches codon it starts making protein
Template strand
Strand of DNA that is used to form the sequence of bases in mRNA.
Transcription
Process which mRNA is formed by complementary sequence of nucleotides
tRNA
Transfer RNA. Molecule brings amino acids from the cytoplasm to the ribosome
Translation (protein synthesis)
Production of a protein using the information coded in the mRNA.
Base triplet
Sequence of three bases that is the code for a particular amino acid.
epigenetic factors
external factors that can modify gene expression through methylation and acetylation
Deacetylation
acetyl group is removed from histone tail. some genes require presence of acetyl groups for their transcription - means gene expression is inhibited.
epigenetic tags
small molecules that attach to DNA to make it easier/harder for translation of a gene to occur. Can also switch genes off
promotor sequence
binding site on DNA that initiates the process of transcription by signaling where transcription of a gene should begin
terminating sequence
end of a gene in DNA is marked by a terminating sequence. it instructs the RNA polymerase to stop transcribing DNA to RNA, marks the end of the gene that is being synthesised
