GENES Flashcards
Gene:
A nucleotide sequence in a DNA molecule that contains the instructions to make a
-Protein
-Specialized RNA molecule
Each of the 46 chromatin molecules in the nucleus consists of the?
DNA double helix and histone proteins
Chromatin
Occupies majority of volume of nucleus
Histone proteins form
Chromatin
Each strand stores?
Genes
This increases the number of genes the double helix contains
The human genome:
The nucleus and mitochondria contain DNA
The 46 DNA molecules in the nucleus contain a total of:
~19,000 protein coding genes
~29,000 RNA coding genes
Where do we inherit mitochondria from?
Mom
Each DNA molecule in the mitochondrion contains:
-13 protein coding genes
-24 RNA coding genes
Nucleus DNA characteristics
-Ends are protected
-Linear form
Mitochondria DNA characteristics
Circular DNA molecule
4 nucleotides →
64 codons
The ____________ sequence of the coding strand of the gene determines the _____ _______ sequence of the protein the gene encodes
Nucleotide; amino acid
The ________________ sequence of the coding strand of the gene determines the __________ sequence of the RNA molecule the gene encodes
Deoxyribonucleotide; ribonucleotide
Gene expression
The ability of the cell to activate and deactivate one or more genes in response to a signal (ligand)
Gene expression enables the cell to:
-Activate a gene when it needs the protein or a higher protein concentration
-Deactivate a gene when it does not need the protein or has an adequate concentration of the protein
The cell responds to some signals (ligands) by…
Changing the patterns of gene expression
-The cell must synthesize the proteins, and/or specialized RNA molecules, necessary to respond to the signal
The structure of the eukaryotic gene
-Promoter
-Transcription start site
-Coding region
-Terminator
-Transcription stop site
Promoter
Regulator region of the gene that controls gene activation and deactivation
Transcription initiation/start site
It instructs the cell where to begin reading the instructions in the gene
Transcription termination/stop site
It instructs the cell where to stop reading the instructions in the gene
Coding region
-Contains the exons that determine the amino acid sequence of the protein the gene encodes
-It contains other sequences between the exons called introns
