Chapter 11 Study Guide Flashcards
Mutagens are often called _________, agents that cause cancer
Carcinogens
Each amino acid is defined within the mRNA by a triplet of nucleotides called a
Codon
The mRNA is read in groups of 3 nucleotides
Codons
The codon _____ acts as a start codon
AUG
There are 3 stop codons
UAA
UAG
UGA
Whereas 61 of the 64 possible triplets code for amino acids, three of the 64 codons do not code for an amino acid; they terminate protein synthesis, releasing the polypeptide from the translation machinery. These are called the _________ ?
Stop codons or nonsense codons
Involves the exchange of DNA from one cell to another
Conjugation
Is an essential enzyme responsible for synthesizing new DNA strands during the process of DNA replication
DNA polymerase
Types of genes an individual carries (genetic makeup of an individual)
Genotype
Expressed genes observable characteristics of an individual based on genotype
Phenotype
DNA ➡️ RNA ➡️ protein ➡️ gives function
Central dogma of genetics
An enzyme called _____, then separates the DNA strands by breaking the hydrogen bonds between nitrogenous bases
Helicase
One strand is made in segments called Okazaki fragments (lagging strand) and are joined together with a
Ligase
Any inheritable change in the DNA is a mutation
Spontaneous mutations are caused by _______
Induced mutations are caused by ______
Replication errors
Mutagens
Are short segments of DNA formed on the lagging strand during DNA replication
Okazaki fragments
An _______ is a segment of DNA to which a repressor protein binds to regulate the expression of a set of genes, often part of the operon.
Operators
Are key elements in the regulation of gene transcription, controlling whether certain genes are turned on or off.
Operators
In bacteria and archea, structural proteins with related functions are usually encoded together within the genome in a block called an _____ and are transcribed together under the control of a single promoter, resulting in the formation of a polycistronic transcript
Operon
A _______ allows close contact between cells
A bridge forms between the cell
Pilus
A _____ is a specific region of DNA that acts as a starting point for gene transcription.
It’s where RNA polymerase binds to begin copying the genetic instructions into mRNA
Promoter
Is the process by which a cell copies its DNA to pass genetic information to the next generation of cells during cell division.
DNA replication
Is an enzyme that synthesizes RNA from a DNA template during the process of transcription
RNA polymerase
Refers to the twisting and coiling of DNA
Supercoiled
Is an enzyme that regulates the overwinding or under winding of DNA during the processes such as replication, transcription, and chromosome condensation.
Topoismerase
In ______, bacteria receive DNA via a bacteriophage
Transduction
In _______, naked DNA in the enviorment is taken up by the cell
Transformation
The DNA may be incorporated into the chromosome or remain as a plasmid in the cytoplasm
Transformation
During ______, a polypeptide chain is made using mRNA as a template
Translation
Also called “jumping genes”
Found in both prokaryotes and eukaryotes
May slo carry genes, such as for antibiotics resistance
Can insert themselves randomly into a chromosome
Transposons
Are segments of DNA that have the ability to move from one location to another because they code for the enzyme transposase
Transposons
What are the two essential functions of DNA ?
Replicate itself for cellular reproduction
Instruct the cell how to make the proteins it needs
The process of producing a protein through transcription and translation is called
Gene expression
Are all genes in a cell expressed at all times ?
No, cells can selectively express genes based on their needs, developmental stage, or environmental conditions