bio test 2

a site where the transcription enzyme, RNA polymerase, attaches and initates transcription, determines which of the two strands of the DNA double helix is used as the template in trascription

DNA control sequence, acts as a switch, determines whether RNA polymerase can attach to the promoter and start transcribing the gene

cluster of genes with related functions, exist ONLY in prokaryotes

protein that turns off transcription, functions by binding to the operator and physically blocking the attachment of RNA polymerase to the promoter

ocated outside the operon, codes for the repressor

activatorsproteins that turn operons on by binding to DNA, make it easier for RNA polymerase to bind to the promoter

crucial aspect of DNA packing, account for about half the mass of eukaryotic chromosomes --> small proteins grouped and wrapped around a DNA strand to form a nucleosome

consists of DNA wound around a protein core of 8 histone molecules

eukaryotic RNA polymerase requires the assistance of these proteins, such as activator proteins

DNA control sequences, part of the first step in initiating gene transcription --> binding of activator proteins to these

small RNA molecules that can bind to complementary sequences on mRNA molecules

procedure that involves injecting miRNa into a cell that can turn off expression of a gene with a sequence that matches the miRNA

can cause cancer when present in a single copy in the cell

normal gene that has the potential to become an oncogene

proteins they encode help prevent uncontrolled cell growth/tumors

variation in the lenght of a restriction fragment, produced when homologous DNA sequences containing SNPs are cut up with restriction fragments

the synthesis of RNA under the direction of DNA

the synthesis of protein under the direction of RNA

the genetic instructions for the amino acid sequence of a polypeptide chain are written in DNA and RNA as a series of nonoverlapping three-base "words"

transcription enzyme, links together the growing chain of RNA nucleotides during transcription, using a DNA strand as a template

that signals the end of the gene

the type of ribonucleic acid that encodes the genetic information from DNA and conveys it to ribosomes, where the information is translated into amino acid sequences

internal non-coding regions

coding regions, the parts of a gene that are expressed

the removal of introns and joining of exons in eukaryotic RNA, forming an mRNA molecule with a continuous coding sequence, occurs before mRNA leaves the nucleus

a type of ribonucleic acid that functions as an interpreter in translation --> each molecule has an anticodon, picks up a specific amino acid, and conveys the amino acid to the appropriate codon on mRNA

structures in the cytoplasm that position mRNA and tRNA close together and catalyze the synthesis of polypeptides

a type of ribonucleic acid consisting of nucleotide monomers with a ribose suger and the nitrogenous bases A, C, G, U; usually single-stranded, fuctions in protein synthesis, gene regulation

specific codon that an mRNA molecule binds to where translation is to begin on the mRNA molecule

in mRNA, one of the tree triplets (UAG, UAA, UGA) that signal gene translation to stop

a mutation in a gene that changes a codon to one that encodes for the same amino acid as the original codon --> the amino acid sequence of the resulting polypeptide is thus unchanged

a change in the nucleotide sequence of a gene that alters the amino acid seqeunce of the resulting polypeptide --> a codon is changed from encoding one amino acid to encoding a different amino acid

a change in the nucleotide sequence of a gene that converts an amino-acid-encoding codon to a stop codon --> results in a shortened polypeptide

Steps in Gene Expression include what?

Enzyme induction is a process in which a molecule induces the expression of an enzyme

Repression, in metabolism, a control mechanism in which a protein molecule, called a repressor, prevents the synthesis of an enzyme by binding to—and thereby impeding the action of—the deoxyribonucleic acid that controls the process by which the enzyme is synthesized

allosteric regulation (or allosteric control) is the regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active sit

2nd messenger of biological processes,

DNA sequence that indicates where a genetic sequence can be read and decoded. It is a type of promoter sequence, which specifies to other molecules where transcription begins

protein that increases gene expression by binding to an activator (transcription factor) which contains a DNA binding domain.

is the process where an acetyl functional group is transferred from one molecule (in this case, Acetyl-Coenzyme A) to anothe

Alternative splicing, or differential splicing, is a regulated process during gene expression that results in a single gene coding for multiple proteins.

a compound found in living cells that plays a role in the degradation of defective and superfluous proteins. It is a single-chain polypeptide.

The main function of the this is to degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks peptide bonds.

are enzymes that synthesize DNA molecules from deoxyribonucleotides, the building blocks of DNA.

essential during DNA replication because they separate double-stranded DNA into single strands allowing each strand to be copied.

enzyme that creates a primer on a DNA strand by adding RNA nucleotides to the strand according to the DNA template sequenc

an enzyme that brings about ligation of DNA or another substance.

enzymes that participate in the overwinding or underwinding of DNA.

enzyme within the class of topoisomerase that relieves strain while double-stranded DNA is being unwound by helicase

distinctive structures found at the ends of our chromosomes

involves the removal or "splicing out" of certain sequences referred to as intervening sequences, or introns

a sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA.

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells

type of asexual reproduction in prokaryotic cells an adult cell splits in half creating two new cells

stages of Cell Cycle

the resting phase between successive mitotic divisions of a cell, G1, S, and G2 phases happen in this cell phase

first stage of cell divisions, during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears

second phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells, nuclear envelope breaks down

3rd stage in mitosis the chromosomes, guided by the spindle fibers, line up in the middle of the dividing cell.

4th phase of mitosis,  spindle apparatus pulls the two chromatids of each chromosome apart and drags them toward opposite poles of the cell.

fifth and final phase of mitosis, the process that separates the duplicated genetic material carried in the nucleus of a parent cell into two identical daughter cells.

physical process of cell division, which divides the cytoplasm of a parental cell into two daughter cells, happens at the end of mitosis or meiosis

organelle that serves as a microtubule organizing center during division. It's duplicated during S phase, and the two copies move to opposite sides of the cell.

The spindle apparatus is the collective term for all the spindle fibers that form during mitosis or meiosis. These spindle fibers are responsible in moving and segregating the chromosomes during nuclear division.

one of the pair is from mother other father. The maternal and paternal chromosomes in a homologous pair have the same genes at the same loci, but possibly different alleles.

any chromosome that is not a sex chromosome

a mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.

a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum.

(of a cell or nucleus) having a single set of unpaired chromosomes.(of an organism or part) composed of haploid cells.

) containing two complete sets of chromosomes, one from each parent.

the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei

is a multiprotein complex, specifically a ribonucleoprotein, which incorporates one strand of a single-stranded RNA (ssRNA) fragment, such as microRNA (miRNA), or double-stranded small interfering RNA (siRNA).