Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
65 Cards in this Set
- Front
- Back
Eukaryote
|
- cells contain their genetic material inside a nucleus
- includes large, complex organisms - nucleus separates transcription and translation - undergoes mitosis and meiosis |
|
Nucleotide
|
- basic chemical unit in nucleic acids
- four nucleotides make up DNA - if nucleotide sequence altered, protein may be altered - purines = adenine and guanine - pyrimidines = cytosine and thymine |
|
Base Pairs
|
- pair of nucleotides form by complementary base pairing of a purine and pyrimidine
- A --> T - G --> C - surfaces are chemically distinct, allowing other specific molecules to bind to them |
|
Chargaff's Rule
|
- A = T and G = C
- Total # of Purines = Total # of Pyrimidines |
|
Double Helix
|
- stores an organism's genetic information
- right-handed - antiparallel - minor and major grooves - sugar-phosphate "backbones" held together by hydrogen bonding - complimentary base pairing - 5' end = free, phosphate - 3' end = free, hydroxyl |
|
Genome
|
- the full DNA sequence of an organism
- divided into pieces called chromosomes - haploid set of chromosomes in a gamete - remains constant, but gene expression varies in space and time |
|
Eukaryotic Genome
|
- larger --> more protein-coding genes
- contain numerous repetitive DNA sequences that do not code for polypeptides |
|
Chromosomes
|
- the DNA molecule that contains most or all of the genetic information of a cell or virus
- chromosome number and structure can change without having a major effect on genome size or content - has an ori, centromere region, and telomeric sequence to maintain chromosome integrity |
|
Barr body
|
- one of X chromosomes in each cell of female is transcriptionally inactivated in early embryonic development
- reason why transcription is nearly same in both males and females |
|
Sister Chromatids
|
- each of a pair of newly replicated chromatid
- after replication --> held together by cohesin - by metaphase --> cohesin removed, except for at centromere - by anaphase --> the enzyme separase hydrolyzes the remaining cohesin and chromosome separate |
|
Haploid
|
- having a chromosome complement consisting of just one copy of each chromosome
- two haploid gametes fuse to form a zygote in fertilization |
|
Diploid
|
- having a chromosome complement consisting of two copies of each chromosome
- zygotes are diploid --> may divide either by meiosis or mitosis --> new mature organism develops that is capable of sexual reproduction |
|
Aneuploidy
|
- a condition in which one or more chromosomes or pieces of chromosomes are either lacking or present in excess
- trisomic of chromosome 21 = Down syndrome |
|
Polyploidy
|
- the possession of more than two entire sets of chromosomes
- may be produced by artificial breeding or by natural accidents - desirable trait in plants because leads to more robust plants |
|
Duplication
|
- a mutation in which a segment of a chromosome is duplicated, often by the attachment of a segment lost from its homolog
- would arise if homologous chromosomes broke at different positions and reconnected to the wrong partners |
|
Deletion
|
- result form the removal of part of the genetic material
- consequences can be severe unless they affect noncoding DNA or unnecessary genes |
|
Inversion
|
- a segment of DNA may be removed and reinserted into the same location in chromosome, but "flipped" end over so that it runs in the opposite direction
- can result from breaking and rejoining of chromosomes |
|
Reciprocal Translocation
|
- interchange of chromosome segments between two non-homologous chromosomes
|
|
Gene
|
- a unit of genetic function which carries the information for a single polypeptide or RNA
|
|
One-gene, One-enzyme Relationship
|
- genes act through the production of enzymes, with each gene responsible for producing a single enzyme that in turn effects a single step in a metabolic pathway
|
|
One-gene, One-polypeptide Relationship
|
- the function of a gene is to inform the production of a single, specific polypeptide
|
|
Transcription
|
- the information in a DNA sequence is copied into a complementary RNA sequence
|
|
Translation
|
- the process by which a sequence of nucleotide triplets in a mRNA gives rise to a specific sequence of amino acids during protein synthesis
|
|
Amino Acid
|
- an organic compound containing both NH2 and COOH groups
- proteins are polymers of amino acids |
|
Adapter Molecule
|
- contains an anticodon complementary to the codon in mRNA
- binds a specific amino acid and recognizes a specific sequence of nucleotides |
|
Protein
|
- long-chain polymer of amino acids with twenty different common side chains
|
|
Ribosome
|
- a small particle in the cell that is the site of protein synthesis
|
|
Polypeptide
|
- a large molecule made up of many amino acids joined by peptide linkages
- large polypeptides are called proteins |
|
Messenger RNA (mRNA)
|
- carries a copy of a gene sequence in DNA to the site of protein synthesis at the ribosome
- must be translated in the correct reading frame |
|
Ribosomal RNA (rRNA)
|
- catalyzes peptide bond formation and provides structural framework for the ribosome
|
|
Transfer (tRNA)
|
- carries amino acids to the ribosome for assembly into polypeptides
- charged tRNA will deliver appropriate amino acid to join the elongating polypeptide product of translation - must read mRNA codons correctly - must deliver the amino acids that correspond to each mRNA codon |
|
microRNA
|
- a small, noncoding RNA molecule that binds to mRNA to inhibit its translation
- important regulators of gene expression |
|
RNA Polymerase II
|
- enzyme in eukaryotic cells that catalyzes the transcription of DNA to synthesis precursors of mRNA, most snRNA, and microRNA
|
|
Transcription Factors
|
- binds to specific DNA sequences, thereby controlling the movement of genetic information from DNA to mRNA
- allows RNA Polymerase II to perform transcription |
|
TATA Box
|
- a promoter DNA sequence crucial in forming the transcription intiation complex
|
|
Exon
|
- portion of DNA molecule that codes for part of a polypeptide
- expressed regions - interspersed with the coding sequences |
|
Intron
|
- portion of a coding region in gene that is transcribed into pre-mRNA but is spliced out prior to translation
- intervening regions - interrupt, but do not scramble DNA sequence |
|
Splicing
|
- transcripts of introns are excised through the action of snRNPs
- last stage of RNA processing in eukaryotes - increases protein diversity |
|
Spliceosome
|
- result of binding of snRNPs to consensus sequences bordering the introns on the pre-mRNA
- series of proteins binding |
|
Start Codon
|
- the mRNA triplet (AUG) that acts as a signal for the beginning of translation at the ribosome
- contains three consecutive nucleotides - determines reading frame |
|
Initiator tRNA
|
- initiates protein synthesis by binding to the amino acid methionine and delivering it to the small ribosomal unit
- employed in initiation step of protein synthesis - attaches to ribosome's P site |
|
Stop Codon
|
- any of the three mRNA codons that signal the end of protein translation at the ribosome
- UAG, UGA, UAA |
|
Epigenetics
|
- the scientific study of changes in the expression of a gene or set of genes that occur without change in the DNA sequence
- changes are reversible, but sometimes stable and hereditary - includes DNA methylation and chromosomal protein alterations |
|
Histones
|
- DNA is wrapped around it to produce chromatin
- forms core of nucleosome - the structural unit of a eukaryotic chromosome |
|
Cytosine Methylation
|
- impedes transcription
- turn genes "off" - important for transposon silencing |
|
Transposon
|
- sequences of DNA that can move or transpose themselves to new positions within the genome of a single cell
|
|
Zygote
|
- the cell created by the union of two games, in which the gamete nuclei are also fused
- earliest stage of the diploid generations - result of fertilization |
|
DNA Polymerase
|
- any of a group of enzyme that catalyze the formation of DNA strands from a DNA template
|
|
Carl Linnaeus (1707-1778)
|
- father of taxonomy
- established conventions for naming of living organisms using binomial nomenclature - developed a hierarchical system of classification of organisms |
|
Gregor Mendel (1822-1884)
|
- father of modern genetics
- demonstrated that the inheritance of certain traits in pea plants follows particular patterns --> laws of Mendelian inheritance |
|
Charles Darwin (1809-1882)
|
- theory of natural selection
- all life is a continuous struggle in which on the fittest can survive - descent with modification - Origin of Species --> theory of evolution |
|
Watson and Crick (1953)
|
- described the double helix structure of DNA
- the solution to the structure of DNA achieved through model building - structure is double-stranded, right-handed, antiparallel, and outer edges of nitrogenous bases are exposed in major and minor grooves |
|
Beadle and Tatum
|
- worked to determine whether each gene determines an enzyme in a biochemical pathway
- confirmed Garrod's one-gene, one-enzyme hypothesis - if an organisms cannot convert one particular compound to another, it lacks an enzyme required for conversion |
|
Gene Structure
|
- coding region (makes structure)
- regulatory region (enhancers, promoter) |
|
DNA Sequences Act As:
|
- binding sites for proteins
- a template for RNA production - signals for RNA processing |
|
DNA Methylation
|
- play major role in cancer
|
|
Promoter
|
- special sequence of DNA to which RNA Polymerase binds very tightly
- tells where to start transcription and which strand of DNA to transcribe |
|
Mendelian Laws of Inheritance
|
- every individual possesses a pair of alleles passed down by each parent
- separate genes of separate traits are passed down independently of one another |
|
Enhancer
|
- element that, upon binding with transcription factors, can enhance transcription
- transcription factors = transcriptional activators |
|
Silencer
|
- element that, upon binding with transcription factors, can repress transcription.
- transcription factors = repressors |
|
Response Element
|
- recognition site of certain transcription factors
|
|
Transcriptional Region
|
- part of DNA to be transcribed into RNA molecule
|
|
Regulatory Region
|
- trans-regulatory = DNA sequences that encode transcription factors
- cis-regulatory = binding sites of transcription factors that can affect transcription |
|
Transcriptional Region
|
- part of DNA to be transcribed into RNA molecule
|
|
Regulatory Region
|
- trans-regulatory = DNA sequences that encode transcription factors
- cis-regulatory = binding sites of transcription factors that can affect transcription |