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200 Cards in this Set
- Front
- Back
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As the double helix sepeartes and 2 starnds are produced, what does each new strand act as?
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a template
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What does an old strand attach to once it unwinds?
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a new one
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What is called when each of the complementary starnds of the parental helix is conserved?
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semiconservative replication
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Each new DNA double helix is made of what?
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a starnd of old DNA and a starnd of new DNA
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What does DNA replication produce?
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2 DNA double helices
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What is required for DNA replication?
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20 enzymes and accesory proteins
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For a prokaryote, how many nucleotides are added per second?
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500
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For a human, how many nucleotides are added per second?
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50
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What is the chance there there will be a mistake in the DNA replication process?
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1 in a billion
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What is the DNA replication process so accurate?
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DNA repair enzymes proofread each new strand after synthesis
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DNA starnds are seperated by an enzyme known as what?
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helicase
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What does helicase form?
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a replication bubble
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What is at each end of the replication bubble?
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a replication fork
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Where are new strands being synthesized?
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at the replicatrion fork
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What are the Y-shaped regions of replicating DNA molecules where new strands are growing?
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replication forks
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What initiate new strand sythesis?
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RNA primers
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What is made up by DNA premise?
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RNA primers
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Sythesis of the new strands are by a variety of enyzmes generally referred to as what?
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DNA polymerases
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What direction does sythesis occur in?
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5-3
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Since synthesis occurs in the 5-3 direction what is it known as?
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bidirectional
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Due to its bidirectional nature what are the two diffrent strands referred to as?
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the leading strand and the lagging strand
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Which strand is synthesized in a continuous manner?
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the leading strand
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Which starnd is synthesized in pieces in a discontinous manner?
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the lagging strand
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What are the fragments of the lagging strand referred to as?
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the okazaki fragments
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The okazaki fragments are joined by and enzymes called what?
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DNA ligase
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what are the instructions that tell the cell what to do?
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DNA
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what are the results of DNA instructions?
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proteins
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the study of metabolic defects provided evidence that genes lead to what?
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proteins
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The relationahuip between genes and proteins was first proposed by who in 1909?
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Archibald garrod
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Archibald garrod suggested that some metabolic disorders are caused by a what?
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blocked pathway
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Inherited diseases are the result of a lack of what?
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an enzyme
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What not only stops the production of something we need but may also lead to the accumulation of something we dont want?
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a blocked pathway
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the biochemical pathway for the synthesis of the amino acid aginine involves how many steps?
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2
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Each step in a biochemical pathway is catalyzed by what?
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a diffrernt enzyme
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In what year were the suggestions of Garrod confirmed?
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1930s
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George beadle and Edward tatum conducted an experiment with what?
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bread mold (neurospapora crassa)
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What did george beade and edward tatum demonstarte with bread mold?
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differenent mutants generated by x-rays had the pathways of arginine blocked at diffrenent steps
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What was beadle and tatums formulated hypothesis?
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one-gene-one-enzyme hypothesis
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What was beadle and tatums one-gene-one enzyme hypthesis later clarified into?
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one-gene-one protein
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Where does transcription take place?
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in the nucleous
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Where does translation take place?
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in the cytoplasm
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What is the first step?
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DNA to RNA
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What is the proces of changing DNA to RNA known as?
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transcription
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What is the synthesis of RNA using DNA as a template?
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transciption
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In transcription what is coplementary to the DNA?
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RNA
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RNA is that is synthesized from a gene coding for a protein is known as?
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messenger RNA
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what carries the code for the a protein-coding gene from DNA to ribosomes?
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mRNA
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During transcription of a gene, only one strand of the DNA's two starnd's is read, which one?
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the template strand
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different genes use different starnds as what?
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the template strand
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what is the first step in gene expression?
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transcription
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Transcription transfers the genetic information stored in the DNA genes into what?
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mRNA
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what are the three stages of transcription?
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initiation, elongation, termination
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RNA binds to the promoter region of DNA near the beginning of a gene, which does what?
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seperates the double helix near the promoter
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what synthesizes a chain of 10 ribonucleotides and moves downstream from the promoter as it makes the RNA transcript?
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RNA polymerase
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what travels along the DNA template starnd, catalyzing the addition of ribuose nucleotides into an RNA molecule?
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RNA polymerase
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Which stage of transcription involves RNA polymerase traveling along the DNA templare starnd, catalyzing the addition of ribose nucloetides into an RNA molecule?
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elongation
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The nucleotides in the RNA are what to the template starnd of the DNA?
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complementary
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RNA synthesis is governed by the same base pairing rules as what?
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DNA synthesis
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what is the diffrence between DNA and RNA base synthesis?
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uracil replaces thymine
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How many bases are there in nucleic acids?
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4
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How many amino acids in proteins are there?
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20
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what is the start codon?
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AUG
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What are the three stop codons?
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UGA, UAA, UGA
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each codon specifies one what in the polypeptide chain?
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amino acid
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how many diffrent types of RNAs are involved in gene expression?
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3
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What are the three diffrent types of RNA involved in gene expression?
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tRNA, rRNA, mRNA
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what carries the genetic information from genes to the ribosome sin the cytoplasm?
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mRNA
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what carries the amino acids to the ribosomes and provide the codon-recognition specifically during translation?
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tRNA
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what forms ribosome-sites for polypeptide/protein synthesis?
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rRNA
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What are made up of rRNA and other different proteins?
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ribosomes
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what is always made up of at least one small part and one large part?
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a ribosome
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the smaller subunit of a ribosome has a binding site for what two things?
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mRNA and tRNAf^met
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The larger subunit of a ribosomes has binding sites for what two things?
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2 tRNAs and a catlytic site
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The larger subunit has a catalytic binding site, what is it for?
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joining together amino acids attached to tRNAs
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When is the only time the subunits of the ribosome will come together?
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during protein synthesis
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Translation occurs on what?
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the ribosomes
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during which phase are proteins synthsized according to the genetic meesage of sequential codons in the mRNA?
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translation
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What is a 3-nuclotide sequesnce in mRNa that specifies which amino acid will be added to a growing polypeptide or signal the termination of translation?
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codon
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what two things act as the "interpretor" between the nucleotide "language" of mRNA and the amino acid "language" of proteins?
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tRNA and rRNA
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what are the three stages of transaltion?
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intiation of protein synthesis, elongation of protein snythesis, and termination
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what is the proces sin which the genetic information of a cell is faithfully passes along to the next generation of cells
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cell division
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what does a cell divide into?
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2 daughter cells
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what are the three chracteristics of cell division?
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- replication of DNA
- equal distribution of DNA to opposite ends of the dividing cell - seperation into 2 daughter cells |
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asexual reproduction involves what?
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just one parent
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what are the two types of asexsual reproduction?
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budding and binary fusion
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How do bacteria reproduce?
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binary fission
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What is a prokaryotic cel division?
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binary fission
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What binds at the 5' end of the mRNA and moves along the mRNA searching for a start codon?
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the initian complex
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tRNAf^met has what kind of aniticodon to bind with the AUG start codon?
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UAC
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When the start codon is found the large ribsomal subunit attaches to the small subunit holding Met-tRNA its first tRNA binding site. Why is this significant?
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it is the start of translation
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during elongation, how many amino acids are added at one time?
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one
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what breaks the bond holding met on its tRNA?
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a catalytic site
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after the catalytic site breaks down the met and tRNA what is formed?
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a peptide bond
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AFter the break down of the met and tRNA, what is released?
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tRNA
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During elongation, how many codons are read at one time?
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one
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enzymes in the cytoplasm attach the appropriate amino acid to each tRNA based on what?
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the tRNAs anticodon
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What does the stop codon signal to the mRNA?
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stop protein synthesis
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stop codons do not bind t what?
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tRNA
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When a stop codon is encountered what is released?
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the finished protein and mRNA
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During termination what happens to the ribosomes?
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they disassemble and can be used again to translate another tRNA
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A codon specifies a what?
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an amino acid
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What are changes in the sequence of bases in DNA?
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mutations
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What can result from base pairing during replication?
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mutations
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What can occur due to exposure to mutagens?
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mutations
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What results from nucleotide subtitutions, insertions, or deletions?
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mutations
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mutations involving individual nucleotide changes in DNA are called what?
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point mutations
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WHat is it when one or more nucleotides are inserted into a gene?
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insertion
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what is it called when one or more nucleotides is removed from a gene?
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deletion
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What can affect protein structure and function?
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mutations
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What two things mess up the codons that come after the mutation?
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insertion and deletion
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a protein from a mutated mRNA may be what?
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nonfunctional
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mutations that better adaption to enviroment are favored by what?
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natural selection
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How often do mutations occur?
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they are rare and happen at a very low rate
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the circular dna double helix is attached to what at one point?
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the plasma membrane
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Circular DNA replicates and the 2 DNA double helices attach to what at neraby points?
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the plasma membrane
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What is added in between the attachment point of two circular DNA double helices to push them furthur apart?
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plasma memnbrane
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What grows inward and at the middle of the cell?
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the plasma membrane
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if the organism is single celled than a cell cycle can be the same as what?
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the life cycle
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what is a well ordered sequence of events during which the cell divides, grows and prepares to divide?
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the cell cycle
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during the cell cycle interphase alternates with what?
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mitosis
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what is another name for mitosis?
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m phase
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what kind of activity is there duing interphase?
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high metabolic activity
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chromosomes and organelles are duplicated whithin what?
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interphase
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what happens in the G1 phase of interphase?
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cell growth and diffentiation
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What happens in the S phase of interphase?
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synthesis of DNA; chromosomes are duplicated
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what happens in the G2 phase of interphase?
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cell growth
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what percentage of time dies interphase take?
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90%
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what consists of nuclear division and cytoplasmic division?
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cell division
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what is the division of the nucleaus?
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mitosis
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during the process of mitosis the DNA is equally distributed into what?
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2 daughter nucei
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the division of the nucleaus is usually followed quickly by what?
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cytokinesis
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what is the division of the cytoplasm that forms 2 seperate daughter cellswhich each contain a single nucleuos?
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cytokinesis
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what are the 6 different phases?
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interphase, prophase, metaphase, anaphase, telaphanse and cytokinesis
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during the cell cycle the chromosomes do what?
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replicate
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what are threadlike structures composed of DNA?
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chromosomes
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the genome of what is organized into multiple chromosomes?
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eukaryotic cell
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what is made up of chromosomes which are genes?
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genome
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what are made up of chromatin genes?
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chromosomes
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what are made up of DNA and protein?
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chromatin
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the eukaryotic chromosome has two arms whcih extend from a structure called the what?
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centromere
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what is the centralized region between the arms of a chomosome which joins two sister chromatid?
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centromere
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if the chromosomes are phtographed the pairs can be arranged by what three things to produce a karotype?
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size shape and staining pattern
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what are a pair of chromosomes that have the same size, centromere postion and staining pattern
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homologous chromosomes
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organisms which have their chromosomes arranged in pairs are called what?
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diploid
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what is the condition owhere cells have 2 sets of chromosomes?
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diploid
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each set of chromosomes are derived from a diffrenet what?
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parent
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in the ordinary body cells of many organisms the chromosomes occur in what?
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pairs
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each species has a chracteristic # of chromosomes and the individual chromosomes are distinguished by what three things?
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size zhape and staining pattern
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human body cells contain how many chromosomes?
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46
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how many pairs do human body cells contain?
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23
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how many autosomes do humans have?
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44
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How many pairs of autosomes do humans have?
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22
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some cells have only half of the set of chromosomes and are called what?
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haploid
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what is the condition in which cells contain one set of chromosomes?
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haploid
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what another term for haploid?
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n
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the haploid condition is found in the what?
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gamates
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whaqt is another diploid?
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2n
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what are haploid egg and sperm cells and contain half the # of chromomsomes of ordinary cells?
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gamate
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two haplois gamates unite during fertilization to form what?
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a zygote
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what is a diploid cell that results from the union of two haploid gamates?
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zygote
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what two things result in the alteratins between the haplod and diploid condition?
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meiosis and fertilization
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what is the sequence of stages in an organisms reproductive history, from conceptuion to production of its own offspring?
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life cycle
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what is the phase of nuclear division?
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mitosis (m-phase)
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what phase of the cell cycle is divided into 4 phases?
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the miotic phase (m-phase)
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what are the 4 phases of the miotic phase?
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prophase, metaphase, naphase and telophase
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What are organized on a network of microtubules and seperated?
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du[plicated chromosomes
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In what phase does chromatin condense?
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prophase
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in what phase does a single apparatus form?
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prophase
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what consists of microtublues?
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spindle
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two microtubule organizing centers contain pairs of what?
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centrioles
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in what phase does the nuclear envelope disappear?
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prophase
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in what phase do the chromosomes replicate?
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prophase
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what is made up of 2 sister chramatids?
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chromosomes
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kinetochore microtubules attached kinochore of chromsomes to what?
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the mitotic spindle
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in what phase do polar microtubules radiate towards the cells equator?
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prphase
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in what phase do chromosomes move to and align on the equator of the cell?
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metaphase
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In what phase do sister chromatids seperate and form daughter chromosomes and move toward opposite poles?
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anaphase
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in what phase do daughter chromosomes arrive at the poles?
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telephase
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in what phase to kinetochore mictrotubules disappear?
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telophase
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in what phase do polar microtubulkes elongate?
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telophase
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in what phase is cleavage furrow formed?
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telophase
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In what phase does the daughter nuclear envelope form?
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telphase
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in what phase does chromatin begin de-condensing?
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telophase
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at the end of telophase what is present?
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2 genetically identical daughter nuclei
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the divisoion of the nucleous is usually followed by what?
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cytokinesis
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what is the division of the cytoplasm taht forms two seperate daughter cells?
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cytokenesis
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the mechanism of division of the cytoplasm differs for what two things?
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plants and animals
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the cell divies in two; each daughter cell receives one nucleous and about half of what?
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the cytoplasm
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in animals cleavagefurrow forms near the site of what?
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metaphase plate (cell equator)
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what forms at the inside of the plasma membrane at the ceavge furrow and pinches the parent cell into 2 daughter cells?
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a contractile ring
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in plants the cell plate formation occurs at the cell equator and later what is deposited on both sides?
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a cell wall
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asexual reproduction involves only one what/
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parent
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asexual reproduction produces what?
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exactly identical offspring
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sexual reproduction involves how many parents?
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2
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sexual reproduction gives rise to offspring with what?
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unique combinations of genes
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why would there be a diffrence in opffspring with asexual reproduction?
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mutations
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what is a rare change in the DNA of the genes that creates genetic variety?
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mutation
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what reduces the chromosome # from diploid to haploid
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meiosis
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what are fromed by meiosis?
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egg and sperm cells gamates
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What carry only one set of chromosomes?
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gamates
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