| 9817606529 | chromosomes | DNA is organized into these, which consist of DNA wrapped around proteins called histones. Found in the nucleus, they direct and control all the processes necessary for life, including passing themselves and their information on to future generations. | | 0 |
| 9817606530 | double helix | What is the shape of DNA? |  | 1 |
| 9817606531 | Watson and Crick | the two scientists that discovered the structure of DNA in 1956 | | 2 |
| 9817606532 | nucleotide | subunit of DNA that consists of a five-carbon sugar, a phosphate, and a nitrogenous base |  | 3 |
| 9817606533 | deoxyribose | the pentagon-shaped sugar in DNA which is linked to a phosphate and a nitrogenous base in a nucleotide |  | 4 |
| 9817606534 | purine | double-ringed nitrogenous base | | 5 |
| 9817606535 | pyrimidine | single-ringed nitrogenous base | | 6 |
| 9817606536 | adenine | a purine (double-ringed nitrogenous base) with a double bond to thymine | | 7 |
| 9817606537 | guanine | a purine (double-ringed nitrogenous base) with a triple bond to cytosine | | 8 |
| 9817606538 | cytosine | a pyrimidine (single-ringed nitrogenous base) with a triple bond to guanine | | 9 |
| 9817606539 | thymine | a pyrimidine (single-ringed nitrogenous base) with a double bond to adenine | | 10 |
| 9817606540 | phosphodiester bonds | bonds that link nucleotides together
bonds between phosphate group and pentose sugar in nucleic acids | | 11 |
| 9817606541 | complementary | The two strands of DNA are ______. This means that if you know the sequence of bases in one strand, you'll know the sequence of bases in the other strand. For example, if the base sequence in one DNA strand is ATC, the base sequence in the ______ strand will be TAG. | | 12 |
| 9817606542 | carbon | Each DNA strand has a 5' end and a 3' end, so-called for the ____ that ends the strand. The fifth ____ in the sugar ring is at the 5' end, while the third ____ is at the 3' end. | | 13 |
| 9817606543 | antiparallel | Because the DNA strands run in opposite directions, this means that the 5' end has a phosphate group and the 3' end has a hydroxyl group. The 5' end of one strand is always opposite to the 3' end of the other strand. The strands are therefore said to be what? | | 14 |
| 9817606544 | hydrogen (bonds) | The DNA strands are linked by what kind of bonds? | | 15 |
| 9817606545 | 2 | How many hydrogen bonds hold adenine and thymine together? | | 16 |
| 9817606546 | 3 | How many hydrogen bonds hold cytosine and guanine together? | | 17 |
| 9817606547 | protein(s) | DNA's main role is to direct the manufacture of what?
DNA → RNA → _____ | | 18 |
| 9817606548 | RNA | DNA passes its information to what intermediate molecule?
DNA → _____ → proteins | | 19 |
| 9817606549 | DNA replication | the copying of DNA
*Step 1:* unwind double helix by breaking H bonds
*Step 2:* DNA topoisomerase cuts and rejoins helix to prevent tangling
*Step 3:* DNA polymerase adds nucleotides
*Step 4:* Okazaki fragments added
*Step 5:* DNA ligase creates continuous strand
*Step 6:* hydrogen bonds form between the new base pairs | | 20 |
| 9817606550 | helicase | this enzyme unwinds the double helix by breaking the hydrogen bonds |  | 21 |
| 9817606551 | replication fork | after helicase breaks the hydrogen bonds and unwinds the DNA, the exposed DNA strands now form this |  | 22 |
| 9817606552 | topoisomerase(s) | Because the DNA helix twists and rotates during DNA replication, another class of enzymes called DNA ______ cuts and rejoins the helix to prevent tangling. | | 23 |
| 9817606553 | DNA polymerase | Which enzyme performs the actual addition of nucleotides alongside the naked strand?
Oddly enough, it can only add nucleotides to the 3' end of an existing strand. | | 24 |
| 9817606554 | RNA primase | Because DNA polymerase can only add nucleotides to the 3' end of an existing strand. This enzyme is necessary to create a short strand of RNA nucleotides called a primer. The primer is later degraded by enzymes, and the space is filled with DNA. | | 25 |
| 9817606555 | leading (strand) | What is the DNA strand called that is made continuously during replication, meaning the nucleotides are steadily added one after the other by DNA polymerase? | | 26 |
| 9817606556 | lagging (strand) | What is the DNA strand called that is made discontinuously during replication, meaning it is made in small pieces of nucleotides so that DNA polymerase can work in the 5' to 3' direction? | | 27 |
| 9817606557 | 5 to 3 direction | Direction in which DNA and RNA is synthesized. | | 28 |
| 9817606558 | 3 to 5 direction | Direction in which the template DNA is read during DNA replication. | | 29 |
| 9817606559 | Okazaki fragments | What are the small pieces of nucleotides added in the lagging strand so that DNA polymerase can be added in the 5' to 3' direction called? | | 30 |
| 9817606560 | DNA ligase | Which enzyme links together the Okazaki fragments to produce a continuous strand? | | 31 |
| 9817606561 | semiconservative | When DNA is replicated, we don't end up with two entirely new molecules. Each new molecule has half of the original molecule. Because DNA replicates in this way, by conserving half of the original molecule in each of the two new ones, it is said to be what? | | 32 |
| 9817606562 | helicase | the enzyme that unwinds our double helix into two strands | | 33 |
| 9817606563 | DNA ligase | the enzyme that brings together the Ozakai fragments and is used during genetic engineering, to insert the DNA fragment containing the gene of interest into the plasmid. | | 34 |
| 9817606564 | transcription factors | these proteins control the transfer of genetic information from DNA to RNA by binding to specific DNA regulatory sequences which in turn will help RNA polymerase bind to the promoter. | | 35 |
| 9817606565 | nucleus | The organelle in eukaryotes where transcription occurs? | | 36 |
| 9817606566 | cytoplasm | Where does translation occur? | | 37 |
| 9817606567 | single (stranded) | Is RNA single or double stranded? | | 38 |
| 9817606568 | ribose | What is the five carbon sugar in RNA instead of deoxyribose in DNA? | | 39 |
| 9817606569 | uracil | What is the nitrogenous base in RNA that replaces thymine? | | 40 |
| 9817606570 | mRNA (messenger) | this type of RNA copies the information stored in the strand of DNA and carries it to the ribosome | | 41 |
| 9817606571 | rRNA (ribosomal) | this type of RNA is produced in the nucleolus and makes up part of the ribosomes | | 42 |
| 9817606572 | tRNA (transfer) | this type of RNA shuttles amino acids to the ribosomes and is responsible for bringing the appropriate amino acids into place at the appropriate time (it does this by reading the message carried by the mRNA) | | 43 |
| 9817606573 | protein synthesis | the process of making proteins that involves three steps:
-transcription
-RNA processing
-translation | | 44 |
| 9817606574 | transcription | This step in protein synthesis involves copying the genetic code directly from DNA. The initial steps are similar to the initial steps in DNA replication. The obvious difference is that, whereas in replication we end up with a complete copy of the cell's DNA, we end up with only a partial copy in the form of mRNA. | | 45 |
| 9817606575 | promoters | transcription begins these special regulatory sequences of the DNA strand; this is the area where RNA polymerase attaches. | | 46 |
| 9817606576 | RNA polymerase | an enzyme that brings free-floating RNA nucleotides to the DNA antisense strand during transcription | | 47 |
| 9817606577 | RNA processing | This step of protein synthesis occurs only in Eukaryotes. During this step, the newly made mRNA molecule's noncoding regions are removed by a spliceosome and it is capped. This process produces a final mRNA that is shorter than the transcribed mRNA. | | 48 |
| 9817606578 | exons | the regions on the mRNA that express the code for the polypeptide to be made | | 49 |
| 9817606579 | introns | the regions on the mRNA that do not express a code for a polypeptide to be made | | 50 |
| 9817606580 | spliceosome | this complex removes introns from the mRNA during RNA processing | | 51 |
| 9817606581 | poly(A) tail and 5' GTP cap | Added to the mRNA during RNA processing to help the mRNA: leave the nucleus, land on the ribosome and protect it from the cytosol. | | 52 |
| 9817606582 | translation | In this step of protein synthesis, the mRNA attaches to a ribosome and "waits" for the appropriate amino acids to come to the ribosome. Once the methionine tRNA is attached to the P site of a ribosome, the A site can be filled by the appropriate tRNA that corresponds to the next codon. As each amino acid is brought to the mRNA, it is linked to its neighboring amino acid by a peptide bond. Termination occurs when the ribosome runs into one of the stop codons. | | 53 |
| 9817606583 | codon | a group of three nitrogenous bases that corresponds to one of the 20 amino acids
The mRNA molecule carries the message from DNA in the form of these. The genetic code is redundant, meaning that certain amino acids are specified by more than one codon. | | 54 |
| 9817606584 | ribosome | Where does translation occur? | | 55 |
| 9817606585 | anticodon | This group on the end of a tRNA molecule has three nitrogenous bases that can base pair with the codon in the mRNA during translation. | | 56 |
| 9817606586 | start codon AUG | initiation of translation occurs when the ribosome runs into one of these | | 57 |
| 9817606587 | stop codon(s) | termination of translation occurs when the ribosome runs into one of three of these | | 58 |
| 9817606588 | primary structure | one of the four structures of proteins: the linear sequence of the amino acids bonded together with peptide/covalent bonds. | | 59 |
| 9817606589 | secondary structure | one of the four structures of proteins: the twisting of the polypeptide that forms either a coil (alpha helix) or a zigzagging pattern (beta-pleated sheets) that occurs with hydrogen bonding in the backbone of the amino acid chain. | | 60 |
| 9817606590 | tertiary structure | one of the four structures of proteins: the polypeptide folds in a three-dimensional pattern that is stabilized by many types of bonds between the R groups of neighboring amino acids. | | 61 |
| 9817606591 | quaternary structure | one of the four structures of proteins: two or more polypeptides get together; not all proteins have this level of structure. | | 62 |
| 9817606592 | nonsense (mutation) | type of mutation in which protein synthesis is terminated early because a stop codon is created. |  | 63 |
| 9817606593 | missense (mutation) | type of mutation in which a codon is altered and produces a different amino acid |  | 64 |
| 9817606594 | silent (mutation) | type of mutation in which a nucleotide is selected which creates a codon that codes for the same amino acid and therefore does not change the corresponding protein sequence |  | 65 |
| 9817606595 | insertion | the addition of bases into DNA
**can cause a frameshift |  | 66 |
| 9817606596 | deletion | the removal of bases from DNA
**can cause a frameshift |  | 67 |
| 9817606597 | duplication | This can result in an extra copy of genes and are usually caused by unequal crossing over during meiosis or chromosome rearrangements. This may result in new traits because one copy can maintain the gene's original function and one copy may evolve a new function. | | 68 |
| 9817606598 | inversion | This can result when changes occur in the orientation of chromosomal regions. This may cause harmful effects if the inversion involves a gene or an important sequence involved in the regulation of gene expression. | | 69 |
| 9817606599 | translocation | This can occur when a portion of two different chromosomes (or a single chromosome in two different places) breaks and rejoins in a way that the DNA sequence or gene is lost, repeated, or interrupted. | | 70 |
| 9817606600 | recombinant DNA | This type of DNA is generated by combining DNA from multiple sources to create a unique DNA that is not found in nature.
A common application of this technology is the introduction of a eukaryotic gene of interest (such as insulin) into a bacterium for production. | | 71 |
| 9817606601 | genetic engineering | the branch of technology that produces new organisms or products by transferring genes between cells | | 72 |
| 9817606602 | restriction enzymes | During genetic engineering, unique sequences, which flank the gene of interest in eukaryotic DNA, are recognized and cut by special enzymes called these. Using these, a cut is made in a plasmid to create a site for insertion of the eukaryotic DNA.
enzymes, naturally occurring in bacteria, that cut DNA at specific recognition sites | | 73 |
| 9817606603 | plasmid | a circular, non-essential bacterial DNA
This can be cut by a restriction enzyme to create a site for insertion of the eukaryotic DNA. Once this has been cut, the eukaryotic DNA fragment containing the gene of interest is inserted into it by the enzyme DNA ligase. | | 74 |
| 9817606604 | transformation | during genetic engineering, the plasmid DNA is combined with bacteria and placed under conditions that favor uptake of the DNA | | 75 |
| 9817606605 | DNA cloning by Recombinant DNA transformation | A process that grows bacteria in order to make copies of a gene or protein of interest. | | 76 |
| 9817606606 | gel electrophoresis | DNA fragments can be separated according to their molecular weight or size using this process. Because DNA and RNA are negatively charged, they migrate through the gel toward the positive pole of the electrical field.
The smaller the fragments, the faster they move through the gel. | | 77 |
| 9817606607 | DNA fingerprinting or profiling | In this process, DNA left at a crime scene are compared to the DNA of suspects. | | 78 |
| 9817606608 | sticky ends | the uneven ends of a double-stranded DNA molecule that has been cut with a restriction enzyme
an end of a DNA double helix at which a few unpaired nucleotides of one strand extend beyond the other
When placed together, the gene is inserted into the plasmid creating recombinant DNA. | | 79 |
| 9817606609 | virus | a nonliving agent capable of infecting a cell
They are considered nonliving because they require a host cell's machinery in order to replicate.
It consists of two main components: a protein capsid and genetic material made of either DNA or RNA. | | 80 |
| 9817606610 | lytic cycle | a virus cycle in which the virus immediately starts using the host cell's machinery to replicate the genetic material and create more viral genome and protein capsids
These spontaneously assemble into mature viruses and cause the cell to lyse, or break open, releasing new viruses into the environment. | | 81 |
| 9817606611 | lysogenic cycle | a virus cycle in which the virus incorporates itself into the host genome and remains dormant until it is triggered to switch into the lytic cycle | | 82 |
| 9817606612 | retrovirus | a virus that uses reverse transcriptase to convert their RNA genomes into DNA so that they can be inserted into a host genome
RNA viruses have extremely high rates of mutation because they lack error-proofing mechanisms when they replicate their genomes of mutation. | | 83 |
| 9817606613 | reverse transcriptase | an enzyme that converts a retrovirus's RNA genomes into DNA so that they can be inserted into a host genome | | 84 |
| 9817606614 | genome | all of the genetic information in an organism; all of an organism's chromosomes | | 85 |
| 9817606615 | prophage or provirus | viral DNA that incorporates itself into the host DNA | | 86 |
| 9817606616 | frameshift mutation | An insertion or deletion of nucletodies can cause a shift in the reading frame of the mRNA | | 87 |
| 9817606617 | operon | A piece of DNA in prokaryotes that consists of a promoter, operator, genes in the same metabolic pathway and a terminator. It is used in gene regulation. | | 88 |
| 9817606618 | repressible operon | A type of operon that is typically on and a metabolite, corepressor, can turn off when enough product is present. | | 89 |
| 9817606619 | inducible operon | A type of operon that will control catabolic pathways and the substrate will turn on the operon. | | 90 |
| 9817606620 | inducer | A metabolite that interacts with the repressor to inactivate it. | | 91 |
| 9817606621 | corepressor | A metabolite that interacts with the repressor to activate it. | | 92 |
| 9817606622 | genome and capsid | Some viruses can have an envelope but all viruses must have these two components. | | 93 |
| 9817606623 | cell differentiation | A cell taking on a specific role because of the activation and silencing of certain genes. | | 94 |
| 9817606624 | antibiotic | A solution that is used to identify which bacteria took in the recombinant plasmid. | | 95 |
