Terms : Hide Images
| 52665906 | euchromatin | a region of DNA that is uncoiled and undergoing active transcription into RNA | |
| 52665907 | heterochromatin | Densely staining condensed chromosomal regions, believed to be for the most part genetically inert. chromatin that remains tightly coiled (and darkly staining) throughout the cell cycle. | |
| 52665908 | double helix | The form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape. | |
| 52665909 | nucleotides | Basic units of DNA molecule, composed of a sugar, a phosphate, and one of 4 DNA bases | |
| 52665910 | DNA bases | adenine, guanine, cytosine, thymine | |
| 52665911 | complementary base pairing | adenine form hydrogen bonds with thymine, cytosine forms hydrogen bonds with guanine | |
| 52665912 | phosphodiester bonds | bonds that join nucleotides in nucleic acids | |
| 52665913 | antiparallel | The opposite arrangement of the sugar-phosphate backbones in a DNA double helix. | |
| 52665914 | ribonucleic acid | (RNA) part of the genetic material that organisms inherited from their parents | |
| 52665915 | helicase | an enzyme that untwists the double helix at the replication forks, separating the two parental strands and making them available as template strands | |
| 52665916 | replication fork | A Y-shaped region on a replicating DNA molecule where new strands are growing. | |
| 52665917 | topoisomerase | A protein that functions in DNA replication, helping to relieve strain in the double helix ahead of the replication fork. | |
| 52665918 | DNA polymerase | An enzyme that catalyzes the elongation of new DNA at a replication fork by the addition of nucleotides to the existing chain. | |
| 52665919 | RNA primase | An enzyme that creates an RNA primer for initiation of DNA replication. | |
| 52665920 | leading strand | the new continuous complementary DNA strand synthesized along the template strand in the mandatory 5' --> 3' direction | |
| 52665921 | lagging strand | The strand in replication that is copied 3' to 5' as Okazaki fragments and then joined up. | |
| 52665922 | okazaki fragments | Short fragments of DNA that are a result of the synthesis of the lagging strand during DNA replication. | |
| 52665923 | DNA ligase | an enzyme that eventually joins the sugar-phosphate backbones of the Okazaki fragments | |
| 52665924 | semiconservative | refers to the fact that half of a newly made DNA is the old template. | |
| 52665925 | ribose | a pentose sugar important as a component of ribonucleic acid | |
| 52665926 | uracil | a nitrogen-containing base found in RNA (but not in DNA) and derived from pyrimidine | |
| 52665927 | mRNA | A type of RNA, synthesized from DNA, that attaches to ribosomes in the cytoplasm and specifies the primary structure of a protein; also called messenger RNA. | |
| 52665928 | rRNA | The most abundant type of RNA, which together with proteins froms the structure of ribosomes. Ribosomes coordinate the sequential coupling of tRNA molecules to mRNA codons; also called ribosomal RNA. | |
| 52665929 | tRNA | The type of RNA that binds to specific amino acids and transports them to the ribosome during protein synthesis | |
| 52665981 | protein synthesis | the formation of proteins by using information contained in DNA and carried by mRNA | |
| 52665982 | transcription | process in which part of the nucleotide sequence of DNA is copied into a complementary sequence in RNA | |
| 52665983 | translation | (genetics) the process whereby genetic information coded in messenger RNA directs the formation of a specific protein at a ribosome in the cytoplasm | |
| 52665984 | sense strand | The strand of DNA that has the code for protein | |
| 52665985 | antisense strand | strand of DNA that is NOT transcribed | |
| 52665986 | RNA polymerase | an enzyme that pries the 2 strands of DNA apart and hooks together the RNA nucleotides as they base pair along the DNA template | |
| 52665987 | exons | expressed sequence of DNA; codes for a protein | |
| 52665988 | introns | sequence of DNA that is not involved in coding for a protein | |
| 52666470 | poly(A) tail | After an mRNA is transcribed from a gene, the cell adds a stretch of A residues (typically 50-200) to its 3' end. | |
| 52666471 | 5' cap | when pre-mRNA is modified the 5 primed end is synthesized first; it is a modified form of a guanine nucleotide | |
| 52666472 | codons | A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code. | |
| 52666473 | anticodon | group of three bases on a tRNA molecule that are complementary to an mRNA codon | |
| 52666474 | A site | holds the tRNA carrying the next amino acid to be added to the chain | |
| 52666475 | P site | one of a ribosome's three binding sites for tRNA during translation. It holds the tRNA carrying the growing polypeptide chain. | |
| 52666476 | E site | One of a ribosome's three binding sites for tRNA during translation. This site is the place where discharged tRNAs leave the ribosome. | |
| 52666604 | peptide bond | covalent bond formed between amino acids | |
| 52666605 | polypeptide | A polymer (chain) of many amino acids linked together by peptide bonds. | |
| 52666606 | stop codons | UAA, UAG, UGA | |
| 52666607 | chaperonins | protein molecules that assist the proper folding of other proteins | |
| 52666608 | chaperon proteins | a type of protein that helps denatured proteins fold correctly | |
| 52666609 | mutation | change in a DNA sequence that affects genetic information | |
| 52702911 | genetic code | the ordering of nucleotides in DNA molecules that carries the genetic information in living cells | |
| 52702912 | point mutations | gene mutations involving changes in one or a few nucleotides | |
| 52702913 | frameshift | A nucleotide is inserted or deleted, changing where the coding for entirely different amino acids. | |
| 52702914 | missense | single base change results in the inclusion of a different amino acid | |
| 52702915 | nonsense | A new nucleotide replaces an existing one and changes the codon so that it codes for the end of the strand with TAA, TAG, or TGA. |
