Chapter 18.1 DNA Structure and Replication

Terms:

deoxyribonucleic acid- DNA, has deoxyribose sugar, has two strands(double helix), Has C, G, A, and T

ribonucleic acid- RNA, ribose sugar, single-stranded, C, G, A, and U bases

• several different types, because it can assume different structures ex. mRNA, tRNA…

The transforming principle- an experiment conducted by Frederick Griffith which demonstrated that bacteria can be re-programmed through a process called transformation. - suggested that something inside the cell must be responsible for its programming and that this molecule could be transferred from cell to cell.

nucleotides- The basic building block of nucleic acid,

Chargaff’s rule- all double helix DNA will have the same amount of A and T as well as C will be the same amount as G

complementary base pairs- Adenine binds to thymine and guanine binds to cytosine

antiparallel- strands run in opposite directions, parallel to one another, twist in a complete DNA structure, forming a double helix. It runs 3'-5' and 5'-3' linkage.

Genome- The sum of all the DNA that is carried in each cell of an organism

Gene- is a functional sub-unit of DNA that directs the production of one or more polypeptide (protein)

replication- the process by which the genome's DNA is copied in cells.

Total genome- is about 3 billion base pairs and includes about 20-25 thousand genes

DNA replication- During the S phase of interphase, a cell replicates its entire genome in order to produce a new cell with an identical set of DNA. - each strand of DNA serves as a template for the creation of its complementary strand. - said to be semi-conservative

semi-conservative- that is, each new molecule of DNA contains one strand of the original DNA molecule

replication origin- a sequence of DNA at which replication is initiated

helicases- nucleic acid motor that untwists the double helix and separates the two DNA strands

replication bubble- an unwound and open region of DNA where DNA replication occurs.

replication fork- the area where the replication of DNA will actually take place.

DNA polymerase- an enzyme that creates DNA molecules by assembling nucleotides, the building blocks of DNA

elongation- The DNA metabolic process in which an existing DNA strand is extended by activities including the addition of nucleotides to the 3' end of the strand.

Chapter 18.2

Gene expression- For a segment of DNA to be expressed by a cell, it must first be transcribed into mRNA and then translated into a sequence of amino acids (a protein). This is referred to as the “central dogma” of gene expression. although all cells contain the same DNA, not all cells behave the same

amino acids- molecules that combine to form proteins

genetic code- the instructions contained in a gene that tells a cell how to make a specific protein.

transcription- the information in a segment of double-stranded DNA is copied into a single strand of mRNA. - takes place within the nucleus of a cell. - only one strand of the DNA (the coding or “sense” strand) is transcribed into mRNA - initiated when RNA polymerase binds to the promoter region of the coding strand and begins to add complementary base pairs in the 5’ to 3’ direction- Thymine is replaced by uracil (U’s instead of T’s). - Once RNA polymerase reaches a termination sequence, the mRNA strand is complete and can leave the nucleus to be translated into a protein.A sense strand is IDENTICAL the mRNA, except the T in DNA is U in RNA (because there is no T)

message RNA(mRNA)- a type of single-stranded RNA involved in protein synthesis.

transfer RNA(tRNA)- serves as a link (or adaptor) between the messenger RNA (mRNA) molecule and the growing chain of amino acids that make up a protein.

translation- the process of protein synthesis by ribosomes in the cytoplasm or endoplasmic reticulum

codon- A group of 3 base pairs

RNA polymerase-

promoter-

anticodon-

ribosomal RNA(rRNA)—

genomics-

proteomics-

Chapter 18.3

Mutation-

somatic cell mutation-

germline mutation-

point mutation-

silent mutation-

mis-sence mutation-

nonsense mutation-

frameshift mutation-

mutagen-

physical mutagen-

chemical mutagen-

carcinogenic-

mitochondrial DNA-

genetic engineering-

recombinant DNA-

restriction enzyme-

restriction endonuclease-

restriction fragment-

gel electrophoresis-

DNA fingerprint-

Chapter 18.4

biotechnology-

DNA microarray-

copy DNA (cDNA)-

transgenic-

bioremediation-

clone-

ultrasound-

amniocentesis-

chorionic villi sampling-

genetic marker-

DNA probe-

gene therapy-

DNA vector-

somatic gene therapy-

germ-line therapy-