BIOL 1406 exam 3 review

sister chromatid

-one of two attached members of a duplicated eukaryotic chromosome

centromere

-constricted region in eukaryotic chromosome where sister chromatids are attached

nucleosome

-a length of DNA wound around a spool of histone proteins

histones

-type of protein that structurally organizes eukaryotic chromosomes

karyotype

-image of an individual's complement of chromosomes arranged by size, length, shape, and centromere location

bacteriophages

-virus that infects bacteria

composition of nucleic acids

-phosphate groups

-sugar molecules

-nitrogen bases

nucleotides

-in DNA nucleotides contain a five carbon sugar, three phosphate groups, and one of four nitrogen containing bases

>adenine

>thymine

>cytosine

>guanine

nucleotide bonds

-hydrogen bonds

DNA bases

-adenine

-thymine 

-cytosine

-guanine

base pairings

-adenine pairs with thymine

double ringed

adenine and guanine

single ringed

cytosine and thymine

RNA bases

-adenine

-uracil

-cytosine

-guanine

RNA base pairings

-adenine pairs with uracil

-cytosine pairs with guanine

nucleotide substances

-five carbon sugar

-three phosphate groups

-one of four nitrogen containing bases

chargaffs first rule

-amounts of thymine and adenine in all DNA are the same, as are amounts of cytosine and guanine

Chargaff’s second rule

-proportions of adenine and guanine differ among the DNA of different species

purine

adenine and guanine

pyrimidine

cytosine and thymine

purines bind with pyrimidines

-purines bind with pyrimidines

semiconservative replication

-when the DNA is unwound for replication the old strand serves as a template for assembly of the new strand of DNA and each new double helix contains one old strand and one new one

Rosalind Franklin

-rosalind franklin was a biochemist

her contribution to the discovery of DNA structure

-she made the first clear x-ray diffraction image of “wet” DNA

structure discovery

-she used x-ray crystallography

credit for the discovery

-watson and crick took her work

DNA backbone

-sugar-phosphate

reproductive cloning

-technologies produce genetically identical individuals (clones)

somatic cell nuclear transfer

-fuses an adult cell with an enucleated egg

therapeutic cloning

-produces embryos that are used for stem cell research

chromosome number

-the sum of all chromosomes in a cell of a given type

DNA polymerase

-a type of enzyme

DNA polymerases various roles

-assembles a complementary strand of DNA on each of the parent strands

-proofreading DNA replication

DNA ligase

-seals any gaps that remain between bases of the “new” DNA so a continuous strand forms 

DNA strand number

2

RNA strand number

1

messenger RNA (mRNA)

-type of RNA that carries a protein-building message

mRNA message location

-the nucleus

tRNA

-transfer RNA

tRNA job

-delivers amino acids to a ribosome during translation

transcription

-process by which an RNA is assembled from nucleotides using the base sequence of a gene as a template

transcription location

nucleus

translation

-process by which a polypeptide chain is assembled from amino acids resulting in a polypeptide chain that folds into a protein

translation location

cytoplasm

ribosomes importance to mRNA

-the ribosome reads the mRNA sequence and puts it into amino acid chains

ribosome make up

-rRNA

ribosomal subunit number

-two

amino acid protein number

-20

codons

-a nucleotide base triplet that codes for an amino acid or stop signal during translation

anticodons

-a triplet of nucleotides

codon base number

-3

start codon number

>one

>AUG

stop codon number

>three

>UAA
>UAG

>UGA

peptide bonds

-bonds that form between amino acids

gene mutation

-smallscale permanent changes in the nucleotide sequence of DNA

mutation causes

-can result from replication errors, the activity of transposable elements or exposure

introns

 nucleotides sequence that intervenes between exons and is excised during RNA processing

exons

nucleotide sequence that is not spliced out of RNA during processing

genetic code codon number

-64

translation stages

-three

>initiation

>elongation

>termination

promoter

-in DNA a sequence to which RNA polymerase binds

transposable element

-segment of DNA that can spontaneously move to a new location in a chromosome