Unit 1; DNA and cell division Flashcards
griffiths experiment
injected some mice with harmless bacteria and some with disease causing bacteria the ones that were injected with this died. he thought that the disease causing bacteria made some kind of poison. he heated the disease causing bacteria up and killed them then injected them in mice; they lived. not poison? he then mixed live harmless bacteria with dead disease causing bacteria and injected that into mice and they died these dead mice were filled with the disease causing bacteria. he called this transformation.
Hershey- Chase experiment
They used radio active markers in bacteriaohage (virus made of protein and DNA that effects bacteria by attaching to the cell and inserting their genetic material)to tell whether or not the genetic information is contained within protein or DNA. They put phosphorus-32 in the DNA and sulphur-35 in the protein. the result was that the bacteria contained the phosphorus-32 therefore the genetic material came from dna
who determined the structure of DNA
james watson and francis chris
what is DNA made from
deoxyribose; a five carbon sugar, phosphate group, and a nitrogenous base; adenine, thymine, cytosine, and guanine.
purines
they have two rings; adenine and gaunine
pyrimidines
one ring; thymine and cytosine
pairing of bases
a with t and they have two hydrogen bonds. g with c and they have three hydrogen bonds.
How is DNA arranged in the cell?
DNA is coiled around protein called histones which makes a bead like structure called nucleosome which forms coils which forms super coils and eventually when cell division occurs(mitosis) they make chromosomes
differences of mRNA
ribose sugar instead of deoxyribose (which has more sugar) it is single stranded. and it contains uracil replacing thymine
genes
coded in DNA instructions that control the productions of proteins in the cell, copies part of the nucleotides from DNA into RNA
transcription
the making of RNA
transcriptase
enzyme that adds the complimentary mRNA nucleotides to DNA
types of RNA
main one you look at mRNA which is messenger RNA and it is a set of instructions for assembling amino acids into proteins. rRNA ribosomal proteins assembled on ribosomes
tRNA transfer during construction of protein tRNA transfers each amino acid to ribosome as it is specified by coded messages in mRNA.
transcription
RNA molecules are produced by copying part of the nucleotide sequence of DNA into complementary sequence. this is a process.
RNA polymerase
an enzyme that is similar to DNA polymerase. during transcription RNA polymerase binds DNA and separates DNA strands then uses the strands as template to make ran. the polymerase binds to promoters which are like signals where it should be bonded to.
Introns
part of RNA that are not involved in coding for proteins. they are cut out from mRNA because they are not needed.
Exon
DNA sequences that are used in RNA to code for proteins.
genetic code
proteins are made by joining amino acids into long chains. the chains are called polypeptides. the order of the amino acids determines the properties of the proteins.