MODULE *: DNA, cell cycle, & cancer

name and identify the three nucleotide bases

DNA

long molecule that carriers genetic information

what is DNA made out of

nucleotides

nucleotides

building blocks of nucleic acids (DNA + RNA) that store and transmit genetic info.

what forms the backbone of DNA

phosphate and sugar molecules

who discovered relative amounts of adenine thymine, and cytosine and guanine

erwin chargaff

who found patterns in DNA and the double-helix shape

rosalind franklin

who found bonds between adenine, thymine, and cytosine and guanine which fit in the double helix structure

watson and crick

apoptosis

cell self destructs

what happens when a cell has a problem that can not be fixed

apoptosis

DNA polymerase

adds complementary nucleotides

DNA helicase

“unzips” DNA

step by step process of DNA replication

1. helicase unzips dna

2. DNA polymerase adds complementary nucleotides

3. dna polymerase attaches to exposed strands

4. new strands are proof read

5. two identical dna strands

mRNA

carriers instructions from DNA in nucleus to the ribosome (cytoplasm)

tRNA

carries amino acids to ribosome

polypeptide chain

chain of amino acids that folds into proteins

codon

three nucleotide sequence on mRNA that codes for single mRNA

transcription

synthesis of RNA → DNA

translation

mRNA decoded and protein produced

what is transcription and translation for

convert the genetic instructions in DNA into functional proteins

type of RNA virus that uses reverse transcriptase to convert RNA to DNA in host cell to insert hosts genome

retrovirus

coverts single stranded RNA into complementary dna

reverse transcriptase

viral enzyme that carries DNA through nuclear pore into helper T

nicks DNA to insert itself into host cell

integrase

enzyme that breaks up polyprotein chain

protease

segments of nucleotides composed of DNA that synthesizes proteins

gene

permanent structural change in an organisms DNA sequence

mutation

normal genes that promote cell growth, division, and survivalo

proto oncogenes

mutated genes that acts as accelerators that drive cell growth

oncogenes

normal genes that acts as a break pedal for cell growth, can initiate cell death

tumor supressor genes

how does cancer occur?

• mutations disrupt proto oncogenes becoming oncogenes which promote uncontrollable cell growth

• tumor suppressor genes which normally act as brakes become damaged or inactive

  • TSG fails → growth signals constantly active → tumor → cancer

structure of DNA during cell cyle: G1

loose uncoiled chromatins

structure of DNA during cell cycle: s phase

two identical sister chromatids

structure of DNA during cell cycle: prophase

condenses, coils, visible chormosomes

structure of DNA during cell cycle: metaphase

chromosomes fully condensed

structure of DNA during cell cycle: anaphase

sister chromatids separate

structure of DNA during cell cycle: telophase

uncoils into chromatin

chromosomes:

composed of DNA and proteins, tightly packed for division

chromatin

complex of DNA, loose working from of DNA

chromatid

one half of duplicated chromosome (copy)

genome

the complete set of genetic instructions (DNA) found within a cell

post-transcriptional modifications: 5’ cap added to begining

helps ribosomes recognize start sequence

post transcriptional modifications: poly a tail added to end of a gene

helps ribosomes recognize end of gene and detach

post transcriptional mod: splicing (introns and exons spliced)

one gene=more than one protein

explain car T cell therapy

1. collect patients T cells and white blood cells

2. T cells instructed to produce CARS on surface = car t cells

3. T cells bound → CAR signaling domains begin chain reaction and activate killer function to destroy cancer cells

4. CARS bind to marker on cancer cells and cluster tgt.

5. CAR signaling domain activated and releases toxic chemicals