Study Guide For #2 Testj Flashcards
What are the two major functions of DNA
Replication
Directs protein synthesis
Why does DNA replicate
To allow cell division
- growth
- repair
- reproduction
How does DNA replicate
1) unzip and unwind
- helicase splits the whole DNA molecule
2) complimentary base pairing
- new nucleotides form hydrogen bonds with the exposed bases
3) DNA polymerase joins together the new nucleotides to form DNA
What does Semiconservative mean?
1/2 old 1/2 new
What is cloning and what are some examples
A type of asexual reproduction
Plants: spores, cuttings
Animals: sponges use fragmentation
Anemone use binary fission
What are the 2 steps of protein synthesis and what do they result in
Transcription: DNA-mRNA
Translation: mRNA- 1• protein
Describe transcription
- occurs inside the nucleus
- DNA Is used to build a segment of mRNA
1) DNA unwinds and unzips one gene
2) Complementary base pairing using RNA nucleotides - one side is used
3) DNA polymerase joins together the RNA nucleotides to form mRNA - mRNA is released from DNA
- DNA zips back up
What is a gene
One segment of DNA that codes for something
When is mRNA processed
Before it leaves the nucleus during transcription
What are exons
Useful code
What are introns
Useless code
What happens during Translation
- occurs at a ribosome
1) mRNA attaches to the ribosome with 2 codons
2) tRNA molecules join tot the exposed codons at the ribosome with complimentary anticodons
3) Ribosome shifts over one codon on the mRNA strand - one tRNA molecule leaves without its amino acids
How are cancer cells different from normal cells
Constantly dividing (unspecialized anaphase=disorganized growth)
Large nucleus
Lack contact inhibition (form tumors)
Cause vascularization (cause blood vessels to grow towards the tumors)
Metastasize (spread in body)
Cancerous tumors
Benign:
Usually slow growing
Non invasive (self contain)
Does not spread (metastasize)
Malignant:
Usually rapid growth
Invasive
Will metastasize (after a while)
What are the two stages of Carcinogensis
1) initiation
A mutation in a gene that controls cell division (proto-oncogene- oncogene)
Radiation, chemicals, virus
2) promotion
Removal of the control of the oncogenes
Oncogene- cell becomes cancerous
Additional mutation, decrease in body immunity, poor health
Treatment of cancer
Prevention
Early detection
Screening (mammograms, Pap smear,prostate)
What are some signs of cancer
Change in mole Sore that does not heal Persistent cough Difficulty swallowing Change in bowl movements Unusual discharge Body lumps
How to remove cancer
Servicial removal
Chemo therapy
radiation therapy
What is bioengineering and how is it done
Altering the DNA of an organism for human use
Step 1: heat stress bacteria so they will release plasmids
Step 2: use restriction enzymes to open up the plasmid DNA
Step 3: use restriction enzymes to remove a gene of interest from another organism
Step 4: use DNA glue (ligase) joins together gene of interest and plasmid
Step 5: heat stress is used so bacteria will take in recombinant DNA
What are some uses of bioengineering
Bacteria
-to make new proteins(insulin, tPA– blood clot, HGH– human growth hormone)
-to give new trait (oil digestion)
Plants
-easy to bioengineer (agrobacterium, asexual reproduction)
-resistance to environmental factors in crops
Animals
-hard to bioengineer (zygote must be used, no easy vector)
-knock out mice, enviro-pigs, increased growth
When do humans use DNA technology
1) DNA fingerprints
2) DNA screening
3) gene therapy
What is a substitution mutation
Changes one letter= changes one amino acid
What is a deletion mutation
Removes one letter=changes all amino acids after
What is a addition mutation
Adds a letter= changes all amino acids
