BIOL 1202 Lecture : Biology 1202 Notes (entire Year)
4/2/2012 5:17:00 AM
People=Homo sapiens (species)
• Same species but diff.=genetics
• Genes+environment
• How do you know if they are the same speicies? Make them
reproduce
Biological species concept=two individuals in a population mate in nature,
they produce vial offspring then they are the same species
• Ex. dogs mate with other dogs, cats mate with other cats
• Cats and dogs cannot mate=diff. species
• Exceptions=liger
• If species are separated for long enough, they will become diff.
species
o Ex. great dane kept from lab, they may become separate
species
Homo sapiens=wise man
• eukaryote
E. coli=prokaryote (single cell)
• E. coli living in colon cause production of vitamins
o E. coli and you both benefit from relationship
• Parasite=does well and benefits but harms you
• E. coli=small bacteria
• Binary fision=bacteria produce by dividing
Cell theory=every single living cell on this planet come from preexisting cells
• Single cell went through mitosis to produce many cells which make
up you
• Human cells go through mitosis
• 1st cell of human is the diploid cell (egg and sperm)
• meiosis occurred in testes to make the sperm from one of the
diploid cells
• everything on this planet originated from the same single cell
• DNA sequence tells whether your more related to someone than to
someone else if it is more similar
• Humans share more DNA sequence similarity to chimpanzees and
bonobos
• Living species in the world today were not there millions of years
ago
100 million species of life separated into 3 domains of life
• eukarya
• bacteria
• archaea
Earth is 4.6 billion years old
1st earliest life is dated about 4.2 billion years ago
How is life first presented on Earth?
At one point Earth was lifeless
Charles Darwin-evolution→How did life become so diverse and vary?
A,T,G,C
All living things use DNA as genome
Prokaryotic or eukaryotic to be considered a living thing
All living things use transcription=DNA→RNA
Translation=RNA (AUG starting codon)→protein
The Evolution of Homer J. Simpson-Youtube Video
Archaea and bacteria are diff. bc they have differences in genetic codes,
membrane stuctures, and chromosomes but they are both prokaryotes
Gene Expression and Regulation
Mutations can be good and can be bad or no difference in organisms
Genes can be turned on or off
• Can be lowly expressed or highly turned on
How do we go from genes to physical structure?
• Genes determine protein structure
• Protein structure determines the way the processes of life are
carried out
• all about making proteins
o enzymes are proteins that catalyze chemical reactions
▪ speed up chemical reactions
o sequence of amino acids
• DNA used to make RNA which is used to make proteins
o DNA→RNA→Proteins
o Gene=segment of DNA located at a particular place on a
chromosome
o Alleles=dominant or recessive
o Can only have 2 copies of each specific locus (allele)
o DNA codes for specific A.A. sequence in a protein or for the
RNA that helps make proteins
▪ If you change the sequence, enzyme may be used in
diff way or may not work
DNA vs RNA (from table 10-1)
• DNA
o Double stranded
o Deoxyribose
• RNA
o Single stranded (can be found in double stranded but if found
in humans it is destroyed)
o Ribose
o Messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA
(rRNA)
▪ Equally important to make protein
Same genes everywhere in your body but some may be turned on or
expressed (transferred to RNA) some may be turned off
How is info in a gene transcribed into RNA?
• Transcription: 1st 2 steps (fig. 10-4a b)
• RNA polymerase (protein that catalyzes a reaction)
• Initiation=occurs when RNA polymerase binds to DNA
• Elongation=RNA polymerase slides down DNA producing RNA
• Termination=RNA polymerase detaches from DNA and RNA stops
production
How is the sequence of a mRNA molecule translated into proteins?
• 4 nucleotides (A,U,G,C)
• 20 amino acids=have to be coded for (3 nucleotides)
• genetic code=AUG (initiation codon)
• Codon
o Triplet of nucleotides
o Codes for one specific amino acid
