Protein%20Synthesis%20(transcription%20and%20translation),%20Genetics,%20and%20Evolution

1
CBA Review

• Protein Synthesis (transcription and
  translation), Genetics, and Evolution

2
Protein Synthesis
3
DNA vs. RNA
DNA RNA
Double stranded Deoxyribose sugar Guanine, cytosine, adenine, thymine (G-C), (A-T) Stays in nucleus Single-stranded Ribose sugar Guanine, cytosine, adenine, uracil (G-C), (A-U) mRNA moves from nucleus to cytoplasm, tRNA and rRNA (ribosomes) stay in cytoplsam.
4
TRANSCRIPTION!

• mRNA
• copies DNA in nucleus
• takes copied gene to cytoplasm
• Attaches to RIBOSOME (rRNA)
• Made up of three letter triplets called CODONS
• DNA Strand
• AGG-GAC-TAT-GAT-AGC
• Complimentary RNA Strand
• UCC-CUG-AUA-CUA-UCG

5
(No Transcript)
6
TRANSLATION!

• tRNA
• Reads the mRNA each CODON at a time
• Has the opposite of the codon, called the
  ANTI-CODON, which matches using base-pairing
  rules (A-U), (G-C)
• Translation happens in the CYTOPLASM within
  RIBOSOMES.

7
(No Transcript)
8
tRNA ANTI-CODON
mRNA CODON
9
Amino Acids

• Monomers of proteins
• Every codon codes for an amino acid
• DNA Strand
• ATA-CGG-ACC-TAA-GAG
• mRNA Strand
• Write on white board
• Amino Acid Sequence
• Write on white board

10
(No Transcript)
11
GENETICS!

• Gene Regulation
• Mendelian Genetics
• Principle of Dominance
• Monohybrid and dihybrid crosses
• Non-Mendelian Genetics
• Incomplete Dominance
• Codominance
• Polygenic Traits
• X-Linked Traits
• Gene Technology
• Recombinant DNA
• DNA Fingerprinting
• Karyotyping
• Pedigrees
• Chromosomal Mutations
• Meiosis

12
Gene Regulation

• Remember Oxana Malaya, the girl who was raised by
  dogs
• When she was born, she was completely normal,
  mentally and physically
• She now experiences difficulties learning and
  with language and lives in assisted living. Why?

13
Gene Regulation

• The environment influences gene expression.
• Genes
• Expressed transcription CAN happen
• Not expressed transcription CANNOT happen
• Prokaryotes (Bacteria)
• LAC Operon set of genes that make the enzymes
  that digest lactose
• No lactose present genes NOT expressed (Turned
  off)
• Lactose present genes EXPRESSED (turned on

14
Gene Regulation

• Eukaryotes
• Use transcription factors
• More complex process than in prokaryotes
• Epigenome the marker proteins that turn genes
  on and off

15
Mendelian Genetics

• Monohybrid Crosses
• Letters on the sides of the Punnett square are
  GAMETES (Law of Segregation)
• Dihybrid Crosses
• RrYy x RrYy
• Will always end up with a 9331 phenotypic
  ratio
• FOIL to find gametes (Law of Independent
  Assortment)

16
Non-Mendelian Genetics

• Incomplete Dominance heterogygotes have
  blended appearance (If RR Red, and WW
  White, then RW Pink)
• Codominance BOTH traits are expressed equally in
  heterozygotes (COWdominance if BB black cow
  and WW white cow, then BW black and white
  spotted cow)

17
(No Transcript)
18
Non-Mendelian Genetics (cont.)

• X-Linked Traits
• Carried on the X-Chromosome
• Females are XX, males are XY, so males CANNOT be
  heterozygous for X-linked traits
• Polygenic Traits
• More than one set of alleles for the trait
• You see a bell-curve distribution of phenotypes
  with these traits
• Ex- hair color, height, skin tone, etc

19
Gene Technology

• Recombinant DNA genes inserted into PLASMIDS of
  bacteria to trick the bacteria into making the
  proteins that are desired
• Ex Insulin for people with diabetes

20
Gene Technology

• DNA fingerprinting
• Everyone has different DNA fingerprints EXCEPT
  IDENTICAL TWINS!
• Used in paternity tests and crime scenes

21
Gene Technology

• Karyotyping
• Used to detect chromosomal abnormalities
• Can be performed while a woman is pregnant to
  detect abnormalities in the fetus amniocentesis
• NON-DISJUNCTION mutations cause TRISOMIES!

Trisomy 21 Down Syndrome Caused by
NON-DISJUNCTION mutation
22
Pedigrees

• DARKENED individuals are AFFECTED
• If you see half-colored circles or squares, the
  individual is a CARRIER
• Not all carriers are half-colored.

23
Chromosomal Mutations
24
Meiosis VS Mitosis
25
Meiosis VS Mitosis

• Meiosis 2n ? 1n
• Diploid cells to haploid cells
• Makes GAMETES (eggs and sperm)
• Mitosis 2n ? 2n
• Diploid cells to diploid cells

26
Non-Disjunction Mutations

• Cause a TRISOMY on a karyotype
• Chromosomes dont separate during meiosis

27
Evolution

• Endosymbiotic Theory
• Origin of Complex Molecules
• Evidence of Evolution
• Fossils
• Homologous, Vestigial structures
• Embryology
• DNA evidence
• Mechanisms of Evolution
• Natural selection, mutation, migration (gene
  flow), genetic drift (bottlenecking,
  founder-effect)
• Directional, Disruptive, Stabilizing selection
• Convergent vs Divergent Evolution

28
Endosymbiotic Theory

• Mirochondria and Chloroplasts used to be bacteria!

29
Origin of Complex Molecules

• Oparin Haldane hypothesized that amino acids
  could form in the early Earths environment
• Miller Urey tested it..and it worked!

AMINO ACIDS formed after a week!
30
Iron-Sulfur World Hypothesis

• Discovery of ecosystems based on chemosynthesis
  in deep hydrothermal vents offered support
• Chemosynthesis making glucose using inorganic
  molecules instead of sunlight as a catalyst
• Catalysts in this instance Iron (Fe) and Sulfur
  (S)

31
RNA World Hypothesis

• RNA came before DNA because CATALYTIC RNA is
  SELF-REPLICATING.
• Catalytic RNA needs no proteins to aid in the
  process of replication, unlike DNA
• Catalytic RNA acts like an enzyme, but it is not
• RNA nucleic acid, enzymes proteins

32
Fossils

• Older fossils are in lower layers
• Newer fossils are in top layers
• When fossils disappear from
• one layer to another, the organisms
• must have gone extinct

33
Gradualism vs Punctuated Equilibrium
Gradualism
Punctuated equilibrium
34
Gradualism

• TRANSITION FOSSILS

35
Punctuated Equilibrium

• NO transition fossils

36
Punctuated Equilibrium
37
Homologous Structures

• Similar because of common ancestry
• DIVERGENT EVOLUTION

38
Analogous Structures

• Independent evolutionno common ancestry
• CONVERGENT EVOLUTION

39
Vestigial Structures

• Not used in modern species evidence of ancestry
• Ex- leg bones in whales, appendix in humans

40
Molecular Evidence

• More DNA in
• common more
• closely related
• DNA similarities
• Amino Acid similarities

41
Embryology

• All vertebrates go through similar embryonic
  stages early in development
• Tails become backbones

42
Adaptive Radiation

• Divergent Evolution
• An ancestral species diversifies into many
  different species
• Ex- mammals after dinosaur extinction

43
(No Transcript)
44
Hardy-Weinberg Equilibrium

• When no evolution is happening
• Random mating
• No environmental pressures
• Does not exist in real life

45
Convergent vs Divergent

• CONVERGENT

• DIVERGENT

• UNRELATED species adapt to similar environments
• Produces ANALOGOUS sturctures

• RELATED species become more different
• Produces HOMOLOUS structures

46
Types of Natural Selection
47
Cladograms
48
(No Transcript)
49
(No Transcript)
50
(No Transcript)