Transcript p. synthesis

PROTEIN SYNTHESIS
TRANSCRIPTION: DNA m RNA
TRANSLATION: m RNA Protein
Summary of Events in Protein Synthesis
TRANSCRIPTION
Transcription: A Deep look
A. RNA is made from the DNA nucleotide
sequence during transcription.
1. __________________attaches to the
beginning of one gene or a group of
genes, called the ___________, on
the
DNA molecule.
2. DNA separates at
the______________________
3. half the DNA serves as a template
to make RNA from nucleotides
a. base sequence in DNA
determines the base sequence in
the RNA molecule
4. transcription ends at the
________________________________
______on the DNA molecule
a. indicates the end of a
___________or a
group of genes
5. m-RNA, t-RNA and r-RNA may be
made
Transcription
http://www.biostudio.com/d_%20Transcript
ion.htm
http://www.stolaf.edu/people/giannini/flash
animat/molgenetics/transcription.swf
FIND MORE WEBSITES…
TRANSLATION
Translation- in ribosomes
_________makes proteins with the help of
_____________.
The ___________on the mRNA dictate
the amino acids that the tRNA brings to
the ribosome.
The ________________ on the tRNA
hooks up with the CODON and the a.a. is
brought to the appropriate location.
Translation starts at the start codon (AUG)
and ends at the stop codon (UGA, UAG,
UAA)
Chain of amino acid= protein
B.
B. How is the sequence of amino acids
determined in translation?
1.codon (3-base sequence on m-RNA)
a. 64 codons- code for amino acids
2. start codon (AUG) starts translation
a. it codes for the methionine
3. codons on m-RNA pair with
anticodons on t-RNA
4. stop codons (UAA, UAG, UGA) stop
translation
Codon Chart
Start and Stop Codons on RNA
Stop Codon Animation
Peptide Bond Formation
PROTEIN SYNTHESIS
SUMMARY
Transcription - DNA makes RNA
Translation – t-RNA anticodons line
up with m-RNA codons at the
ribosome
peptide bonds connect amino acids
in dehydration synthesis
the GENETIC CODE is the correlation
between DNA base sequence and
amino acid sequence in a
polypeptide
TRANSLATION
Work on the building of Protein at the following
website
http://www.pbs.org/wgbh/aso/tryit/dna/
http://www.brookscole.com/chemistry_d/templates
/student_resources/shared_resources/animations/
protein_synthesis/protein_synthesis.html
http://www.brooklyn.cuny.edu/bc/ahp/BioInfo/SD.T
ransTrans.HP.html
http://learn.genetics.utah.edu/content/begin/dna/transc
ribe/
http://www.biostudio.com/demo_freeman_protein_synt
hesis.htm (w the ribosome subunits)
http://www.brookscole.com/chemistry_d/templates/stu
dent_resources/shared_resources/animations/protein_
synthesis/protein_synthesis.html
http://learn.genetics.utah.edu/units/basics/transcribe/ (
actual do it yourself protein)
http://www.cst.cmich.edu/users/Benja1dw/BIO101/tool
s/quiz/dnarna.htm
GENES ARE SEGMENTS OF DNA
THAT CODE FOR A
CHARACTERISTIC, LIKE DIMPLES.
REALLY ITS
_______________________________I
N THE DNA DETERMINE THE
CHARACTERISTIC. BUT
SOMETIMES PROBLEMS ARISE….
Mutations
A. Location of Mutations
1. _____________(body cell)
2. _________cell (cells that form sperm
and egg cells)
B. Causes
1. radiation
a. x-rays, alpha, beta, gamma
radiation, u.v. light
2. chemicals (mutagens)
3. DNA sequence changes in replication
C. Effects of Mutations
1.__________(deadly)
2. may be beneficial
3. no effect
Point Mutation
change in one nucleotide …or change in a
base (A,T,C,G) in the DNA molecule
Types of mutations –
a. ___________ – one base
is
substituted for another
b. _____________– an extra
base is added
c. __________ or deletion of
a base
Point Mutation:
Substitution of One Base
BIGGER PROBLEMS…
WHEN ONE OR TWO BASES ARE
ADDED/DELETED, EVEN BIGGER PROBLEMS
ARISE BECAUSE DNA IS “READ”
IN________________SEQUENCES.
TRANSLATION? EVERY 3 DNA BASES CODE
FOR AN AMINO ACID (REMEMBER THE
BUILDING BLOCK OF PROTIENS) AND YOU
KNOW THAT PROTEINS ARE EVERYWHERE IN
OUR BODIES!
TO UNDERSTAND WHY, WE NEED TO
UNDERSTAND HOW PROTEINS ARE FORMED.
When things go wrong…
Frameshift – results when the number
of nucleotides inserted or deleted is
not a multiple of three
1. addition or deletion can result
in a _______________
2. results in a completely different
sequence of amino acids in the
polypeptide chain
Frameshift
Frameshift- Insertion
CELL CYCLE CONTROL BY
PROTEINS
What happens when the cell cycle proteins
are the ones being mutated?
 Loss of Control of the Cell Cycle
 if checkpoints are not working
properly, the cell cycle can cause the
cell to grow
uncontrollably
 leads
to _________
http://outreach.
mcb.harvard.e
du/animations
_S03.htm
How does variation get passed on?
REPRODUCTION!!!!
Knowing DNA stores the message for all
characteristics, how does it get passed on?
______________________
Types of reproduction
– Asexual (Mitosis)- which produces identical
offspring (e.g. budding, binary fission)
– Sexual (Meiosis)- which produces egg and
sperm.
Heredity- How genetic traits are passed from
one generation to another
ASEXUAL REPRODUCTION
(MITOSIS) IS ONLY 1 WAY
ORGANISMS (SIMPLE)
REPRODUCE! THERE ARE
SOME ADVANTAGES
(____________), BUT A
HUGE DISADVANTAGE- NO
___________IN
OFFSPRING!!!
Sexual vs Asexual Reproduction
Asexual
Sexual
One parent
__________geneti
c material
Mitosis, budding,
binary fission
Two parents
Different genetic
material
Meiosis +
______________
What is Meiosis Exactly?
Meiosis is a form of cell division that halves
the number of chromosomes when forming
specialized reproductive cells such as
gametes or spores
2 CELL DIVISIONS: Meiosis 1 and meiosis 2
CREATE 4__________cells (1N) only 1 copy
of the chromosomes.
MITOSIS VS. MEIOSIS
Mitosis- process that happens during 1) growth 2)
asexual reproduction 3) repair of cells 4)regeneration
AFTER 4 STAGES (P-M-A-T) and 1 cell division IT
PRODUCES 2 CELLS IDENTICAL (_____________)
TO THE PARENT CELL- SAME DNA
VS.
Meiosis- process that happens to make sex cells (egg
and sperm)
AFTER ____ STAGES (PMAT-P2M2A2T2) and 2 cell
divisions, IT PRODUCES_____CELLS WITH
DIFFERENT GENETIC INFO FROM PARENT
REMEMBER CHROMOSOMES
THEY ARE DNA STRANDS WRAPPED AROUND
HISTONE PROTEINS.
IN ALL _______________THEY COME IN PAIRS
(2N) CALLED THE ______________ NUMBER.
ONE OF THE PAIR IS FROM MOM/DAD.
– We have 46 chromosomes in body cells- 23 pairs.
SINCE IN SEX CELLS THERE NEEDS TO BE ½
THE # OF CHROMOSOMES, THEY ARE NO
LONGER IN PAIRS…THEY ARE ALONE. THIS
IS CALLED THE _____________ (HALF)
NUMBER (1N)
– We have 23 chromosomes in egg/sperm.
Stages of Meiosis 1
Stages of Meiosis 2
S phase of Interphase
(Before Replication- Mitosis)
Interphase after replication
I. Meiosis (Reduction Division)
A. Meiosis I
1. __________________
a. chromosomes become distinct
b. nucleolus and nuclear membrane
disappear and spindle fibers appear
Prophase I
c. spindle fibers appear
d.____________–homologous
chromosomes
Line up together form ____________
(group of 4)
Prophase I
e. ____________________may occur
1) portions of chromatid from one
parent break off and attach to a
homologous chromatid from the
other parent
2) results in ______________________________
2. _____________________
a. chromosomes line up along the
midline
b. sister chromatids do not separate
3. ____________________
a. at random, one member of each
homologous pair moves to the
opposite poles
(_______________________________
)
4. _________________and Cytokinesis
I
a. chromosomes reach opposite
poles
b. cytokinesis begins
Telophase I
c. resulting cells have the n
or______________number of
chromosomes
1) one member of each
homologous pair with two attached
chromatids
d. each new cell contains ½ the
the number of chromosomes as
the original cell
B. Meiosis II
1. ___________________
a. spindle form and chromosomes
begin to move toward the mid-line
of
the cell
. ____________________
a. chromosomes move to the midline of the dividing cell
3. _____________________
a. chromatids separate and move to
the opposite poles of the cell
4. ______________________
a. nuclear membrane forms around
the nucleus in each cell
b. each resulting cell contains the
n number of chromosomes
Meiosis 1 and Meiosis 2
Chart Comparing Mitosis and Meiosis
Mitosis
2 cells result
One division
2n number of
chromosomes in
resulting cells
Daughter cells
are identical
Meiosis
4 cells result
Two divisions
n number of
chromosomes in
resulting cells
Daughter cells
are all different
E. Formation of Gametes
1. ___________________ – results in 4
viable sperm
2. _______________ – results in 1 egg
and
3 polar bodies
Spermatogenesis
Oogenesis
Fertilization [sperm (n) + egg (n)  zytote
(2n) ]
Sexual vs Asexual Reproduction
Asexual
Sexual
One parent
Identical genetic
material
Mitosis, budding,
binary fission
Two parents
Different genetic
material
Meiosis +
fertilization
WHEN THINGS GO WRONG!
_____________________
1. Down’s Syndrome
(extra 21)
2. Patau’s Syndrome
(extra 13)
3. Edward’s Syndrome (extra 18)
4. Klinefelter’s Syndrome (XXY)
5. Turner’s Syndrome
(XO)
Nondisjunction occurs when homologous
chromosomes do not segregate in meiosis I
or sister chromatids do not separate in
meiosis II (causes __________ and
monosomy)
Other Chromosome Mutations……..
1. Deletion – piece of chromosome
is deleted or
_____________ – piece of a
chromosome
is duplicated
2. Inversion – segment of a chromosome
is inverted
Chromosome Mutation - Duplication
Chromosome Mutations
Deletion and Duplication
3. Translocation –
pieces of non homologous
chromosomes are exchanged
How would it affect evolution if there
was no genetic variation through
mutation or crossing over of genes?
23
23
23
46
23
23
23
REPRODUCTION AND HEREDITY
HOW GENES ARE PASSED ON!!
I. Gregor Mendel (1822-1884)
A. Background
1. entered monastery at 21
2. studied math and science
at University of Vienna
3. 1857-1865 – investigated
inheritance in pea plants
Gregor Mendel
The Monastery
B. Peas – A Fortunate Choice
(Pisum sagivum)
1. distinct characteristics
(flower color, flower position,
seed color, seed texture, height)
2. easy to grow
3. mature quickly
4. easy to pollinate
D. Mendel’s Experiments
1. P1 Generation (Parental)
a. crossed plants pure for a trait
2. F1 Generation (Offspring of P1)
a. all plants show one form of
the trait
3. F2 Generation (Offspring of F1)
a. show forms of trait in 3:1
ratio
Mendel’s P, F1and F2 Generations
Examples of P1 Cross
Tall X Short
(both are pure)
TT X tt
All offspring are tall (T t) F1 Generation
F1 Generation (all are ___________)
Purple Flower X White Flower (both pure)
PP X pp
All ___________ are purple (Pp) F1
Generation
F1 Generation (all are hybrids)
Mendel’s F1 Cross (hybrid x hybrid)
Tall X Tall (hybrid cross)
Tt X Tt
3 tall plants : 1 short plant (F2 Generation)
Ratio of 3:1
Purple Flowers X Purple Flowers (hybrid)
Pp X Pp
3 purple flower plants : 1 white flower (F2)
Ratio of _________
E. Analysis of Mendel’s Results
1. traits controlled by a pair of factors
a. today factors are called alleles
2. Principle of ________________
a. one factor (gene) can prevent
expression of another (dominance)
3. Law of ___________________
a. a pair of factors separate when
gametes form (during meiosis)
4. Law of
_______________________________
a. factors (genes) for different
characteristics separate
independently …
(just b/c you have blonde hair doesn’t
mean you’ll have blue eyes)
II. Vocabulary
A. Genotype
1. genetic makeup
2. examples
a. TT, Tt, tt,
b. __________________
B. Phenotype
1. external appearance
2. examples
a. tall, short
b. purple flowers, white flowers
C. Homozygous (pure)
1. two alleles code for the same trait
2. examples
a. TT, tt, PP, pp
D. Heterozygous (hybrid)
1. two alleles do not code for the
same trait
2. examples
a. ________________
E. Dominant (represented by upper
case letter)
1. allele that masks the recessive
allele for the same characteristic
F. Recessive (represented by lower
case letter)
1. allele that is masked by the
dominant allele for the same
characteristic
III. Complete Dominance
(Monohybrid Cross)
A. Both parents are pure
1. homozygous x homozygous
2. example T T x t t
B. Both parents are hybrid
1. heterozygous X heterozygous
2. example Tt x Tt
III. Complete Dominance
C. Pure parent X hybrid parent
1.homozygous dominant X heterozygous
a. Example T T x T t
2.homozygous recessive x heterozygous
a. Example tt x Tt
IV. Incomplete Dominance
(both alleles influence the trait)
A. Pure X Pure = all hybrids
1.example (red flower and white flower)
a. RR x WW
B. Hybrid X Hybrid
1. example (pink x pink flower)
a. RW x RW
C. Pure X hybrid
1.example (red x pink or white x pink)
a. RR x RW or WW x RW
Incomplete Dominance Four O’clock
Flowers
Pink (RW)
White (WW) Red
(RR)
V. Codominance
(both alleles are expressed)
A. Pure X Pure
1. example (white horse x red horse)
a. WW x RR
B. Hybrid x Hybrid
1. example (roan horse x roan horse)
a. RW x RW
C. Pure X Hybrid
1. example(red x roan or white x roan)
a. RR x RW or WW x RW
VI. Dihybrid Cross
(two traits considered)
A. Homozygous X homozygous
1. all offspring are heterozygous for
both traits (all are hybrids)
B. Heterozygous X heterozygous
1. 4 phenotypes possible
2. phenotype ratio 9:3:3:1
Dihybrid Cross
VII. Test Cross
A. Purpose
1. to help determine the genotype
of an organism
B. Procedure
1. cross individual with unknown
genotype with individual with
homozygous recessive individual
2. example T t x tt or T T x tt
VIII. Multiple Allele Problems (Blood
Types)
A. PHENOTYPE
Type A
B. GENOTYPE
AA, AO ( IA IA , IA i )
Type B
BB, BO ( IB IB , IB i )
Type AB
AB
( IA IB )
Type O
OO
( ii )
Blood Donors and Recipients
World Distribution of the A Allele
World Distribution of the B Allele
World Distribution of Type O Blood
VIII. Multiple Allele Problems
Blood Types
C. One parent has type AB blood and one
has
type O. What blood types are possible in
the
offspring?
D. One parent has type A blood and one
has
type B blood, what are the possible blood
IX. Polygenic inheritance of Traits
A. Influenced by several genes
1. often show much variation
B. Examples
1. hair color, eye color, skin color
2. height
3. foot size, nose length
Frequency Distribution of a Polygenic
Trait
X.
Sex-linked Inheritance
(X linked-carried on X
chromosome)
A. Examples of sex-linked traits
1. color blindness
2. _____________
3. muscular dystrophy
4. Icthyosis
Individual
Chromosomes
Normal Male
Male with Disease
XY
X* Y
Normal Female
Female Carrier
Female - Disease
X X
X* X
X* X*
Problem Solving- Sex Linked Diseases
A. A man is colorblind and his wife is a
carrier
for colorblindness. What is the probability
that
they will have a child who is colorblind?
(A son? A daughter?)
B. A man and woman are both colorblind.
Can
XI.Sex-influenced Inheritance
(Baldness)
Normal Male
Bald Male
bb
Bb, BB
Normal Female
Female Carrier
Bald Female
bb
Bb
BB
Sex-influenced Inheritance–Problem
Solving
A. If a man is bald and his wife carries a gene
for baldness, what is the chance of his son
being bald? (His daughter?)
B. If a man is not bald but his wife carries a
gene for baldness, can his son be bald?
(His daughter?)
Pedigree-a genetic family tree
http://genetics.gsk.com/graphics/autosomal_recessive.gif
h
tt
:
Pedigree chart tells us two things
– 1. WHETHER IT IS AN AUTOSOMAL(22 BODY
PAIRS) OR SEX-LINKED (1PAIR OF SEX TRAITS
XX OR XY) If male and female is close to equal it is
autosomal
– 2. WHETHER IT IS DOM. OR RECESS. TRAIT- IF
THE TRAIT IS PASSED TO NEXT GENERATION –
BUT SKIPPED A GENERATION IT IS RECESSIVEIF THE PARENTS WERE NORMAL AND HAD A
CHILD WITH THE TRAIT IT IS RECESSIVE
Autosomal pedigree chart
Sex-linked pedigree
XII. Genetic Diseases - Examples
XII. GENETIC DISEASES
A. Dominant Single Allele
1.
2.
3.
4.
Huntingtons
Dwarfism
Cataracts
Polydactyl
GENETIC DISEASES
B. Recessive Single Allele
1. Albinism
2. PKU (phenylketonuria)
3. Deafness
4. Sickle Cell Anemia
5. Cystic Fibrosis
6. Tay Sachs
GENETICS DISEASES
C. X-Linked
1. Colorblindness
2. Hemophilia
3. Muscular Dystrophy
4. Icthyosis
Genetic Diseases – Linked Genes
Linked Genes and Genetic Diseases
Inheritance of Recessive
Genetic Diseases
Inheritance of Genetic Diseases
Normal Red Blood Cells
and Sickle Cells
D. Sex-Linked Genetic Diseases
X-Linked (Diseases on X chromosome)
Hemophilia Inheritance
Sex-Linked Genetic Disease
SO WHERE THE VARIATION
EVOLUTION ACTS UPON COME
FROM???
Variation in Populations
C. Genetic Sources of Variation
1. Mutations
a) a specific gene mutates in
1/10,0000 gametes
b) thousands of genes in each gamete
c) some mutations in every zygote
d) most mutations are recessive
IV. Variation in Populations
C. Genetic Sources of Variation
2. Genetic Recombination
a) random meeting of sperm and egg
b) crossing over
c) independent assortment
What can decrease variation in a population?
1. Genetic Drift
a) occurs in small populations
b) elimination of some genes by chance
c) may decrease variation
IV. Variation in Populations
C. Genetic Sources of Variation
2. Non-random Mating
3. Fecundity selection/ Mortality selection
Some organisms with certain traits reproduce more or survive better to
reproductive age than others.
What can increase variation in a population?
1. Migration (Gene Flow)- mating with members of different
populations).
a) immigration- movement into an
area or population
b) emigration – movement out of an
area or population
2. Random mating
H-W Equilibrium
The Hardy-Weinberg law of genetic
equilibrium provides a mathematical model
for studying evolutionary changes in allelic
frequency within a population. A
population in Hardy-Weinberg
equilibrium shows no change.
ANIMATION
http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/life4e_15-6-OSU.swf
IV. Variation in Populations
D. Genetic Equilibrium
1. Hardy-Weinberg Principle
a) allele frequencies are stable across generations
b) sexual reproduction alone does not
affect genetic equilibrium
2. Conditions Necessary
a) no immigration
c) no natural selection
e) random mating
b) no mutations
d) large populations
f) everyone produces the same number
of offspring
CONCEPTS OF H-W EQUILBRIUM
http://www.phschool.com/science/biology_place/labbench/lab8/conce
pts.html
IV. Variation in Populations
E. Mathematics/Hardy Weinberg
1. gene pool - all the genes in a population
2. allele frequency - % occurrence of a
specific allele in a population
3. phenotype frequency - % occurrence of
an individual in a population with a trait
4. genotype frequency - % occurrence of
individuals in a population with a specific
genotype
IV. Variation in Populations
E. Mathematics/Hardy Weinberg
5. applying mathematics
a) p = frequency of the dominant allele
q = frequency of the recessive allele
b) p + q = 1
c) p2 + 2pq + q2 = 1
IV. Variation in Populations
E. Mathematics/Hardy Weinberg
d) q2 = recessive phenotype/genotype
frequency
p2 +2pq = dominant phenotype
frequency
p2 = pure dominant genotype frequency
2pq= heterozygous genotype frequency
Problems:
In a population of 100 cats, 84 are black
and 16 are white.
What is the phenotype frequency for white
cats? Black cats?
What is the recessive allele frequency?
What is the dominant frequency?
HW problem
Given an allele frequency for the tall allele
(T=.60), calculate the phenotype
frequencies for tall and short plants.
Short phenotype frequency?
Tall phenotype frequency?
More problems…
If 4.0% of seeds are yellow and 96% are
green (Green is dominant). Calculate the
allele frequencies for the yellow allele and
the allele for green.
Yellow allele frequency?
Green allele frequency?
Even more problems….
25% of an animal population has blue
eyes (recessive) and 75% have brown
eyes. What is the allele frequency for the
blue (b) allele and for the brown (B) allele?
Recessive allele frequency?
Dominant allele frequency?
Evolution Revisited…
1. Evolution may be defined as
a) change in genetic material in a
population
b) change in allele frequency in a
population
c) change in genotype/phenotype ratio
d) speciation
SUMMARY
THE ENVIRONMENT DRIVES
EVOLUTION TO FAVOR CERTAIN
VARIATIONS OF ORGANISMS (no one
best way to be all the time). THESE
VARIATIONS ARISE FROM MUTATIONS
AND MEIOSIS AND GET PASSED ON
THROUGH REPRODUCTION AND
HEREDITY.