Transcript Lesson Overview - Pottsgrove School District

Lesson Overview
12.1 Identifying the
Substance of Genes
Lesson Overview
Identifying the Substance of Genes
Griffith’s Experiments
Griffith isolated
different strains of bacteria.
Only one caused pneumonia.
Lesson Overview
Identifying the Substance of Genes
Griffith’s Experiments
When injecting mice with
mice
.
When injecting mice with
stayed
.
bacteria, the
bacteria, the mice
Lesson Overview
Identifying the Substance of Genes
Griffith’s Experiments
First, Griffith took the
,
injected the them into mice.
Mice
produce.
them, and then
, showing that it wasn’t a toxin the bacteria
Identifying the Substance of Genes
Lesson Overview
Griffith’s Experiments
In Griffith’s next experiment, he mixed the
S-strain
with
R strain and injected the mixture into mice.
The mice
.
Lesson Overview
Identifying the Substance of Genes
Transformation
Process called
- one type of bacteria is changed into
another.
Because transformed bacteria inherited ability to cause disease,
Griffith concluded the transforming factor was a
.
Lesson Overview
Identifying the Substance of Genes
The Molecular Cause of Transformation
Avery
proteins, lipids, carbohydrates, and RNA.
Transformation still
.
Lesson Overview
Identifying the Substance of Genes
The Molecular Cause of Transformation
Then destroyed
and transformation did
Therefore, DNA was the transforming factor.
Meant that DNA stores and transmits genetic
.
occur.
Lesson Overview
Identifying the Substance of Genes
Bacteriophages
- virus that infects bacteria
Lesson Overview
Identifying the Substance of Genes
The Hershey-Chase Experiment
Hershey and Chase studied a bacteriophage with a DNA core and a
protein coat.
Wanted to determine if the protein or DNA changed bacteria
Hershey and Chase grew viruses containing P-32 and S-35
Lesson Overview
Identifying the Substance of Genes
The Hershey-Chase Experiment
Bacteria contained P-32 , found in
.
Hershey and Chase confirmed Avery’s results - that
genetic material found in
.
was the
Lesson Overview
Identifying the Substance of Genes
The Role of DNA
DNA can
, copy, and
genetic information
Lesson Overview
12.2 The Structure of DNA
Lesson Overview
Identifying the Substance of Genes
Nucleic Acids and Nucleotides
Located in
Made up of
.
.
Three components: a 5-carbon sugar called
group, and a
base.
,a
Lesson Overview
Identifying the Substance of Genes
Nucleic Acids and Nucleotides
DNA has four nitrogenous bases: adenine, guanine, cytosine,
and thymine, or
.
Lesson Overview
Identifying the Substance of Genes
Chargaff’s Rules
Chargaff discovered the amount of
[A] and [T] bases are almost
.
The same is true for guanine [G]
and cytosine [C].
and
“Chargaff’s rules.”
is known as
Lesson Overview
Identifying the Substance of Genes
Franklin’s X-Rays
Rosalind Franklin used X-ray
diffraction that showed:
- DNA has
twisted
around each other.
- The nitrogen bases are near
the
.
Lesson Overview
Identifying the Substance of Genes
The Work of Watson and Crick
Franklin’s X-ray pattern enabled
Watson and Crick to build a
model of DNA.
Built 3-D model of DNA in a
.
Lesson Overview
Identifying the Substance of Genes
Antiparallel Strands
DNA strands are “antiparallel”— they run
in
directions.
Lets nitrogenous bases join at center and
allows each strand to carry nucleotides.
Lesson Overview
Identifying the Substance of Genes
Hydrogen Bonding
bonds form between bases
and hold strands together.
Hydrogen bonds are weak and allow
strands to
.
Lesson Overview
Identifying the Substance of Genes
Base Pairing
Fit between A–T and G–C
nucleotides called
.
EUKARYOTIC DNA REPLICATION
Step 1 –
unzips the DNA molecule.
Step 2 – DNA
adds on complementary nucleotides.
Step 3 – The
strand replicates in
of continually like the
strand.
Leading Strand
Lagging Strand
instead
OKAZAKI FRAGMENTS
Step 4 –Enzyme
strand.
joins the fragments on lagging
Step 5 – As replication continues, the strands
helix.
into
_
Are the tips of chromosomes make sure genes aren’t lost
during replication.
PROKARYOTIC DNA REPLICATION
Starts at
point,
and goes in 2
directions until the
chromosome is
copied.
PROKARYOTIC VS. EUKARYOTIC
DNA Replication Process [3D Animation] – Biology / Medicine Animations HD
https://www.youtube.com/watch?v=27TxKoFU2Nw
Lesson Overview
Fermentation
Lesson Overview
13.1 RNA
Lesson Overview
Fermentation
The Role of RNA
First step - copy
.
RNA, like DNA, is a nucleic acid made
of nucleotides.
RNA uses the base sequence copied
from DNA to make
.
Lesson Overview
Fermentation
Comparing RNA and DNA
Each nucleotide in both DNA and RNA is made up of a
5-carbon sugar, a phosphate group, and a nitrogenous
base.
Three differences between RNA and DNA:
(1) Sugar in RNA is
(2) RNA is
(3) RNA contains
.
-stranded.
instead of thymine (T).
Lesson Overview
Fermentation
Comparing RNA and DNA
The cell uses DNA “master plan” to prepare RNA
“blueprints.”
DNA stays in
, while RNA goes to
.
Lesson Overview
Fermentation
Functions of RNA
RNA is like a disposable copy of a
segment of DNA, a working copy of a
single gene.
RNA assembes
.
into
Lesson Overview
Fermentation
Functions of RNA
Three main types of RNA:
RNA,
RNA, and
RNA.
Lesson Overview
Fermentation
Messenger RNA
The RNA molecules that
instructions are known as
messenger RNA (
)
_
Lesson Overview
Fermentation
Ribosomal RNA
Ribosomal RNA (
.
) make up
Lesson Overview
Fermentation
Transfer RNA
Transfer RNA (
) transfers
to the ribosome
Lesson Overview
Fermentation
Making RNA - Transcription
– Turning
into
.
Lesson Overview
Fermentation
Transcription
In prokaryotes, RNA and
protein synthesis occurs in the
.
In eukaryotes, RNA is produced
in the
and moves to the
to produce proteins.
Lesson Overview
Fermentation
Transcription
Requires RNA polymerase, which
assemble complementary strand of
DNA strands to
.
Lesson Overview
Fermentation
Promoters
RNA polymerase binds to
.
Promoters show RNA
polymerase where to
RNA.
Similar signals cause
transcription to
making
.
Lesson Overview
Fermentation
RNA Editing
Parts of RNA are cut out and stay
the nucleus are called
.
The remaining pieces, known as
, are joined together into the
final mRNA, which
the nucleus.
Lesson Overview
Ribosomes and Protein Synthesis
Lesson Overview
13.2 Ribosomes and
Protein Synthesis
Lesson Overview
Ribosomes and Protein Synthesis
The Genetic Code
First step -
DNA to RNA.
Contains code for making proteins.
The genetic code is read
“base
letters” at a time and corresponds to a
single
.
Lesson Overview
Ribosomes and Protein Synthesis
The Genetic Code
Proteins are made by joining amino acids together into long
chains, called
.
There are about
amino acids.
Lesson Overview
Ribosomes and Protein Synthesis
The Genetic Code
The type and
determine the
of amino acids
of proteins.
Order of amino acids affects the
of the protein, which determines
its
.
Lesson Overview
Ribosomes and Protein Synthesis
The Genetic Code
Each three-letter “word” in mRNA is known as a
A codon specifies a single
.
.
Lesson Overview
Ribosomes and Protein Synthesis
Start and Stop Codons
The “
” codon AUG
begins protein synthesis.
Then mRNA is read, three bases
at a time, until it reaches a
“
” codon, which ends
translation.
Lesson Overview
Ribosomes and Protein Synthesis
Translation
The decoding of
translation.
is called
Lesson Overview
Ribosomes and Protein Synthesis
Steps in Translation
mRNA is
the
in the
.
and then
in
Lesson Overview
Ribosomes and Protein Synthesis
Steps in Translation
Translation begins when a
ribosome attaches to mRNA.
As the ribosome reads mRNA,
it directs
to
amino
acid.
Lesson Overview
Ribosomes and Protein Synthesis
Steps in Translation
Each tRNA molecule carries
amino acid.
Each tRNA has three unpaired
bases, called the
—
which compliment one mRNA
.
Lesson Overview
Ribosomes and Protein Synthesis
Steps in Translation
bonds form between amino
acids
At the same time, the bond holding
tRNA to its amino acid is
.
Lesson Overview
Ribosomes and Protein Synthesis
Steps in Translation
The polypeptide chain grows until
the ribosome reaches a “
”
codon, which
translation.
Lesson Overview
Ribosomes and Protein Synthesis
The Roles of tRNA and rRNA in
Translation
holds
proteins in place.
Lesson Overview
Ribosomes and Protein Synthesis
The Molecular Basis of Heredity
contain
for assembling proteins.
Lesson Overview
Ribosomes and Protein Synthesis
The Molecular Basis of Heredity
- the way DNA, RNA, and proteins put genetic
information into
in living cells.
Lesson Overview
Ribosomes and Protein Synthesis
The Molecular Basis of Heredity
There is a
nature in the genetic code.
Although some organisms show slight variations in the amino acids
assigned to particular codons, the code is always read three bases
at a time and in the same direction.
Despite their enormous diversity in form and function, living
organisms display remarkable
at life’s most basic level, the
molecular biology of the gene.
Lesson Overview
Ribosomes and Protein Synthesis
Lesson Overview
13.3 Mutations
Lesson Overview
Ribosomes and Protein Synthesis
Types of Mutations
Cells can make mistakes, called
.
Lesson Overview
Ribosomes and Protein Synthesis
Types of Mutations
All mutations fall into two basic
categories:
mutations - changes in a
single gene
mutations - changes in
whole chromosomes.
Lesson Overview
Ribosomes and Protein Synthesis
Gene Mutations
mutations - changes
in one or a few nucleotides.
Changes can be
on to
every cell that develops from
the original one.
Lesson Overview
Ribosomes and Protein Synthesis
Gene Mutations
Point mutations include
.
Lesson Overview
Ribosomes and Protein Synthesis
Substitutions
In a substitution, one base is
Usually affect a
amino acid
to a different base.
Lesson Overview
Ribosomes and Protein Synthesis
Insertions and Deletions
Insertions and deletions are mutations in which one base is
.
Called
mutations because they shift the “reading
frame” of the genetic message.
Lesson Overview
Ribosomes and Protein Synthesis
Chromosomal Mutations
Chromosomal mutations involve changes in the
of chromosomes.
Four types:
, duplication,
or
, and translocation.
Lesson Overview
Ribosomes and Protein Synthesis
Chromosomal Mutations
Deletion involves the
of all or part of a chromosome.
Lesson Overview
Ribosomes and Protein Synthesis
Chromosomal Mutations
Duplication produces an
chromosome.
of all or part of a
Lesson Overview
Ribosomes and Protein Synthesis
Chromosomal Mutations
Inversion
the direction of parts of a chromosome.
Lesson Overview
Ribosomes and Protein Synthesis
Chromosomal Mutations
Translocation occurs when part of one chromosome
and
to another.
off
Lesson Overview
Ribosomes and Protein Synthesis
Effects of Mutations
Genetic material can be altered by
natural or artificial means.
Resulting mutations may or may not
affect an organism, most do not.
Some mutations that affect individual
organisms can also affect a species or
even an entire ecosystem.
Lesson Overview
Ribosomes and Protein Synthesis
Effects of Mutations
Many mutations are produced by
in genetic processes.
An incorrect base is inserted
roughly once in every
bases.
Small changes can
time.
over
Lesson Overview
Mutagens
Ribosomes and Protein Synthesis
Some mutations arise from
- chemical or
physical
in the
environment.
Chemical mutagens include
certain pesticides, plant alkaloids,
tobacco smoke, and
environmental pollutants.
Physical mutagens include forms
of electromagnetic radiation, such
as X-rays and UV light.
can
also be a factor.
Lesson Overview
Ribosomes and Protein Synthesis
Harmful Effects
The most harmful mutations dramatically change protein
or gene
.
Example: Sickle Cell Disease
Lesson Overview
Ribosomes and Protein Synthesis
Beneficial Effects
Some mutations can be highly
species.
to an organism or
Example: Pesticide Resistance and Polyploidy