Download DNA and RNA

DNA and RNA
DNA
Questions:
What are the
monomers called
that DNA is made
of?
What are the three
components of
DNA?
What sugar is DNA
made of?
What are the 4
nucleotides of DNA?


Made of nucleotides – which are
made of
 5 carbon sugar - deoxyribose
 Phosphate group
 Nitrogenous base
There are 4 nitrogen bases
 Adenine
 Guanine
 Cytosine
 Thymine
DNA Arrangement
Questions:
What is the shape
of DNA?
Who discovered the
shape of DNA?
Describe how DNA
is configured?

Looks like a twisted latter –
called double helix
 Discovered


Watson and Crick
The sides are made of sugar
and phosphate that alternate
Each rung is made of 2
nitrogenous bases
 Adenine
and thymine
 Cytosine and guanine
DNA Replication

Questions:
Explain the steps of
DNA replication?
What is the result of
DNA replication?
How does the why
DNA replicates
help conserve
genetic
information?

DNA has 2 complementary sides
To replicate:
 An enzyme called DNA helicase splits
DNA down the middle
 It begins at a point called the
replication fork
 It separate in both directions
 As it separates into 2 sides complementary bases (in the nucleus)
attach to each side using DNA
polymerase
 This results in two identical pieces
of DNA – each with 1 original and 1
new strand
SC.912.L.16.3 Describe the basic process of DNA replication and how it relates to the transmission and
conservation of genetic information.
RNA

Questions:

What is RNA?
How is the RNA
similar and
different from the
DNA molecule?


RNA – Is slightly different
It is only a single strand
Its nucleotide made of:
 5 carbon sugar ribose
 Phosphate group
 Nitrogenous bases
Contains the nitrogen bases:
 Adenine
 Guanine
 Cytosine
 Uracil
Types of RNA
Questions:
What are the three
types of RNA
and what is the
job of each?

There are three types of
RNA – all help to make
proteins
 Messenger
RNA – contain
instructions
 Ribosomal RNA – assembles
the protein
 Transfer RNA – transfers amino
acids to the ribosomes
Types of RNA
Making RNA
Questions:
What is the process
of making RNA
called?
Explain the steps of
making RNA.


RNA is made by copying part of DNA
 Called transcription
Steps
 RNA polymerase separates the
DNA at a specific location
 RNA nitrogen bases attach to one
of the strands of DNA (uracil
instead of thymine)
 The piece of RNA separated from
the DNA
SC.912.L.16.5 Explain the basic processes of transcription and translation, and how they result in the expression
of genes.
RNA Editing
Questions:
Why does RNA
need to be
edited?
What are the parts
called that are
removed and
kept?
What type of RNA
is made in the
end?
 Editing
must happen before
RNA leaves the nucleus
 Gets rid of unneeded pieces
called introns
 Keeps the parts called exons
 The exons bond together to
make mRNA
 The mRNA leaves the nucleus
to go to the ribosomes
SC.912.L.16.5 Explain the basic processes of transcription and translation, and how they result in the expression
of genes.
Removing Introns
Making Proteins
Questions:
What is the
process of
making
proteins
called?
What is a codon
and where is it
found?
How and why is
the genetic
code universal
to most
organisms?



Process is called translation
Made by joining amino acids into long
chains called polypeptides
 Sequence of the amino acids determines
the protein
The steps:
 mRNA is sent to the ribosome
 mRNA reads 3 letters at a time (these 3
letters are called codon)
 Each codon represents a single
amino acid (AUG=Start)
 These codons represent the universal
genetic code
SC.912.L.16.5 Explain the basic processes of transcription and translation, and how they result in the expression
of genes.
SC.912.19.9 Explain how and why the genetic code is universal and is common to almost all organisms.
Codons and Their Corresponding
Amino Acid
Translation - Continued
Questions:
Explain the steps of
protein
translation?
(remember the
previous slide)






The mRNA sends for a tRNA that has
the complementary nucleotides (called
anticodon) that they are needed
The tRNA brings a specific amino
acids to the ribosome
The amino acid the tRNA carries is
bonded to the polypeptide chain
The tRNA is released from the mRNA
and leaves to get another amino acid
This continues until a stop codon is
reached
Then the polypeptide (protein) is
released and goes where it is needed
SC.912.L.16.5 Explain the basic processes of transcription and translation, and how they result in the expression
of genes.
Protein Synthesis – Part 1
Protein Synthesis – part 2
Mutations
Questions:
What is a
mutation?
What is a gene
mutation?
What types of
gene mutations
are there and
what are some
examples?


Mutation – change in the genetic material
Types:
 Gene mutations – mistakes in a specific
gene
 Can be frame shift
Insertion – when a nitrogenous base
is added
 Deletion – when a nitrogenous base
is removed


Non- frame shift

Substitution – one nitrogenous base
is wrong - causes a different the
amino acid
SC.912.L.16.4 Explain how mutations in the DNA sequence may or may not result in phenotypic change. Explain how mutations in
gametes may result in phenotypic changes in the offspring.
SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agent to health from the
perspective of both the individual and public health.

Questions:
What are
chromosomal
mutations?
Explain the
differences
between the
types of
mutations?
Chromosomal mutations – changes
in the structure of the chromosome
 There are 4 types:
 Deletion – part of chromosome
is missing
 Duplication – part of the
chromosome is repeated
 Inversion – part of the
chromosome is flipped over
 Translocation – part of the
chromosome is removed from
one chromosome and attached
to another
SC.912.L.16.4 Explain how mutations in the DNA sequence may or may not result in phenotypic change. Explain how mutations
in gametes may result in phenotypic changes in the offspring.
SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agent to health from the
perspective of both the individual and public health.
Chromosomal mutations
Effects of Mutations
Questions:
Explain how
different
mutations can
effect an
organism?



Some are neutral –
 a single letter change may still give
the same amino acid
Some are harmful –
 May change protein structures or
gene activity
 Cause disorders or mutations
Some are helpful –
 cause variations that all the
organism to survive its environment
(extra fur, color change)
SC.912.L.16.4 Explain how mutations in the DNA sequence may or may not result in phenotypic change. Explain how mutations
in gametes may result in phenotypic changes in the offspring.
SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agent to health from the
perspective of both the individual and public health.