DNA and RNA
Nucleic Acids
Mrs. Dignan’s Science Class
Nucleic Acids
Nucleic acids are found in the nucleus (only
in eukaryotes)
 DNA and RNA are the 2 major nucleic acids
 DNA=Deoxyribo nucleic acid
 RNA=Ribo nucleic Acid
 The “job” of nucleic acids is to make
proteins
 Nucleic acids contain C,H,O,N and P

DNA
DNA is stored safely in
the nucleus (in
eukaryotes). It can’t leave
the nucleus.
 DNA can be a very long
molecule

 DNA
from a single human
cell would extend for
almost 2 meters if you
stretched it out.

DNA has a double helix
structure.
Nucleotides

DNA is made out of long
chains of nucleotides
 There
are 4 types of
nucleotides, distinguished
by the base they contain:
 Adenine, Thymine,
Cytosine, and Guanine.
(A, T, C, G)
 A’s only bond with T’s,
and C’s only bond with G’s

“Apples grow on Trees, but
Carrots grow in the Ground.”
ADENINE – THYMINE
CYTOSINE - GUANINE
A DNA Nucleotide
Phosphate
Group
O
O=P-O
O
5
CH2
O
N
C1
C4
Sugar
(deoxyribose)
C3
C2
Nitrogenous base
(A, G, C, or T)
DNA Double Helix
5
O
3
3
P
5
O
O
C
G
1
P
5
3
2
4
4
2
3
P
1
T
5
A
3
P
O
O
P
5
O
3
5
P
Genetic Diversity…

Different
arrangements of
NUCLEOTIDES in
DNA provide the
key to diversity
among living
organisms.
The Code of Life…
The “code” of the
DNA is the
SPECIFIC ORDER
that bases occur.
 Different orders
produce different
proteins
 Different proteins
make different
physical features
 A section of DNA
that produces a
specific protein is
called a “gene”

 T---?
 C---?
 T---?
 G---?
 A---?
 A---?
 C---?
 T---?
 G---?
 A---?
 C---?
 G---?
Create the
complimentary
strand for this
single DNA strand
 T---A
 C---G
 T---?
 G---?
 A---?
 A---?
 C---?
 T---?
 G---?
 A---?
 C---?
 G---?
Just to get you
started…
 T---A
 C---G
 T---A
 G---C
 A---T
 A---T
 C---G
 T---A
 G---C
 A---T
 C---G
 G---C
There is only one
correct
complimentary strand
for the single DNA
strand
Now we have one
molecule of
double stranded
DNA
DNA Replication
DNA can be copied so that a cell will have
multiple DNA codes and can divide into 2
cells.
 Before Replication an enzyme called
helicase “unzips” the double stranded DNA
molecule into 2 single strands.
 Then an enzyme called DNA polymerase
adds nucleotides to both strands until we
have 2 identical DNA strands.

DNA Replication
DNA replication video
 Advanced DNA Replication Video

 T---A
 C---G
 T---A
 G---C
 A---T
 A---T
 C---G
 T---A
 G---C
 A---T
 C---G
 G---C
Replicate the DNA
molecule at Left
RNA
RNA can go into the
nucleus and out of the
nucleus
 RNA is a copy of DNA
 RNA is only made of 1
strand
 RNA is also made of 4
nucleotides, but it has
Uracil instead of Thymine.
 A, U, C, G
 “Trees get Uprooted”

RNA Transcription
Transcription is the process of producing
RNA from DNA.
 Transcription is like DNA replication but
the molecule made is RNA (instead of
DNA) and it is single stranded.
 Also the DNA molecule used remains the
same after transcription.
 The Enzyme that makes RNA is called RNA
polymerase.

RNA Transcription
RNA Transcription Video
 Advanced Transcription Video

 T---?
 C---?
 T---?
 G---?
 A---?
 A---?
 C---?
 T---?
 G---?
 A---?
 C---?
 G---?
Create the RNA
copy of this DNA
strand
 T---A
 C---G
 T---A
 G---?
 A---?
 A---?
 C---?
 T---?
 G---?
 A---?
 C---?
 G---?
Just to get you
started…
 T---A
 C---G
 T---A
 G---C
 A---U
 A---U
 C---G
 T---A
 G---C
 A---U
 C---G
 G---C
There is only one
correct RNA copy
Now we have
TRANSCIBED the
DNA into RNA
Protein synthesis in 2 easy steps!

Step 1: Transcription
 The
DNA is copied to make RNA
 “Transcription”

means to make a copy
Step 2 Translation
 The
RNA goes to a ribosome and starts
making proteins
 “Translation”
means to turn one thing into
another, like translating Spanish into English
Protein Synthesis
Exit Task

Add to your venn diagram comparing and
contrasting DNA and RNA. Identify at
least 3 additional differences between
DNA and RNA.
DNA
RNA