Outcome: Model the structure of Nucleic acids. Compare and contrast DNA and RNA.

Warm up:

1. Name the building blocks of carbohydrates, lipids and proteins.

2. Differentiate the structure of protein.

3. What are the building blocks of enzymes.

4. What are the 3 parts of an amino acid? How many amino acids are there?

NUCLEIC ACIDS

Used To:

• Store Genetic Info

• Translate Genetic Info

Building Blocks = Nucleotides

Examples: DNA

RNA

Nucleic Acid

Picture:

Nucleic Acids What are nucleic acids?

The cells information storage molecules

• There are two types of nucleic acids

DNA, deoxyribonucleic acid

RNA, ribonucleic acid

• These ‘work together’ to synthesize protein

DNA

• DNA stands for deoxyribonucleic acid

• Building blocks: nucleotides

Synthesizing Protein

It carries instructions for building all the proteins

What does DNA do?

Information in DNA is transcribed into RNA

What does DNA do?

RNA acts as an intermediary in the protein-making process

What does RNA do?

DNA

RNA

Protein

What else does RNA do?

RNA then translates the (transcribed) information into the primary structure of proteins

What is the primary structure of proteins?

Structure What is the structure of nucleic acids?

They are polymers of nucleotides

Phosphate group

What do the nucleotides contain?

Sugar

Nitrogen base

(Deoxyribose)

Structure of a nucleotide • Sugar (deoxyribose or ribose)

• A Phosphate group

• One of four of the nitrogen containing bases.

Nitrogen Bases

Purines

Adenine (A)

Guanine (G)

Pyramidines

Cytosine (C)

Thymine(T)

What do DNA nucleotides contain?

Each DNA nucleotide has one of the following bases:

Adenine (A)

Guanine (G)

Thymine (T)

Cytosine (C)

1 2

3 4

Which one is which?

Match the numbers to the base

Polymers of nucleotides

Linked into long chains

Called polynucleotides or DNA strands

A sugar-phosphate backbone joins them together

Nucleotide

Bases

Activity: Nucleic Acid Structure

2 DNA strands form helix

How does this happen?

Via complementary binding

C always binds with G

A always binds with T

(and hydrogen bonding)

Base Pairing – Chargaff’s Rule Adenine pairs with or is complementary to Thymine

Cytosine pairs with or is complementary to Guanine

DNA STRUCTURE

•CONNECTED WITH WEAK BONDS

DNA STRUCTURE

•How many bases?

•How many base pairs?

WHAT ARE THE SUBUNITS OF DNA?

NUCLEOTIDES

WHAT ARE THE SUBUNITS OF DNA?

• PHOSPHATE

• DEOXYRIBOSE SUGAR

DNA LOOKS LIKE A LADDER

BONDS IN DNA

COVALENT BONDS (STRONG)

HYDROGEN BONDS (WEAK)

RNA, different from DNA

The RNA sugar has 2 OH groups vs 1 in DNA

It has the base uracil (U) instead of thymine (T) in DNA

(Ribose vs deoxyribose)

3 Types of RNA

• mRNA – messenger – carries DNA’s message out of the nucleus and to the ribosome.

• rRNA – ribosomal – at the ribosome.

• tRNA – transfer – carries the amino acid and transfers it to the protein chain.