DNA Structure and Function

​Title: DNA Structure and Function

​EQ: What is the structure of DNA and how does that help the function?

​What is DNA?

• Stores genetic information

• Chromosomes and genes

• Our blueprints

Multiple Choice

What is the function of DNA?

• store energy

• build things

• stores genetic information

• powers our brain

​What is the relationship between DNA, chromosomes, and genes?

• The cell contains the nucleus

• The nucleus contains chromosomes

• Chromosomes are made up of DNA

• DNA is made up of genes

Multiple Choice

Which is the smallest?

• Nucleus

• DNA

• Chromosome

• Gene

​The structure of DNA

​The DNA molecule consists of two strands that wind around one another to form a shape we call the double helix.

Each strand is made up of:
- phosphate/sugar "backbone"
-nitrogenous bases
- monomer = nucleotide

​A DNA nucleotide is composed of 3 parts:
1. Phosphate
2. Sugar
3. Nitrogenous Base

The four bases are:
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)

​DRAW THIS:

Multiple Select

Select the 3 parts of a nucleotide.

• phosphate

• sugar

• gene

• nitrogenous base

​Complementary Strands

​The two strands of DNA are complementary to one another.

Rules of pairing:
A - T
Apples in the trees
C - G
Cars in the garages

Multiple Choice

Adenine (A) pairs with....

• A

• T

• C

• G

Multiple Choice

Cytosine (C) pairs with....

• A

• T

• C

• G

Multiple Choice

If I have AATGCA, the complementary strand will be...

• TTACGT

• GGATGT

• ATGCAT

• CCATAC

​DNA Replication

​What is DNA replication?
DNA replication is the process where a copy of DNA is made.

Why would DNA need to replicate?
To make new cells and the new cell must have the same DNA as the old cell.

​DNA Replication Steps

​Step 1: DNA unzips, exposing the base pairs.
Step 2: DNA polymerase creates new complementary strand of DNA by using the base pairs as the template.
Step 3: The DNA zips itself back up and the new DNA is complete.

Multiple Choice

Which step is second?

• DNA polymerase creates a new strand

• DNA unzips

• DNA zips itself back up

Multiple Choice

Which step is first?

• DNA polymerase creates a new strand

• DNA unzips

• DNA zips itself back up

Multiple Choice

Which step is last?

• DNA unzips

• DNA zips itself back up

• DNA polymerase creates a new strand