Structure and Function of DNA

Structure &

Function of DNA

Today I will: Identify components of DNA, explain how the nucleotide sequence specifies

some traits of an organism, and examine scientific explanations for the origin of DNA

Prokaryotes vs. Eukaryotes

Every cell contains genetic material in the form of DNA.

In prokaryotic cells, the DNA is contained within a singular,

circular chromosome and exposed to the rest of the cell.

Multiple Choice

Where is DNA located in prokaryotic cells?

• the nucleus

• linear outside of the cell

• in a circular chromosome, free-floating in the cytoplasm

• no where

Prokaryotes vs. Eukaryotes

In eukaryotes, the nucleus contains the genetic material

of the cell, also in the form of DNA.

While only eukaryotes keep their DNA in a nucleus, it is

important to understand that every cell uses DNA.

Nucleus

Eu = Do

Contains a nucleus and

membrane bound organelles

Prokaryotes Eukaryotes

Pro = No

Nucleus or membrane

bound organelles

Multiple Choice

Do prokaryotic cells have a nucleus?

• Yes

• No

Multiple Choice

Do eukaryotic cells have a nucleus?

• Yes

• No

DNA stands for DeoxyriboNucleic Acid

A nucleic acid is a long repeating chain of nucleotides.

Multiple Choice

What are the subunits (materials) that make up a nucleic acid called?

• nucleotides

• amino acids

• sugars

• fats

Nucleic Acids

Every nucleotide has 3basic parts:

1

2

3

The phosphate group

2.

A deoxyribose sugar

3.

One of the 4 nitrogenous bases

Labelling

Label the parts of the nucleic acid

Drag labels to their correct position on the image

phosphate group

a nitrogenous base

deoxyribose sugar

Nitrogen Bases

The 4 nitrogen bases in DNA are:

A

Adenine

T

Thymine

G

Guanine

C

Cytosine

Why do you think they are called the nitrogen bases?

Because they all contain the element nitrogen!

Multiple Choice

What element do all the nitrogen bases contain?

• sulfur

• nitrogen

• helium

• phosphorous

DNA Structure

Two chains of nucleic acids join together to form a

double-stranded molecule of DNA.

These two strands spiral around one another to create a

shape that scientists call a double helix.

DNA Structure

The outside of the DNA is called the sugar-phosphate backbone.

This gives the DNA its shape and structure.

DNA Structure

The nitrogen bases are on the inside of the double helix.

This is how the information is coded in the DNA.

Multiple Choice

Where is the INFORMATION in a DNA molecule stored?

• double helix

• the inside, with the nitrogen bases

• outside, with the backbone

The Biggest Genome

The information in DNA is a blueprint for every cell. The
information is found in the sequence of nitrogen bases.

This information is used to make proteins according to a

universal genetic code.

Genetic Code

Every cell uses the information in DNA to make proteins in the same

way.

The DNA is translated using the genetic code where a specific

sequence of nitrogen bases codes for an amino acid in the protein being

made.

All living things use the SAME

genetic code!

Multiple Choice

What does the sequence of nitrogen bases in DNA code for?

• nothing

• carbohydrates

• proteins

• lipids

The Genetic Code is common to all…

From the fish in the sea,

To the mold on the wall!

Multiple Choice

Do all living organisms use the same genetic code?

• Yes, the genetic code is common to all

• No

Chromosomes

DNA is not found in many little pieces. Instead, large amounts of

DNA are packaged together into chromosomes.

Human cells hold 46 chromosomes that contain thousands of genes.

Multiple Choice

What is DNA packaged as inside the body?

• nothing, its just long DNA strands

• carbohydrates

• enzymes

• Chromosomes

Genes are the sections of DNA that are used to

make proteins in the cell.

DNA

RNA

Protein

Multiple Choice

What are the genes in your DNA?

• sections of DNA used to make proteins

• another word for DNA

• they don't exist

• used to make carbohydrates

DNA Base Pairing

The nitrogen bases between the two strands of DNA pair

together in a very specific way.

A pairs with T
C pairs with G

How can you remember which

letters pair together?

Apples in the Tree

Cars in the Garage

Drag and Drop

Fill in the acronym used to remember how DNA base pairs match up:

​ ​

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in the ​

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​

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in the ​

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Drag these tiles and drop them in the correct blank above

Apples

Tree

Cars

Garage