Unit 4 - DNA and RNA

Unit 4 -

DNA and RNA

Nucleic Acid Review

Nucleic Acid is one of the 4 biomolecules. Nucleic acid has two polymers: DNA and RNA. DNA and RNA are made up of monomers called nucleotides (monomers). Nucleotides contain the elements CHONP (carbon, hydrogen, oxygen, nitrogen, and phosphorus). 

Nucleotide

A nucleotide, the monomer of nucleic acid, is made up of 3 parts:

1. Phosphate group
2. 5-carbon sugar
3. Nitrogen base

Multiple Choice

What is the monomer of a Nucleic Acid?

• DNA

• RNA

• Nucleotide

• Fatty Acid

Nucleotide

There are 4 different types of nitrogen bases in DNA:

1. A = Adenine
2. T = Thymine
3. C = Cytosine
4. G = Guanine

Scientists that Discovered the Structure of DNA

James Watson and Francis Crick earned the Nobel Prize for building a model to show the structure of DNA.

Scientists that Discovered the Structure of DNA

Rosalind Franklin used x-rays to take special pictures that revealed DNA to have a double helix structure. Watson and Crick could not have built their DNA model without the important information from Rosalind Franklin’s x-ray pictures.

Multiple Choice

What was Watson and Crick's main scientific accomplishment?

• Building the first accurate model of DNA
• Isolating strains of pneumonia causing bacteria
• Determining base pairing rules
• Discovering the process of genetic transformation

Multiple Choice

Who is responsible for producing this image?

• Francis Crick
• James Watson
• Rosalind Franklin
• Watson and Crick

DNA

DNA, or Deoxyribonucleic Acid, contains the genetic information we pass on from one generation to the next.

The overall structure of the polymer DNA is called a double helix, “double” because it contains 2 strands of nucleotides, and “helix” because it is twisted into a spiral shape.

DNA Structure

The double helix of DNA is like a twisted ladder. The ladder is made of 2 strands of nucleotides. The sugars and phosphates make up the “sugar-phosphate backbones”, or the outsides of the ladder. The nitrogen bases make up the rungs (steps) of the ladder. The two sides of the ladder are connected down the middle by many hydrogen bonds.

Multiple Choice

What are the three components of a nucleotide?

• sugar, hydrogen, nitrogen base
• sugar, oxygen, nitrogen base
• sugar, phosphate, nitrogen base
• sugar, phosphate, protein

Multiple Choice

Which 2 molecules form the sides (backbone) of the DNA ladder?

• deoxyribose sugar and adenine
• deoxyribose sugar and a hydrogen bond
• deoxyribose sugar and the nucleus
• deoxyribose sugar and phosphate

Multiple Choice

Which of the following units are repeatedly joined together to form a strand of DNA?

• amino acids
• nucleotides
• fatty acids
• polysaccharides

Multiple Choice

Which of the following best describes a DNA molecule?

• double helix
• contains ribose
• made of amino acids
• contains Uracil

Base Pairing Rules

To connect the two strands of DNA, the nitrogen bases must match up in a specific way: A always pairs with T, and C always pairs with G.

A and T are complementary to each other, and C and G are complementary to each other. Complementary means they fit together, or pair together.

Base Pairing Rules

For example, if a sequence of DNA reads "ATCGA", then it's complementary sequence would be "TAGCA".

So,

ATCGA

TAGCT

This is because A is complementary with T and C is complementary with G.

Multiple Choice

Which sequence of DNA bases would pair with: ATC

• ATC

• TAG

• CCC

• GAT

Multiple Choice

Which sequence of DNA bases would pair with this partial strand
ATG TGA CAG

• ATG TGA CAG
• TAC ACT GTC
• GTA AGT GAC
• CAT TCA CTG

Chromosome

Our human cells contain about 3 meters of DNA in the nucleus. To fit so much DNA into such a tiny space, the DNA coils up very tightly into chromosomes. Each of our chromosomes contains a very large amount of DNA.

Gene

A gene is a specific sequence of nucleotides found in our DNA that contains instructions to make a protein. Each of our chromosomes contains many genes. The difference between two different genes is the sequence of nitrogen bases it contains.

RNA

RNA, ribonucleic acid, is the other polymer of nucleic acid. It is similar to DNA it is important in making protein, it is made of monomers called nucleotides, and it contains the elements CHONP (carbon, hydrogen, oxygen, nitrogen, and phosphorus). However, instead of having 2 strands like DNA, RNA has only one strand and it contains the nitrogen base Uracil in place of Thymine. 

Multiple Choice

What is the difference between DNA and RNA in terms of bases?

• RNA contains uracil in place of thymine
• RNA contains uracil in place of adenine
• RNA contains uracil in place of guanine
• RNA contains uracil in place of  cytosine

Multiple Choice

Which of the following statements is true?

• DNA is single-stranded
• RNA is single-stranded
• DNA contains uracil
• RNA contains deoxyribose

Multiple Choice

RNA contains the sugar

• ribose
• deoxyribose
• glucose
• lactose

Multiple Choice

The following picture must be

• DNA because it's double stranded
• RNA because it's single stranded
• DNA because it's single stranded
• RNA because it's double stranded

Why is DNA important?

DNA is important because it contains the instructions for making all the proteins in your body. These protein-coding instructions are known as our genetic code, or genetic information.

Why is DNA important?

The genetic code is made up of different sequences of nucleotides. Difference sequences of nucleotides carry information on how to make different proteins, and these different proteins are responsible for our many different traits, such as hair color and eye color.

Why is DNA important?

Proteins are responsible for many important jobs in our cells (like enzymes) and make up much of the structure of our bodies. Proteins are necessary for normal growth and function of organisms and cells.

Who has DNA?

All Living things on earth has DNA. Bacteria, animals, plants, fungi, and protists all contain genetic information in the form of DNA.

All DNA is made of the same building blocks, or nucleotides so, sometimes we even have similar genes that contain instructions on how to make similar proteins that do the same jobs in our cells. 

Who has DNA?

This means we can compare DNA between two different species, and it also allows scientists to combine DNA from two different species, because the nucleotides and structure are the same.

Open Ended

In your own words, explain why DNA and RNA are important in cellular functions?