Nucleic Acids

DNA & RNA

What are the two nucleic acids?

• RNA

• DNA

What does DNA stand for?

Deoxyribonucleic acid.

What is the function of DNA?

DNA stores genetic information that controls the cells structure and function by coding for proteins.

Where is DNA found in cells?

• The Nucleus

• The Mitochondria

• Chloroplasts (in plant cells)

What is a chromosome?

A long thread-like structure made up of DNA wrapped around proteins called histones.

What is a gene?

A short segment of a DNA molecule that codes for a particular protein.

Who discovered the structure of DNA?

• James Watson

• Francis Crick

Whose work helped Watson and Crick discover DNA’s structure?

Rosalind Franklin’s X-ray images of DNA provided cruical information.

What was the significance of their discovery?

They discovered that DNA has a double helix structure, which explains how genetic information is stored and copied.

What is the shape of DNA?

A double helix

Two strands twisted around each other (optional)

What are the monomers of DNA?

Nucleotides

What are the three parts of a nucleotide of a DNA molecule?

• Deoxyribose sugar

• Phosphate group

• Nitrogenous base

Name the four nitrogenous bases in DNA?

• Adenine

• Thymine

• Guanine

• Cytosine

Which nitrogenous bases pair together in DNA?

• Adenine and Thymine

• Cytosine and Guanine

What is DNA replication?

The process where DNA makes an exact copy of itself before cell division.

When does DNA replication occur?

During Interphase of the cell cycle.

Why is DNA replication so important?

To ensure each daughter cell contains the same genetic information as the mother cell.

What is the first step of DNA replication?

The DNA double helix unwinds and the strands seperate.

Two identical threads called ___ are formed during DNA replication.

Chromatids

Chromatids are joined by what?

A centromere

Where is RNA found in the cell?

In the nucleus and the cytoplasm.

What is the structure of RNA?

Single stranded

What sugar is found in RNA?

Ribose Sugar

What are the nitrogenous bases in RNA?

• Adenine

• Uracil

• Cytosine

• Guanine

What are the three types of RNA?

• Messenger RNA (mRNA)

• Transfer RNA (tRNA)

• Ribosomal RNA (rRNA)

What is the function of mRNA?

It carries the genetic information from DNA to the ribosomes.

What is the function of tRNA?

It brings amino acids to the ribosomes during protein synthesis.

What is the function of rRNA?

It forms part of the ribosomes and helps with protein synthesis.

What are the four differences between RNA and DNA?

DNA	RNA
Double Helix	Single stranded
Deoxyribose sugar	Ribose sugar
Thymine	Uracil
Equal number of nitrogenous bases.	Occur in any sequence or ratio.