DNA Structure Lesson 1

20 Question and Answer flashcards covering DNA structure, components, and base pairing rules based on the provided lecture notes.

What does DNA stand for?

Deoxyribonucleic acid

What is the primary function of DNA in cells?

It acts like a book of code that tells your cells what to do.

Where is DNA primarily located within a cell?

Inside the nucleus.

What is the distinctive shape of a DNA molecule?

A double helix, similar to a twisted ladder.

What are the basic building blocks of a DNA molecule?

Nucleotides.

What are the three components that make up a nucleotide?

A phosphate group, a deoxyribose sugar molecule, and a nitrogen base.

Name the four different nitrogenous bases found in DNA.

Adenine, Guanine, Thymine, and Cytosine.

What two molecular components form the 'backbone' of the DNA molecule?

Phosphate groups and deoxyribose sugar molecules.

What are the two distinct ends of a DNA strand called, indicating the orientation of the phosphate and sugar links?

The 5' (five prime) end and the 3' (three prime) end.

Which nitrogenous base always pairs with Adenine in DNA, and by how many hydrogen bonds?

Thymine, by two hydrogen bonds.

Which nitrogenous base always pairs with Cytosine in DNA, and by how many hydrogen bonds?

Guanine, by three hydrogen bonds.

What rule governs the pairing of nitrogenous bases between the two sides of the DNA backbone?

A purine must bond to a pyrimidine.

Which two nitrogenous bases are classified as purines?

Adenine and Guanine.

Which two nitrogenous bases are classified as pyrimidines?

Thymine and Cytosine.

What crucial information is encoded by the specific sequence of base pairs in DNA?

The genetic code.

What is an interesting fact about the total length of DNA if unraveled from a human body?

It would stretch from the Earth to the Sun hundreds of times.

What sugar molecule is a key component of a DNA nucleotide?

Deoxyribose sugar.

Inside the nucleus, DNA is tightly coiled into what structures?

Chromosomes.

What is a structural characteristic of purine bases like Adenine and Guanine?

They have two carbon-nitrogen ring structures.

What is a structural characteristic of pyrimidine bases like Thymine and Cytosine?

They have one carbon-nitrogen ring structure.