DNA STRUCTURE

Question 1

What does DNA stand for?

Answer 1

Deoxyribonucleic Acid

DNA is the molecule that carries genetic information in living organisms.

Question 2

What are the three components of a nucleotide?

Answer 2

• Phosphate Group
• Sugar
• Nitrogenous Base

Nucleotides are the building blocks of DNA.

Question 3

The sugar component in DNA is called deoxyribose. What type of sugar is it?

Answer 3

Five-carbon sugar

Deoxyribose is a modified form of ribose that lacks one oxygen atom.

Question 4

True or false: The structure of DNA can be described as a twisted ladder.

Answer 4

TRUE

The two strands of DNA serve as the sides of the ladder, while the rungs are formed by pairs of nucleotides.

Question 5

What are the two categories of nitrogenous bases in DNA?

Answer 5

• Purines
• Pyrimidines

Purines include adenine and guanine; pyrimidines include thymine and cytosine.

Question 6

Fill in the blank: Adenine pairs with _______ in DNA.

Answer 6

thymine

This is part of the base pairing rules that govern DNA structure.

Question 7

What is the function of phosphate groups in DNA?

Answer 7

Characterizes nucleic acids as acids

Phosphate groups contribute to the acidic properties of DNA when in solution.

Question 8

What is the carbon numbering of the sugar component in DNA?

Answer 8

• 1’ Carbon: bonded to nitrogenous base
• 2’ Carbon: lacks oxygen
• 3’ Carbon: attaches to next nucleotide
• 4’ Carbon: forms cyclic structure
• 5’ Carbon: attached to phosphate group

This numbering is crucial for understanding the structure and function of DNA.

Question 9

What type of bond forms between nitrogenous bases in DNA?

Answer 9

Hydrogen bonds

These bonds involve attractions between partial charges on electronegative atoms.

Question 10

What is the specific nitrogenous base found in RNA instead of thymine?

Answer 10

Uracil

Uracil replaces thymine in RNA, which is a key difference between DNA and RNA.

Question 11

Summarize the components of a nucleotide.

Answer 11

• Phosphate group
• Deoxyribose sugar
• Nitrogenous base

These components combine to form the structure of DNA.