Podcast
Questions and Answers
What is the shape of the DNA molecule?
What is the shape of the DNA molecule?
Adenine (A) pairs with Cytosine (C) according to Chargaff's rule.
Adenine (A) pairs with Cytosine (C) according to Chargaff's rule.
False
What is the role of DNA in a cell?
What is the role of DNA in a cell?
Controls all activities of the cell
DNA stands for ______.
DNA stands for ______.
Signup and view all the answers
Match the nitrogenous bases with their complementary pairs:
Match the nitrogenous bases with their complementary pairs:
Signup and view all the answers
Which component is NOT part of a nucleotide?
Which component is NOT part of a nucleotide?
Signup and view all the answers
DNA replication occurs during the M-phase of the cell cycle.
DNA replication occurs during the M-phase of the cell cycle.
Signup and view all the answers
In eukaryotes, where is DNA found?
In eukaryotes, where is DNA found?
Signup and view all the answers
The backbone of the DNA molecule is made of alternating ______ and ______.
The backbone of the DNA molecule is made of alternating ______ and ______.
Signup and view all the answers
What is Chargaff's rule?
What is Chargaff's rule?
Signup and view all the answers
Study Notes
DNA Structure
- DNA controls all cellular activities
- Found in the nucleus of eukaryotic cells
- Found in the cytoplasm of prokaryotic cells (bacteria)
- DNA is an abbreviation for Deoxyribonucleic Acid
- DNA is a nucleic acid (one of four biomolecules)
- DNA is made of smaller building blocks called nucleotides
- Nucleotides have three parts:
- Deoxyribose sugar (a five-carbon, pentagon-shaped sugar)
- Phosphate group
- Nitrogenous base
- There are four types of nitrogenous bases:
- Thymine (T)
- Adenine (A)
- Cytosine (C)
- Guanine (G)
Nucleotide Structure
- A nucleotide's structure is characterized by a phosphate group bonded to a sugar (deoxyribose) molecule, which is, in turn, bonded to a nitrogenous base.
DNA Structure Details
- Nucleotides bond to form the DNA molecule
- DNA has a double helix shape, resembling a spiral staircase
- When unwound, DNA resembles a ladder, with alternating sugar and phosphate molecules forming the "rails" or "backbone"
- The "rungs" or "steps" of the DNA ladder are complementary base pairs held together by hydrogen bonds
- The complementary base pairs are: A with T, and C with G
Complementary Base Pairing
- Adenine (A) only bonds with Thymine (T)
- Cytosine (C) only bonds with Guanine (G)
- This specific pairing is known as Chargaff's rule
DNA Replication
- DNA must be copied for cell division, a process called replication
- Replication occurs during the S phase of interphase in the cell cycle
- Replication of DNA requires enzymes such as helicase to unzip the DNA and polymerase to assemble complimentary base pairs.
- The end result is two identical DNA molecules, each with one original and one new strand.
- This process is vital for cell growth and reproduction
DNA as the Universal Genetic Code
- All organisms' DNA share the same fundamental structure.
- Variations between species and individuals are due to differences in the sequence of nitrogenous bases (A, T, C, and G).
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz covers the essential components of DNA, including its structure, the role of nucleotides, and the specific nitrogenous bases involved. Understand how DNA controls cellular activities and learn about the double helix formation. Perfect for students studying biology or molecular genetics.
