Podcast Beta
Questions and Answers
What does DNA stand for?
Deoxyribonucleic Acid
DNA is only found in the nucleus of eukaryotic cells.
False
Who discovered the structure of DNA?
James Watson and Francis Crick
What is the structure of DNA commonly described as?
Signup and view all the answers
Which of the following are components of DNA?
Signup and view all the answers
What is the melting temperature (Tm) of DNA?
Signup and view all the answers
What are the four types of nitrogen bases found in DNA?
Signup and view all the answers
What bonds hold the nitrogen bases together in DNA?
Signup and view all the answers
The diameter of the double helix structure of DNA is 2nm.
Signup and view all the answers
What are the two types of DNA based on location?
Signup and view all the answers
What type of DNA is usually diploid?
Signup and view all the answers
Study Notes
DNA - Structure, Properties, Types, and Functions
- DNA is a molecule that contains the genetic instructions for an organism's development, life, and reproduction.
- DNA is found in every cell and is passed down from parents to their children.
- DNA is a nucleic acid and is one of the four major types of macromolecules essential for life.
DNA Structure
- DNA's structure is a double helix, like a twisted ladder.
- The sides of the ladder are made of alternating sugar (deoxyribose) and phosphate molecules.
- The steps of the ladder are made up of nitrogenous bases adenine (A), thymine (T), guanine (G), and cytosine (C).
- Bases pair specifically: A with T, and G with, held together by hydrogen bonds.
Detailed Structure and Composition
- DNA is a double-stranded helix composed of two biopolymer strands.
- Each strand is called a polynucleotide, made of simpler monomer units called nucleotides.
- Each strand has a 5' end (with a phosphate group) and a 3' end (with a hydroxyl group).
- The strands are antiparallel, running in opposite directions (5' to 3' and 3' to 5').
- The two strands are held together by hydrogen bonds and are complementary to each other.
Major and Minor Grooves
- The double helix creates two grooves: a major groove (where the backbones are far apart) and a minor groove (where they are close together).
- These grooves expose the edges of the bases, allowing proteins to recognize specific DNA sequences.
Properties of DNA
- DNA helices can be right-handed or left-handed, but the B conformation (right-handed) is the most stable.
- Heating separates the two strands of DNA, and cooling allows them to re-hybridize.
- The temperature at which the strands separate completely is called the melting temperature (Tm), which is specific to each sequence.
- Sequences with higher GC content have a higher melting temperature because G-C pairs have three hydrogen bonds.
Types of DNA
- Eukaryotic organisms store most of their DNA in the cell nucleus and some in organelles like mitochondria.
Nuclear DNA
- Located within the nucleus of eukaryote cells.
- Typically has two copies per cell.
- Nuclear DNA chromosomes are linear with open ends, containing 46 chromosomes with 3 billion nucleotides.
- Nuclear DNA is diploid, with DNA inherited from both parents.
- Nuclear DNA mutation rate is less than 0.3%.
Mitochondrial DNA
- Located in mitochondria.
- Contains a circular chromosome.
- Has multiple copies per cell.
- Inherited maternally, meaning it's passed down from the mother.
- Mutation rate is higher than nuclear DNA, at about 1%.
Functions of DNA
- DNA carries genetic information.
- DNA replicates to pass genetic information to daughter cells.
- DNA is transcribed into RNA, which is then translated into proteins.
- DNA mutations can lead to changes in protein function, which can have various effects on the organism.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the structure, properties, and functions of DNA with this quiz. Explore concepts such as the double helix formation, nucleotide composition, and the roles of DNA in genetics. Perfect for students studying molecular biology or genetics!
