DNA Structure and Function Quiz

DNA Structure and Components

• Adenine pairs with thymine (A-T) as complementary nucleotides in DNA.
• Two DNA strands form a double helix structure, coiled around each other.
• Basic units of DNA are nucleotides, consisting of a phosphate group, a deoxyribose sugar, and a nitrogenous base.
• Guanine pairs with cytosine (G-C) as the complementary nucleotide base.

RNA Structure and Function

• In RNA, the base sequence representation for adenine, uracil, cytosine, and guanine is A-U-C-G.
• RNA contains uracil (U), which is not present in DNA.
• RNA typically exists as a single-stranded molecule.

Genetic Information and Chromosomes

• DNA molecules store genetic information for cellular functions.
• Chromosomes are located in the nucleus of eukaryotic cells.
• Primary composition of chromosomes includes DNA tightly coiled around histone proteins.
• Humans generally have 46 chromosomes, organized in 23 pairs.

Codons and Protein Synthesis

• A codon consists of three nucleotides and serves as a unit of genetic code during protein synthesis.
• Codons correspond to specific amino acids in the protein assembly process.

Nucleotide Structure

• A nucleotide in DNA comprises a phosphate group, a deoxyribose sugar, and a nitrogenous base.
• The double helix structure of DNA is maintained by hydrogen bonds between complementary base pairs.
• The backbone of each DNA strand is formed by alternating phosphate groups and deoxyribose sugars.

DNA Directionality and Transcription

• The 5' end of DNA has a phosphate group attached to the 5' carbon of the deoxyribose sugar.
• The 3' end features a hydroxyl group (-OH) attached to the 3' carbon of the deoxyribose sugar, important for the directionality during replication and transcription.
• RNA polymerase, the enzyme responsible for transcription, binds to a promoter region on the DNA to initiate the process.
• The terminator signals the end of transcription, ensuring the RNA molecule is properly completed.