Microbial Genetics: DNA, RNA, Chromosomes, and Components Flashcards
What is the basic building block of nucleic acids?
Nucleotides
Nucleotides are composed of a five-carbon sugar, a phosphate group, and a nitrogen-containing base.
What sugar is found in DNA?
Deoxyribose
Deoxyribose is a five-carbon sugar specific to DNA.
Which nitrogen base pairs with adenine in DNA?
Thymine
Adenine forms hydrogen bonds with thymine in the double helix structure of DNA.
What is the structure of DNA?
Double stranded helix
DNA’s double helix is formed by the pairing of nitrogenous bases and the sugar-phosphate backbone.
What sugar is found in RNA?
Ribose
Ribose is a five-carbon sugar found in RNA.
Which nitrogen base pairs with adenine in RNA?
Uracil
Uracil replaces thymine in RNA and pairs with adenine.
What is a chromosome?
A strand of nucleic acids and associated proteins that carry genetic information
Chromosomes are typically located in the nucleus of eukaryotic cells and in the nucleoid of bacteria.
What is a genome?
An organism’s complete set of DNA (or RNA in some viruses)
The genome contains all the genetic information necessary for the organism’s maintenance.
What type of DNA do bacteria usually have?
Circular DNA
Bacteria can also contain plasmids, which are extra-chromosomal circular DNA molecules.
How many histone proteins make up a nucleosome?
8
The nucleosome consists of 4 different histone proteins, with 2 of each type.
What role do histone proteins play in DNA?
They help package DNA into chromosomes
Histones also regulate genes and protect DNA from damage.
What enzyme binds to DNA during transcription?
RNA polymerase
RNA polymerase is essential for synthesizing RNA from a DNA template.
What is the term for the process of DNA replication involving enzymes?
Helicase and topoisomerase
These enzymes help unwind and manage the DNA structure during replication.
True or False: Guanine binds with cytosine in DNA.
True
Guanine and cytosine pair through hydrogen bonding in the DNA structure.
Fill in the blank: The chromosome of an organism is the strand of _______ and associated proteins that carries genetic information.
nucleic acids
Chromosomes are vital for storing and transmitting genetic information.
What is an endosome?
A membrane-bound compartment
Endosomes sort and transport materials within eukaryotic cells.
What is a centrosome?
An organelle that contains centrioles
Centrosomes play a crucial role in cell division in animal cells.
What does RNA stand for?
Ribonucleic Acid
What does DNA stand for?
Deoxyribonucleic Acid
True or False: RNA is typically single-stranded.
True
True or False: DNA is typically double-stranded.
True
What sugar is found in RNA?
Ribose
What sugar is found in DNA?
Deoxyribose
Fill in the blank: The base ______ is found in RNA but not in DNA.
Uracil
Which base is replaced by uracil in RNA?
Thymine
What is the primary function of RNA?
To transfer genetic information from DNA to proteins
What is the primary function of DNA?
To store and transmit genetic information
Multiple Choice: Which type of RNA carries amino acids to the ribosome?
Transfer RNA (tRNA)
Multiple Choice: Which type of RNA is involved in protein synthesis?
Messenger RNA (mRNA)
What is the process called by which DNA is copied into RNA?
Transcription
What is the process called by which RNA is used to synthesize proteins?
Translation
True or False: DNA can be found in the cytoplasm of eukaryotic cells.
False
Where is DNA primarily located in a eukaryotic cell?
Nucleus
What is the shape of DNA?
Double helix
What is the shape of RNA?
Single-stranded
True or False: Both RNA and DNA contain the same four bases.
False
What type of bond links nucleotides in a DNA strand?
Phosphodiester bond
What type of bond links nucleotides in an RNA strand?
Phosphodiester bond
Fill in the blank: DNA replication is __________ while RNA synthesis is __________.
semi-conservative, non-conservative
What enzyme is responsible for synthesizing RNA from a DNA template?
RNA polymerase
What is the role of ribosomal RNA (rRNA)?
To form the core of the ribosome’s structure and catalyze protein synthesis
What is the main type of RNA involved in carrying instructions from DNA to the ribosome?
Messenger RNA (mRNA)
Multiple Choice: Which type of RNA is responsible for bringing amino acids to the ribosome?
Transfer RNA (tRNA)
True or False: RNA can act as a catalyst.
True
What are the three main types of RNA?
mRNA, tRNA, rRNA
What is the term for the sequence of nucleotides in DNA that codes for a protein?
Gene
What is the complementary base pairing for adenine in DNA?
Thymine
What is the complementary base pairing for adenine in RNA?
Uracil
Fill in the blank: The process of converting mRNA into a polypeptide chain is called __________.
Translation
What is a key difference between prokaryotic and eukaryotic RNA processing?
Eukaryotic RNA undergoes splicing, capping, and polyadenylation
True or False: DNA is more stable than RNA.
True
What is the role of the promoter in transcription?
To initiate the transcription of a gene
What is the role of the terminator in transcription?
To signal the end of transcription
Multiple Choice: Which type of RNA is not involved in protein synthesis?
Ribosomal RNA (rRNA)
What is the significance of the 5’ cap on mRNA?
It protects mRNA from degradation and assists in ribosome binding
What is the significance of the poly-A tail on mRNA?
It enhances the stability of the mRNA molecule
Fill in the blank: The genetic code is read in _______ during translation.
Codons
What is the function of aminoacyl-tRNA synthetase?
To attach the correct amino acid to its corresponding tRNA
True or False: Mutations in DNA can lead to changes in RNA and ultimately proteins.
True
What is a codon?
A sequence of three nucleotides in mRNA that codes for an amino acid
What is the difference in stability between RNA and DNA?
RNA is less stable due to the presence of the 2’ hydroxyl group in ribose.
