Cell Theory & Evolution of Life
This scientist observed living cells ("animalcules") using a microscope he designed, building upon Robert Hooke’s initial discovery of cork cells.
Antonie van Leeuwenhoek
DNA is made up of nucleotides consisting of these three components.
5-carbon sugar (deoxyribose), a phosphate group, and a nitrogenous base
What is the Central Dogma of Molecular Biology?
The flow of genetic information from DNA to RNA to Protein is known by this fundamental concept.
What is a Peptide Bond?
This type of covalent bond connects the carboxyl group of one amino acid to the amino group of another during protein synthesis.
These 3-base sequences on mRNA are read by the ribosome, while tRNAs bring corresponding amino acids using complementary 3-base sequences called these.
Codons and Anticodons
What are the three components of the Cell Theory?
All organisms are composed of one or more cells, the cell is the basic unit of structure and organization, and all cells come from pre-existing cells.
If a sample of double-stranded DNA contains 10% Cytosine (C), what percentage of the sample is Thymine (T)
40%
What is the TATA box?
In eukaryotic transcription, this sequence located in the promoter region serves as the binding site for general transcription factors and RNA polymerase.
Secondary structures such as the Alpha helix and Beta sheet are stabilized primarily by this type of non-covalent bond between backbone atoms.
Hydrogen bonds
What is the A (aminoacyl) site?
During translation elongation, tRNAs carrying new amino acids enter the ribosome at this site before moving to the P site.
While eukaryotic DNA is linear and bound by histones inside a nucleus, prokaryotic DNA typically has this shape and placement within the cell.
Circular DNA located in the nucleoid region
This 1928 experiment demonstrated transformation in Streptococcus pneumoniae, showing that a heat-killed virulent strain could transfer genetic information to a harmless strain.
Griffith’s Experiment
Name the three post-transcriptional modifications that a eukaryotic primary RNA transcript (pre-mRNA) must undergo before export to the cytoplasm.
Addition of a 5' cap, Polyadenylation (addition of a 3' Poly-A tail), RNA Splicing (removal of introns, joining of exons
Tertiary structure represents the overall 3D shape of a single polypeptide chain and is driven primarily by interactions between these molecular components.
R groups
What is a Nonsense Mutation?
This type of point mutation changes a codon specifying an amino acid into a premature stop codon, leading to a shorter protein.
Name three key structural differences between Eukaryotic and Prokaryotic cells.
Eukaryotes have a membrane-bound nucleus (Prokaryotes store DNA in a nucleoid region with no membrane), Eukaryotes have membrane-bound organelles, Eukaryotes are typically larger/more complex, whereas Prokaryotes are smaller and mostly single-celled
In 1944, Avery, MacLeod, and McCarty proved DNA was the genetic material by using enzymes to destroy proteins, RNA, and DNA sequentially. Only destroying this molecule prevented transformation.
DNA
These non-coding regions are removed during RNA splicing, while these coding regions are joined together.
Introns (removed) and Exons (stay)
Amino acids with nonpolar R groups (such as Leucine or Valine) are classified as this, meaning they tend to cluster in the interior of a folded protein away from water.
Hydrophobic
What is charging tRNA (attaching the correct amino acid to its corresponding tRNA)?
An enzyme called Aminoacyl tRNA synthetase performs this important step prior to translation.
Archaea are more closely related to this domain of life than they are to Bacteria.
Eukarya
These two nitrogenous bases belong to the Purine family and possess a double-ring structure.
Adenine and Guanine
What is alternative splicing?
This process allows a single gene to encode multiple distinct protein isoforms by selecting different combinations of exons.
Infectious, misfolded proteins that cause normal proteins to misfold into disease-causing shapes are called this.
Prions
If a mutation replaces a nonpolar amino acid (like Leucine) with another nonpolar amino acid (like Isoleucine), it is classified as this type of missense mutation.
Conservative Mutation