cell signaling
What are the four main types of cell signaling?
Paracrine, endocrine, autocrine, and contact-dependent.
What are the three cytoskeletal proteins?
Microtubules, microfilaments, and intermediate filaments.
Is DNA replication conservative or semi-conservative?
Semi-conservative,each daughter DNA has one old strand and one new strand.
What are the main stages of the cell cycle?
Gā, S, Gā, and M phase.
What is the difference between genotype and phenotype?
Genotype is the genetic makeup; phenotype is the observable trait.
What is required for signal transduction to occur?
A receptor to receive the signal and relay molecules to transmit it inside the cell.
What do integrins bind to?
the ECM
Which enzyme unwinds the DNA double helix?
helicase
What is cyclin?
A protein that regulates the activity of CDKs to control cell cycle progression.
What is an allele
Different forms of the same gene
What is the main difference between polar and nonpolar signaling molecules?
Polar signals bind to surface receptors, while nonpolar signals can cross the membrane and bind to intracellular receptors.
What do cadherins bind to?
Other Cadherins on adjacent cells
What does DNA polymerase do?
Synthesizes new DNA strands by adding nucleotides to the 3ā end.
What do CDKs do?
Activate or deactivate target proteins to trigger cell cycle transitions.
What is a point mutation
A change in a single nucleotide base pair in DNA
Which type of receptor often leads to short-term responses like activating enzymes or ion channels?
G protein-coupled receptors (GPCRs).
What is the difference between gap junctions and plasmodesmata?
Gap junctions connect animal cells; plasmodesmata connect plant cells.
What is the role of ligase in DNA replication?
Joins Okazaki fragments on the lagging strand.
How do cancer cells differ from normal cells?
They divide uncontrollably and ignore normal growth regulation signals.
What is a frame shift mutation, and how does it affect a gene.
Caused by insertion or deletion; shifts the reading frame and alters the entire amino acid sequence.
Which type of receptor leads to long-term responses by changing gene expression?
Receptor kinases.
What is the function of desmosomes?
They anchor intermediate filaments and provide strong cell-cell adhesion.
What makes DNA replication in eukaryotes more complex than in prokaryotes?
Multiple origins of replication and linear chromosomes that require telomeres.
How is the cell cycle regulated to ensure proper division?
By checkpoints that monitor DNA damage, replication, and spindle attachment.
What are mutagens, and what is their role in DNA change?
Physical or chemical agents that cause mutations; most DNA damage is later repaired by the cell.