Big Ideas in Biology
What concept explains why all organisms share DNA but look very different?
What is evolution?
Which subatomic particle determines an atom’s identity?
What is the proton?
What monomers make up proteins?
What are amino acids?
What cell structure regulates what enters and leaves the cell?
What is the plasma membrane?
Which molecule is known as the “energy currency” of the cell?
What is ATP?
The smallest unit of life that can function independently is the ______.
What is a cell?
Which type of bond involves the transfer of electrons?
What is an ionic bond?
Which protein structure level describes α-helices and β-sheets?
What is secondary structure?
Which organelle packages and modifies proteins for export?
What is the Golgi apparatus?
What type of reaction builds larger molecules from smaller ones?
What is an anabolic reaction?
What is an emergent property? Give an example.
A property that arises from interactions of smaller parts. Example: consciousness emerges from neural interactions.
Why is water cohesive?
Because of hydrogen bonding between water molecules.
What happens when a protein is denatured?
It loses its shape (and function) due to disruption of bonds.
What’s the difference between prokaryotic and eukaryotic DNA storage?
Prokaryotic DNA is circular and free in cytoplasm; eukaryotic DNA is linear and stored in the nucleus.
Define activation energy.
The energy needed to start a reaction by bringing reactants to the transition state.
Which domain of life includes organisms with nuclei?
What is Eukarya?
What is a buffer, and why is it important in cells?
A buffer stabilizes pH by absorbing/releasing H⁺; important to keep enzymes functioning.
What is allosteric regulation of an enzyme?
A regulatory molecule binds at a site other than the active site, changing enzyme activity.
What is endosymbiosis, and which organelles support this theory?
Theory that mitochondria and chloroplasts originated from engulfed prokaryotes; both have DNA and double membranes.
Why is cellular respiration more efficient than fermentation?
Because respiration fully oxidizes glucose, producing ~30–32 ATP, while fermentation yields only 2 ATP.
Name two characteristics that define living things.
reproduction, energy use/metabolism, homeostasis, response to environment, growth, evolutionary adaptation.
Compare hydrophobic and hydrophilic interactions.
Hydrophobic = nonpolar molecules avoid water; Hydrophilic = polar molecules dissolve/interact with water.
Why do enzymes only catalyze specific reactions?
Because their active sites are shaped to fit only certain substrates.
How does cholesterol affect membrane fluidity?
It stabilizes membranes: reducing fluidity at high temps, preventing rigidity at low temps.
What role do NADH and FADH₂ play in metabolism?
They carry high-energy electrons to the electron transport chain for ATP production.