AP Biology Final Exam Review

Front

What is chemical equilibrium in the context of living cells?

Back

Chemical equilibrium refers to a state in a chemical reaction where the concentrations of reactants and products remain constant over time, indicating that the forward and reverse reactions occur at the same rate. In living cells, true chemical equilibrium is rare due to constant metabolic activity.

Front

Where are hydrophobic amino acids typically found in a protein structure?

Back

Hydrophobic amino acids, like valine, are typically found in the interior of the folded protein, away from water, or in the transmembrane portion interacting with lipid fatty acid chains.

Front

What structural changes occur in sickle-cell hemoglobin compared to normal hemoglobin?

Back

Sickle-cell hemoglobin exhibits altered primary structure due to a single amino acid change and altered quaternary structure as the mutant hemoglobin tetramers associate and form large fibers.

Front

What is the role of protein kinases in cellular signaling?

Back

Protein kinases transfer the terminal phosphate from ATP to specific amino acid residues on target proteins, often located on the plasma membrane, allowing them to readily encounter and phosphorylate other membrane proteins.

Front

What does the second law of thermodynamics state about chemical reactions?

Back

The second law of thermodynamics states that every chemical reaction must increase the total entropy of the universe, meaning that energy transformations are not 100% efficient and some energy is always lost as heat.

Front

Define entropy in the context of thermodynamics.

Back

Entropy is a measure of the disorder or randomness in a system. In thermodynamics, it quantifies the amount of energy in a physical system that is not available to do work.

Front

What is the significance of the primary structure of a protein?

Back

The primary structure of a protein refers to the unique sequence of amino acids that determines the protein's shape and function. Changes in this sequence can lead to altered protein function.

Front

Explain the concept of quaternary structure in proteins.

Back

Quaternary structure refers to the arrangement and interaction of multiple polypeptide chains (subunits) in a protein. It is crucial for the protein's overall function and stability.

Front

What is the function of ATP in cellular processes?

Back

ATP (adenosine triphosphate) serves as the primary energy currency of the cell, providing energy for various biochemical reactions, including muscle contraction, nerve impulse propagation, and biosynthesis.

Front

How do enzymes lower activation energy in biochemical reactions?

Back

Enzymes lower activation energy by providing an alternative reaction pathway, stabilizing the transition state, and facilitating the formation of products more efficiently.