Atomic Structure and Bonding
What type of bond involves sharing electrons between atoms?
Covalent bond
What property allows water molecules to stick to each other?
Cohesion
What is the monomer of proteins?
Amino acids
What type of reaction joins monomers into polymers?
Dehydration synthesis
In an experiment, what is the independent variable?
The variable that is deliberately changed or manipulated
What makes carbon so versatile in forming molecules essential to life?
It has four valence electrons and can form four covalent bonds.
What pH value is neutral?
7
What is the monomer of carbohydrates?
Monosaccharides (simple sugars like glucose)
What type of reaction breaks polymers into monomers?
Hydrolysis
In an experiment testing isopod behavior, what would the dependent variable be?
The environment chosen or movement of the isopods
What’s the difference between an ion and an isotope?
Ions differ by electrons/charge; isotopes differ by number of neutrons
Why is water called a polar molecule?
It has uneven charge distribution (O slightly negative, H slightly positive).
What macromolecule stores genetic information?
Nucleic acids (DNA/RNA)
In an enzyme-catalyzed reaction, what does the enzyme do?
Lowers activation energy and speeds up the reaction
A student collects temperatures: 23.5°C, 24.0°C, 24.5°C, 25.0°C. What’s the average?
24.25°C (≈24.3°C)
Deuterium is an isotope of hydrogen. What’s different about it?
It has one proton and one neutron instead of no neutrons.
Which two properties allow water to move up a plant’s xylem?
Cohesion and adhesion
What makes cellulose and starch different even though both are made of glucose?
They have different bond orientations between glucose monomers.
Why is water needed in hydrolysis reactions?
It provides H and OH groups that help break bonds between monomers.
Why is repetition important in experiments?
It increases reliability and reduces random error.
How do atoms achieve chemical stability?
By gaining, losing, or sharing electrons to fill their outer shell.
How does the bicarbonate buffer system maintain blood pH near 7.4?
It binds excess H⁺ ions to form carbonic acid, preventing pH drops.
Unsaturated fats differ from saturated fats because...
They contain double bonds, creating kinks in their fatty acid chains.
Explain how dehydration synthesis and hydrolysis help maintain energy balance in cells.
Dehydration builds storage molecules; hydrolysis releases usable energy.
A student records the height of bean plants over four weeks under different light conditions. What type of graph would best display the data?
A line graph — it shows change in plant height over time.