Which part of the cell is responsible for making energy (ATP)?
The mitochondria
What type of bond holds two water molecules together?
A hydrogen bond.
What are the four main macromolecules of life?
Carbohydrates, lipids, proteins, and nucleic acids.
What does “semi-permeable membrane” mean?
It allows some molecules to pass but not others.
What’s the main difference between prokaryotic and eukaryotic cells?
Eukaryotic cells have a nucleus; prokaryotic cells don’t.
Why is water called a “polar molecule”?
Because it has a slightly positive and slightly negative side.
What are the building blocks of proteins?
Amino acids.
What type of transport does not need energy (ATP)?
Passive transport.
What organelle is responsible for packaging and transporting proteins?
The Golgi apparatus.
What does it mean that water has a high specific heat?
It resists changes in temperature.
Which molecule stores genetic information?
DNA
What happens to a cell in a hypertonic solution?
It shrinks as water leaves the cell.
What is the function of the cytoskeleton?
It helps maintain cell shape, supports movement, and organizes internal structures.
Why does ice float?
Ice is less dense because hydrogen bonds spread molecules apart.
What do lipids do in the cell membrane?
They form the phospholipid bilayer
Whats the difference between active and passive transport?
Active transport uses energy; passive transport doesn’t
What structure controls what enters and leaves the cell?
The plasma (cell) membrane.
How does water act as a solvent?
Its polarity allows it to dissolve charged or polar substances.
How do enzymes speed up reactions?
By lowering activation energy.
What does the sodium-potassium pump do?
It uses ATP to move sodium out and potassium into the cell.