Scientists & Cell Theory
Who named “cells” after looking at cork?
Robert Hooke
What is the function of the mitochondria?
Produces ATP (energy).
What model describes the cell membrane structure?
Fluid Mosaic Model
Does diffusion require energy? Why?
No (passive).
What type of cell has no nucleus?
Prokaryotic cell
Which two scientists said all plants and all animals are made of cells?
Schleiden (plants) & Schwann (animals)
What two structures are found in plant cells but not in animal cells?
Chloroplasts & cell wall.
Describe a phospholipid and identify hydrophilic and hydrophobic parts.
Head = hydrophilic, tails = hydrophobic.
What is osmosis?
Diffusion of water across a membrane.
Name the three basic types of cells.
Bacterial, plant, animal
State the three principles of the Cell Theory.
1. All living things are made of cells. 2. Cells are the basic unit of life. 3. All cells come from pre-existing cells.
Explain the function of the Golgi apparatus.
Modifies, packages, and ships proteins.
What is the role of cholesterol in the cell membrane?
Prevents fatty acid tails from sticking and adds flexibility
How is facilitated diffusion different from simple diffusion?
Facilitated uses transport proteins.
What structure helps maintain homeostasis?
Cell membrane
Explain how Virchow’s discovery supported the Cell Theory.
He stated that new cells come from pre-existing cells, supporting principle #3.
Compare the functions of ribosomes and the endoplasmic reticulum.
Ribosomes make proteins; ER transports/makes proteins & lipids.
Explain how the structure of the phospholipid bilayer allows selective permeability
Hydrophobic core blocks polar molecules; proteins allow specific substances to pass.
Compare active transport and passive transport using concentration gradients and energy.
Passive = high → low, no energy; Active = low → high, needs ATP.
Compare prokaryotic and eukaryotic cells (at least 2 differences).
Prokaryotes have no nucleus, are smaller; eukaryotes have nucleus & organelles.
Compare the discoveries of Leeuwenhoek and Hooke and explain how both contributed to the Cell Theory.
Hooke named “cells” (dead cells), Leeuwenhoek observed living cells—both helped define and expand knowledge of cells.
Describe how the nucleus, ribosomes, and mitochondria work together to maintain homeostasis
Nucleus gives DNA instructions → ribosomes make proteins → mitochondria use proteins to make ATP.
How do carbohydrates and receptor proteins help cells communicate?
Carbohydrates identify cells; receptor proteins receive chemical signals.
Explain how the sodium-potassium pump works.
Uses ATP to move 3 Na⁺ out and 2 K⁺ in against concentration gradient.
Explain how the cell membrane helps maintain homeostasis using transport mechanisms.
Controls what enters/exits using passive and active transport to maintain balance.