Big Cell, Small Cell
Which cell type keeps its DNA in a nucleoid region, with no membrane?
Prokaryotic cells.
What dots the surface of the rough ER and gives it its bumpy look?
Ribosomes
Which organelle carries out cellular respiration to make ATP?
The mitochondrion
What molecule makes up most of a cell membrane, with water-loving heads and water-fearing tails?
Phospholipids
Which type of transport needs ATP: passive or active?
Active transport.
A swab holds Cell X (about 1 μm long) and Cell Y (about 30 μm across). Which one is most likely eukaryotic?
Cell Y.
Hemoglobin is built from four polypeptide chains that work as one unit. What level of protein structure is that?
Quaternary structure
TRUE or FALSE: Cytoplasm is found only in eukaryotic cells.
FALSE.
This molecule is important in membrane fluidity, decreasing and increasing fluidity depending on the temperature.
Cholesterol
How does CO₂ leave a cell? Does it need a transport protein?
Simple diffusion. No protein needed.
What type of cell has a singular circular chromosome in the cytosol?
Prokaryote
A protein picks up a sugar chain as it passes through the Golgi. What is this process called?
Glycosylation
A heart muscle cell has thousands of mitochondria. A skin cell has far fewer. Why?
Heart muscle uses much more energy, so it needs more mitochondria to make ATP.
Your immune system recognizes “self” cells, and labs can tell blood types apart. What molecules on the outer cell surface make this possible?
Carbohydrate chains on glycoproteins and glycolipids
A red blood cell is dropped into distilled water (hypotonic). Which way does water move, and mainly through what?
Into the cell by osmosis, mainly through aquaporins. The cell swells and may burst.
Name THREE structures found in every cell.
Extra 200 pts: Explain why each one is needed.
plasma membrane (controls what enters and leaves), cytoplasm (keeps organelles in a floating state), ribosomes (make proteins), DNA (holds instructions).
Free ribosomes vs. bound ribosomes. Which kind makes a protein that will be secreted, and which makes a protein that stays in the cytosol?
Bound ribosomes (on the rough ER) make secreted proteins. Free ribosomes make cytosol proteins.
Plant cells often have more Golgi membranes than animal cells. What plant-only structure is the Golgi helping to build?
The cell wall.
In the fluid mosaic model, what does “fluid” mean? What does “mosaic” mean?
Fluid: lipids and proteins drift and create flexibility in the membrane. Mosaic: a patchwork of proteins, cholesterol, and carbohydrates set in the bilayer.
The Na⁺/K⁺ pump moves 3 Na⁺ out and 2 K⁺ in. Is it a uniporter, symporter, or antiporter?
Antiporter. It moves substances in opposite directions using ATP.
What is the theory that mitochondria and chloroplasts were once free-living prokaryotes. Evidence that supports this theory includes that these organelles have their own circular DNA, bacteria-like ribosomes, double membrane, divide by splitting like bacteria.
Endosymbiotic theory
A drug shuts down the Golgi apparatus. Predict what happens to a hormone the cell normally secretes.
It is not modified, sorted, or packaged. It piles up and is not secreted.
This cytoskeleton structure makes up spindle fibers that assist in chromosome separation, cilia and flagella, and vesicle tracks.
Microtubules
One bacterial culture grows at 10 °C and another at 40 °C. Which will likely have more unsaturated, kinked fatty-acid tails in its membranes? Why?
The 10 °C culture. Kinks stop the tails from packing tightly, so the membrane stays fluid in the cold.
Name the three kinds of endocytosis.
Phagocytosis, pinocytosis, receptor-mediated endocytosis.