AP Biology Unit 2 - Chapter 6, 7, and 36 Harder Concepts Quizlet

What are the two main types of microscopes and their differences?

Light microscope: lower resolution, can see living cells

Electron microscope has higher resolution, can't see living cells, and the different types are TEM = internal and SEM = 3D surface.

Why are cells small?

Small cells have a larger surface area-to-volume ratio, which allows faster and more efficient exchange of materials.

What limits the maximum size of a cell?

Too little surface area relative to volume → inefficient transport of nutrients and waste.

Where is the highest concentration of radioactivity found in a cell after adding radioactive amino acids?

First in the rough ER (protein synthesis), then Golgi, then secretory vesicles/outside cell.

Which organelles are part of the endomembrane system?

Nuclear envelope, rough/smooth ER, Golgi apparatus, lysosomes, vesicles, plasma membrane, vacuoles.

Which organelles are NOT part of the endomembrane system?

Mitochondria and chloroplasts (they evolved from endosymbiosis).

Which proteins are synthesized in the rough ER?

Proteins that will be secreted, inserted into membranes, or sent to lysosomes.

What is synthesized in the smooth ER?

Lipids (not proteins).

Which organelle takes up the most space in a plant cell?

The central vacuole.

What do prokaryotic and eukaryotic cells both have?

Cell membrane, cytoplasm, DNA, ribosomes.

What do only eukaryotic cells have?

Nucleus and membrane-bound organelles (ER, Golgi, mitochondria, etc.).

What do only prokaryotic cells lack?

A nucleus and membrane-bound organelles.

What is needed to form cilia and flagella?

Microtubules in a 9+2 arrangement, basal bodies, and dynein motor proteins.

How do cilia and flagella move?

Dynein uses ATP to slide microtubules; anchoring causes bending. Cilia beat back-and-forth, flagella move in a whip-like motion.

Some regions of the plasma membrane, called lipid rafts, have a higher concentration of cholesterol molecules. At higher temperatures, these regions...

are less fluid than the surrounding membrane.

In order for a protein to be an integral membrane protein it would have to be...

amphipathic, with at least one hydrophobic region.

Why are lipids and proteins free to move laterally in membranes?

There are only weak hydrophobic interactions in the interior of the membrane.

Where is Cholesterol located in the cell membrane?

Cholesterol is located within the phospholipid bilayer of the cell membrane, tucked between the hydrophobic tails of the phospholipids.

Water passes quickly through the cell membrane because...

it moves through aquaporins in the membrane.

The movement of small, hydrophobic gas, Nitrous Oxide (N2O) (Laughing Gas) into a cell is an example of...

Diffusion across the lipid bilayer.

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M solution become limp and soft. From this we can deduce that...

The fresh water is hypotonic and the salt solution is hypertonic to the cells of the celery stalk.

Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains approximately 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?

Water will leave the cells, causing them to shrivel and collapse.

What is the normal tonicity conditions for plant and animal cells?

The animal cell is in an isotonic solution and the plant cell is in a hypotonic solution.

The difference between pinocytosis and receptor-mediated endocytosis is that...

Pinocytosis is non-selective of in the molecules it brings into the cell, whereas receptor-mediated offers more selectivity.

Which of the following statements about xylem is incorrect?

A. The conducting cells are part of the apoplast.

B. It typically has a lower water potential than is found in soil.

C. It transports sugar and mainly amino acids.

D. No energy input is required for transport.

C. It transports sugar and mainly amino acids.

Phloem transport is described as being from source to sink. Which of the following would most accurately complete this statement about phloem transport as applied to most plants in the late spring?

Statement: Phloem transports ______ from the ______ source to the ______ sink.

A. amino acids; root; mycorrhizae

B. sugars; stem; root

C. proteins; root; leaf

D. sugars; leaf; apical meristem

D. sugars; leaf; apical meristem

Which structure or compartment is part of the symplast?

The interior of a sieve tube.

How do you calculate solute potential?

To calculate solute potential in AP Biology, use the formula Ψs = -iCRT.

i: is the ionization constant (e.g., 1 for sucrose and glucose, 2 for NaCl).

C: is the molar concentration of the solute.

R: is the pressure constant, typically 0.0831 L·bars/mol·K.

T: is the temperature in Kelvin, found by adding 273 to the temperature in degrees Celsius