AP BIO UNIT 2 STUDY GUIDE

What organelles are found in animal cells but not in plant cells?

Centrioles and lysosomes.

What organelles are found in plant cells but not in animal cells?

Chloroplasts and cell walls.

How do ribosomes assist in protein synthesis?

Ribosomes translate mRNA into polypeptide chains, following the instructions encoded in DNA.

If a cell has a high rate of protein synthesis, which organelle would be abundant?

The rough endoplasmic reticulum (ER) due to its role in protein production.

What are the main differences between rough and smooth ER?

Rough ER has ribosomes on its surface and synthesizes proteins, while smooth ER lacks ribosomes and is involved in lipid synthesis and detoxification.

What are the main differences between prokaryotic and eukaryotic cells?

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells have a nucleus and organelles.

What is the endomembrane system?

A network of membranes that includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and plasma membrane, involved in protein and lipid synthesis and transport.

Trace the path of a protein from production to final product.

Ribosomes on the rough ER synthesize the protein, which is then modified in the ER, packaged in vesicles, sent to the Golgi apparatus for further modification, and finally transported to the plasma membrane or secreted.

Do plant cells have a plasma membrane despite having a cell wall?

True. Plant cells have both a cell wall and a plasma membrane.

Do plant cells lack mitochondria because they perform photosynthesis?

Disagree. Plant cells have mitochondria for cellular respiration in addition to chloroplasts for photosynthesis.

How is the Golgi Complex similar to a warehouse/mail facility?

The Golgi Complex modifies, sorts, and packages proteins for transport, similar to how a warehouse prepares and sends out packages.

What is the ideal surface area-to-volume ratio for cells to optimize material exchange?

A high surface area-to-volume ratio is ideal for efficient exchange of materials.

What problems arise if a single cell continues to grow larger?

Issues include decreased efficiency in nutrient uptake and waste removal due to a lower surface area-to-volume ratio.

Which cell has the most efficient exchange across its membrane based on surface area-to-volume ratios: 2.0, 0.9, or 1.2?

The cell with a ratio of 2.0.

Which cell would be best suited for storage based on surface area-to-volume ratios: 4.5, 7.2, 3.1, or 5.5?

The cell with a ratio of 3.1.

What is the fluid mosaic model of the plasma membrane?

It describes the plasma membrane as a dynamic structure with various proteins embedded in a fluid phospholipid bilayer.

What causes kinks in the tails of phospholipids?

Kinks are caused by the presence of unsaturated fatty acids in the phospholipid tails.

What molecule affects membrane fluidity?

Cholesterol embeds itself within the membrane and maintains fluidity by preventing fatty acid chains from packing too closely.

Differentiate between integral and peripheral proteins.

Integral proteins span the membrane and are involved in transport, while peripheral proteins are attached to the membrane surface and play roles in signaling and structural support.

What does it mean that the plasma membrane is selectively permeable?

It allows certain substances to pass while restricting others, maintaining homeostasis.

Are nonpolar molecules hydrophobic or hydrophilic?

Nonpolar molecules are hydrophobic, meaning they do not easily pass through the plasma membrane.

Are polar molecules hydrophobic or hydrophilic?

Polar molecules are hydrophilic, which affects their ability to cross the plasma membrane without assistance.

What are the main differences between passive and active transport?

Passive transport does not require energy and moves substances down their concentration gradient, while active transport requires energy to move substances against their gradient.

What type of transport is exemplified by the smell of popcorn spreading in a room?

Diffusion.

What is necessary for active transport?

ATP (adenosine triphosphate) is required for active transport.

Is facilitated diffusion a type of active or passive transport?

Facilitated diffusion is a type of passive transport because it does not require energy.

What are the two types of transport proteins?

Channel proteins and carrier proteins.

What are the effects of a mutation in aquaporin proteins?

A mutation could impair water transport, affecting cell hydration and function.

What is the endosymbiotic theory?

It proposes that mitochondria and chloroplasts originated from free-living prokaryotes that were engulfed by ancestral eukaryotic cells.