College Board-Aligned Original Notes
AP Biology Unit 2 Topic 1: Cellular structure and functions
Cell structures are organized so that each part contributes to transport, energy conversion, information storage, growth, or communication.
Unit 2: Cells. College Board exam weighting listed for this unit: 10%-13% of exam score.
What to Know
- Prokaryotic cells lack membrane-bound organelles, while eukaryotic cells use internal compartments.
- Ribosomes, membranes, cytoskeleton elements, and organelles work together rather than acting as isolated parts.
- Structure-function reasoning explains why specialized cells contain different amounts of specific organelles.
- Always connect this topic back to the larger unit: Cells.
Detailed Notes
Cellular structure and functions belongs to Unit 2: Cells. Cell structures are organized so that each part contributes to transport, energy conversion, information storage, growth, or communication. Treat the topic as a relationship between structure, process, evidence, and biological function instead of memorizing an isolated definition.
Key relationships: Prokaryotic cells lack membrane-bound organelles, while eukaryotic cells use internal compartments. Ribosomes, membranes, cytoskeleton elements, and organelles work together rather than acting as isolated parts. Structure-function reasoning explains why specialized cells contain different amounts of specific organelles.
Model to use: Compare a prokaryotic cell and a eukaryotic cell by labeling which structures are shared and which are compartmentalized. A clear model should label the parts, show the direction of movement or information flow when relevant, and connect the diagram back to the biological outcome.
AP-style move: When given a cell image or scenario, identify the structure first, then explain how its structure supports its job. Strong answers name the concept, apply it to the scenario, and explain the reasoning in complete sentences.
Key Vocabulary
Ribosome
A cellular structure that builds proteins by linking amino acids.
Cytosol
The fluid portion of the cytoplasm where many reactions occur.
Cytoskeleton
A network of protein fibers that supports shape, movement, and internal organization.
Eukaryote
An organism whose cells contain a nucleus and membrane-bound organelles.
Prokaryote
An organism whose cells lack a nucleus and membrane-bound organelles.
Organelle
A specialized cell structure that performs a particular function.
Quick Practice
How would you explain Cellular structure and functions in one or two AP-style sentences?
Name the concept, apply it to a specific example or source, and explain the reasoning that connects the evidence to your answer.
Related Topics in This Unit
- Cell size
- Cellular interactions with its environment
- Plasma membrane and membrane transport
- Cell regulatory mechanisms (like osmosis and selective permeability)
Official Alignment
Reference and Attribution
Biology concept reference: Biology for AP Courses by OpenStax, Rice University. Access for free at OpenStax. Licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License. EduCompanion used this source as a conceptual reference and rewrote the study notes in original wording.