AP Biology Unit 2 - Cell Structure and Function

Eukaryotic cell

• Membrane-bound nucleus
• Membrane-bound organelles
• Linear chromosomes

Prokaryotic cell

• Nucleoid region
• Single, circular chromosome
• Membrane-bound organelles absent

Ribosome

• Made of rRNA
• Protein synthesis

Rough endoplasmic reticulum

• Has attached ribosomes
• Protein synthesis
• Modifies synthesized proteins
• Exports proteins

Smooth endoplasmic reticulum

• Synthesizes lipids, hormones, and cholesterol
• Detoxification
• Storage of calcium ions

Golgi apparatus

• Modifies, packages, and transports lipids and proteins
• Makes lysosomes and peroxisomes
• Made of cisternae

Lysosome

• Membrane-enclosed sac with hydrolytic enzymes
• Recycles organelles
• Has a lower pH than cytosol

Vesicle

• Small membrane-enclosed sac used for transport

Endomembrane system

• Group of membranes that interact with each other to modify, package, and transports lipids and proteins
• Includes the nuclear membrane, endoplasmic reticulum, Golgi apparatus, lysosomes, vesicles, and plasma membrane
• Does NOT include mitochondria, peroxisomes, or chloroplasts

Mitochondria

• Site of ATP synthesis
• Cristae, matrix, and double membrane
• Krebs cycle occurs in the matrix
• Electron transport chain occurs in the cristae

Chloroplast

• Found in plants and algae
• Site of photosynthesis
• Converts light energy into sugars
• Consists of thylakoids, grana, stroma, and a double membrane

Vacuole

• Membrane-bound organelle that stores and disposes substances
• In plants, stores water

Peroxisome

• Site of oxidation reactions
• Produces hydrogen peroxide

Psuedopod

• "False foot"
• An extension or contraction of the cell
• Can be used to move around or to attack

Cilia

• Hairlike projections extending from the cell
• Allows the cell to move around

Flagella

• Tail-like extension of the cell
• Enhances cell movement

Phospholipid

• Made of a hydrophilic head and two hydrophobic tails
• Amphipathic

Fluid mosaic model

The cell membrane consists of
• Glycolipids
• Glycoproteins
• Phospholipids
• Proteins
• Cholesterol

Cholesterol

• Controls the fluidity of the cell membrane
• Improves tolerance to temperature in cells

Integral protein

• A membrane protein that is integrated into the membrane

Peripheral protein

• A membrane protein resting on the membrane surface or on integral proteins
• May attach or remove themselves from the membrane

Channel protein

• A type of integral protein
• Supports cell homeostasis
• Allows ions to flow through the membrane via passive transport

Carrier protein

• A type of integral protein
• Can transport substances via active transport

Transmembrane protein

• A type of integral protein
• Spans the whole cell membrane

Glycoprotein

• A protein attached to carbohydrates
• Found externally on the cell membrane
• Used in cell signaling and cell recognition

Glycolipid

• A lipid attached to carbohydrates
• Found externally on the cell membrane

Semi-permeability

The ability of the cell membrane to let some substances pass
• Can pass rapidly: gases
• Can pass slowly: small, polar molecules; large, nonpolar molecules
• Cannot pass: charged ions