7.5 ProteinsLearning Target: Explain the significance of polar and nonpolar amino acids. Outline the

difference between fibrous and globular proteins.

Cytoplasmic Proteins

● Surrounded by water● Polar amino acids side chains fold to

the outside of the structure● Non-polar amino acid side chains are

protected on the inside of the structure

Membrane Proteins● How does the structure of the cell

membrane affect transmembrane proteins?

● Predict: Label hydrophilic heads of phospholipids, hydrophobic tails of phospholipids, polar amino acid region, and non-polar amino acid region.

Membrane Proteins● Within the amphipathic membrane● Polar amino acids in hydrophilic

region (inner/outer surface)● Nonpolar amino acids in hydrophobic

core● Polar amino acids lining channels so

charged/polar molecules can pass through

Fibrous & Globular Proteins

Fibrous Proteins Globular Proteins

Long and narrow Compact and rounded

Insoluble in water Soluble in water

Structure and support Enzymes and transport

Keratin Hemoglobin

Collagen Catalase