Cell Structure and FunctionCell Structure and Function

Biology 2121 Biology 2121 Chapter 3Chapter 3

• Organelles – specialized structures

• Cytoplasm • Cytosol - collodial mixture • Inclusions

• Important Organelles • Mitochondria – ATP synthesis • Ribosomes – protein synthesis • Peroxisomes

• Catalase and oxidase enzymes – detoxification • Centrioles – animal cell mitosis • Cytoskeleton – support

• Endomembrane System

• Nucleus• DNA-Chromosomes and genes

• Rough Endoplasmic Reticulum • Ribosomes and modification of proteins

• Golgi Apparatus• Modification of proteins – export or import

• Lysosomes

• Fluid Mosaic Model – Selectively Permeable

• Phospholipid Bilayer• Polar Heads – face water

• Hydrophilic • Nonpolar Fatty acid tails

• Hydrophobic

• Proteins • Transmembrane – Integral• Peripheral

• Cholesterol

• Tight Junctions• Epithelial cells – skin and digestive tract• Impermeable junctions

• Gap Junctions- “nexus”• Communication • Transmembrane proteins – connexions • Heart and smooth muscle

The Role of The Role of Proteins Proteins • Transport

• Intercellular Joining

• Cell to Cell Recognition• Glycoproteins

• Attachment site for Extracellular Matrix and Cytoskeleton