A Tour of the Cell Categories of Cells Features of Eukaryotic Cells o Membrane Structure o Nucleus and Ribosomes o Endoplasmic Reticulum (ER) o Golgi Apparatus o Lysosomes o Vacuoles Energy o Converting Organelles Chloroplasts o Mitochondria Cytoskeleton o Cell Shape o Cell Movement Structure Dictates Function, Even at the Cellular Level Erythrocytes Fibroblasts Epithelial cells (a) Cells that connect body parts, form linings, or transport gases Skeletal Muscle cell Smooth muscle cells (b) Cells that move organs and body parts Macrophage Fat cell (c) Cell that stores (d) Cell that nutrients fights disease Nerve cell (e) Cell that gathers information and control body functions (f) Cell of reproduction Sperm Why Are Cells So Small? Cell remain small because they cannot efficiently import nutrients or export waste materials across their membranes when they get too large. The Two Major Categories of Cells • The countless cells on earth fall into two categories: – Prokaryotic cells, such as bacteria – Eukaryotic cells, such as protist, fungal, plant, or animal cells Comparison of Prokaryotic and Eukaryotic Cells A Tour of the Cell Categories of Cells Features of Eukaryotic Cells o Membrane Structure o Nucleus and Ribosomes o Endoplasmic Reticulum (ER) o Golgi Apparatus o Lysosomes o Vacuoles Energy o Converting Organelles Chloroplasts o Mitochondria Cytoskeleton o Cell Shape o Cell Movement A Tour of the Cell Categories of Cells Features of Eukaryotic Cells o Membrane Structure o Nucleus and Ribosomes o Endoplasmic Reticulum (ER) o Golgi Apparatus o Lysosomes o Vacuoles Energy o Converting Organelles Chloroplasts o Mitochondria Cytoskeleton o Cell Shape o Cell Movement Anatomy of a Eukaryotic (Animal) Cell Chromatin Nucleolus Nuclear envelope Nucleus Smooth endoplasmic reticulum Mitochondrion Cytosol Lysosome Centrioles Centrosome matrix Cytoskeletal elements • Microtubule • Intermediate filaments Plasma membrane Rough endoplasmic reticulum Ribosomes Golgi apparatus Secretion being released from cell by exocytosis Peroxisome A Tour of the Cell Categories of Cells Features of Prokaryotic Cells Features of Eukaryotic Cells o Membrane Structure o Nucleus and Ribosomes o Endoplasmic Reticulum (ER) o Golgi Apparatus o Lysosomes o Vacuoles Energy o Converting Organelles Chloroplasts o Mitochondria Cytoskeleton o Cell Shape o Cell Movement Cell (Plasma) Membrane and Internal Membranes • The plasma membrane separates the living cell from its nonliving surroundings and regulates molecular traffic Animal cells have an extracellular matrix outside of their cells that hold them together in tissues and protects and supports them. A Tour of the Cell Categories of Cells Features of Prokaryotic Cells Features of Eukaryotic Cells o Membrane Structure o Nucleus and Ribosomes o Endoplasmic Reticulum (ER) o Golgi Apparatus o Lysosomes o Vacuoles Energy o Converting Organelles Chloroplasts o Mitochondria Cytoskeleton o Cell Shape o Cell Movement Focus on the Nucleus and Ribosomes Chromatin Nucleolus Nuclear envelope Nucleus Smooth endoplasmic reticulum Mitochondrion Cytosol Lysosome Centrioles Centrosome matrix Cytoskeletal elements • Microtubule • Intermediate filaments Plasma membrane Rough endoplasmic reticulum Ribosomes Golgi apparatus Secretion being released from cell by exocytosis Peroxisome The Nucleus: Information Storage and Control of the Cell • The nucleus is the library of the cell. • Chromosomes (books) within the nucleus store instructions on how to run the cell Ribosomes Make Proteins Using Genetic Instructions Copy of instructions from the nucleus A Tour of the Cell Categories of Cells Features of Prokaryotic Cells Features of Eukaryotic Cells o Membrane Structure o Nucleus and Ribosomes o Endoplasmic Reticulum (ER) o Golgi Apparatus o Lysosomes o Vacuoles Energy o Converting Organelles Chloroplasts o Mitochondria Cytoskeleton o Cell Shape o Cell Movement The Endoplasmic Reticulum • A protein synthesis site for exported proteins on the rough ER; acts as a “worktable” for ribosomes • A routing system for delivery of proteins (subway system) • A lipid synthesis factory in the smooth ER, including phospholipids for cell membrane • Variations of endoplasmic reticulum include sarcoplasmic reticulum in muscles cells (to store Ca+2) and Nissl bodies (rough ER) in neurons.