Cell Structure and Function

The “Discovery” of the Cell Robert Hooke – first to see and identify cork “cells.” 7-1

The Cell Theory Cell Theory: All living things are composed of cells. Cells are the basic units of structure and function in living things. New cells are produced from existing cells. Schleiden Schwann Virchow 7-1

Prokaryotes and Eukaryotes Nucleus – a membrane- enclosed structure that contains the cell’s genetic information, “control center” Prokaryotes – cells that do not contain nuclei. (Bacteria) Eukaryotes – cells that contain nuclei. (All other organisms) 7-1

“Command Center” Organelles Nuclear membrane – surrounds and protects the nucleus Chromosomes – condensed string-like structure that forms from DNA, contains cell information Nucleolus – structure within the nucleus that makes ribosomes

Inside the Nucleus Nuclear membrane Chromosomes Nucleolus 7-2

The Nucleus

Protection & Support Organelles Organelles – structures in a cell that act like “little organs.” Cytoplasm – the gel-like fluid where the organelles “float.” 7-2

Protection & Support Organelles Cytoskeleton – helps cell to maintain shape, move, and move organelles

The Cytoplasm 7-2

Cell Boundaries Cell membrane – thin, flexible membrane that surrounds the cell. Controls what enters/leaves cell, provides support/protection. Cell walls – rigid layer around the membrane found only in bacteria, fungi and plants

Cell Membrane 7-3

Energy Processing Organelles Chloroplasts – organelles that capture energy from sunlight and convert it into chemical energy  Photosynthesis –Found only in plants

Chloroplasts Chloroplast 7-2

Energy Processing Organelles Mitochondria – organelle that converts chemical energy stored in food into compounds that are more convenient for the cell to use. –“Powerhouse of the Cell!” 7-2

Mitochondria 7-2

The Mitochondria

Manufacturing Organelles Ribosomes – made of RNA and protein. Make Proteins! 7-2

Ribosomes Ribosome 7-2

Transport Organelles Endoplasmic reticulum – internal membrane system of the cell. –Lipids, proteins, and other products are made here. –Rough ER – has ribosomes –Smooth ER – no ribosomes 7-2

Endoplasmic Reticulum (ER) Rough ER with ribosomes Smooth ER no ribosomes 7-2

Endoplasmic Reticulum

Processing Organelles Golgi Body – modifies, sorts, and packages proteins

Golgi Body 7-2

The Golgi Body

Storage Organelles Vacuoles – store materials

Vacuoles 7-2

Specialized Plant Organelles

Recycling Organelles Lysosomes – small organelles filled with enzymes. –Digest molecules to be used by the cell. 7-2

Lysosomes

Organization in Multicellular Organisms Tissues Organs Organ System Organism Cells 7-4