Cell Structure and Function New Textbook Chapter 2-Pg.38

The Discovery of the Cell Robert Hooke – first to see and identify cork “cells.” What is Robert Hooke famous for discovering? Cell Theory www.nerdscience.com 7-1

All living things are composed of cells. 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 www.nerdscience.com 7-1

Prokaryotes and Eukaryotes Nucleus – large membrane-enclosed structure that contains the cell’s genetic information. Prokaryotes – cells that do not contain nuclei. (Bacteria) Eukaryotes – cells that contain nuclei. (All other organisms) What is the difference from Prokaryotes and Eukaryotes? Nucleus www.nerdscience.com 7-1

Eukaryotic Cell Structure Organelles – structures in a cell that act like “little organs.” Cytoplasm – the jelly-like fluid where the organelles “float.” www.nerdscience.com 7-2

Inside the Nucleus Nuclear Envelope – membrane that surrounds the nucleus. Chromatin – consists of DNA wrapped around proteins. “Ball of string” Chromosomes – condensed string-like structure that forms from DNA just before the cell divides. Nucleolus – structure within the nucleus that makes ribosomes. www.nerdscience.com 7-2

Inside the Nucleus Nucleolus Chromatin Nuclear Envelope www.nerdscience.com 7-2

Ribosomes – made of RNA and protein. Make Proteins! Ribs=Meat=Protein www.nerdscience.com 7-2

Ribosomes Ribosome www.nerdscience.com 7-2

Endoplasmic Reticulum (ER) Endoplasmic reticulum – internal membrane system of the cell. Lipids, proteins, and other products are made here. Rough ER – has ribosomes Smooth ER – no ribosomes ER= Emergency Room=Keeps operations running smoothly. www.nerdscience.com 7-2

Endoplasmic Reticulum (ER) Rough ER Smooth ER www.nerdscience.com 7-2

Golgi Apparatus – modifies, sorts, and packages proteins. MAIL MAN www.nerdscience.com 7-2

Golgi Apparatus Golgi Apparatus www.nerdscience.com 7-2

Lysosomes – small organelles filled with enzymes. Digest molecules to be used by the cell. Lysol- Cleans www.nerdscience.com 7-2

Vacuoles – store materials. www.nerdscience.com 7-2

Vacuoles Vacuoles www.nerdscience.com 7-2

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

Mitochondria Mitochondria www.nerdscience.com 7-2

Chloroplasts Chloroplasts – organelles that capture energy from sunlight and convert it into chemical energy. (Photosynthesis) Found only in plants. www.nerdscience.com 7-2

Chloroplasts Chloroplast www.nerdscience.com 7-2

Centrioles – help organize cell division. Not found in plants. Cytoskeleton Cytoskeleton – helps cell to maintain shape, move, and move organelles. Centrioles – help organize cell division. Not found in plants. www.nerdscience.com 7-2

Cytoskeleton www.nerdscience.com 7-2

Cell Boundaries Cell membrane – thin, flexible membrane that surrounds the cell. All cells have this. Cell walls – rigid layer around the membrane found only in bacteria, fungi and plants. www.nerdscience.com 7-3

Controls what enters/leaves cell, provides support/protection. Cell Membrane Controls what enters/leaves cell, provides support/protection. Lipid Bilayer – double-layered sheet of phospholipids. Two layers! www.nerdscience.com 7-3

Diffusion and Osmosis Diffusion – movement of particles from an area of high to low concentration. Osmosis – the diffusion of water through a selectively permeable membrane. Water will move into/out of a cell to equalize concentrations. 7-3

Facilitated Diffusion and Active Transport Facilitated diffusion – when the plasma membrane “helps” particles pass through protein channels. No energy used. Active transport – when the plasma membrane uses energy to move particles against a concentration gradient. Uses Transport Proteins www.nerdscience.com 7-3

Facilitated Diffusion and Active Transport www.nerdscience.com 7-3

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