© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. CELL STRUCTURE Chapter 3

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Introduction The cell is the basic unit of biological organization Basic composition –Protoplasm –Cell membrane –Organelles Eukaryotic vs. prokaryotic

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. HISTORY OF THE CELL THEORY

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. History of the Cell Theory Proposed in 1830s by Schleiden and Schwann Modern cell theory –Cells are smallest complete living things –All organisms are composed of one or more cells

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. History of the Cell Theory (cont’d.) Modern cell theory –Cells arise only from other cells –All existing cells are descendants of the first cells

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. ANATOMY OF A TYPICAL EUKARYOTIC CELL

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Introduction

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Cell Membrane Double phospholipid layer with embedded proteins

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Cell Membrane (cont’d.) Membrane transport: selectively permeable membrane –Osmosis –Protein channels –Active transport –Fluid mosaic model

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Cytoplasm of the Cell Mostly water with chemical compounds in solution or colloid –Solution vs. colloid Individual vs. clumped atoms or ions distributed in medium

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Cytoplasm of the Cell (cont’d.) Polar compounds go into solution Nonpolar compounds go into colloidal suspension

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Nucleus Control center of the cell Nuclear membrane has pores to allow substances passage Chromatin genetic material inside nucleoplasm Nucleolus: site of ribosome formation

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. The Mitochondria Powerhouses of the cell Cristae: inner folds where cellular respiration occurs Energy requirements of cell determine cristae number

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Lysosomes Digestive enzyme packages Function –Digest stored food –Maintenance and repair of organelles –Suicide agents for old or weak cells

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Endoplasmic Reticulum System of membranes that makes up channels Connects with outer nuclear and cell membranes Cisternae: sac-like or channel-like cavities

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Endoplasmic Reticulum (cont’d.) Rough ER –For protein synthesis –Attached ribosomes Smooth ER –Fat transport –Sex hormone synthesis

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Endoplasmic Reticulum (cont’d.) Golgi apparatus –Collection of flat saclike cisternae –Concentration and collection of cellular compounds –Storage warehouses of the cell –Carbohydrate synthesis site

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Ribosomes Distributed throughout cytoplasm Attached to rough endoplasmic reticulum No membrane covering Site of protein synthesis

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Ribosomes (cont’d.) Protein functions –Structure, enzymes or catalysts, immune response DNA contains the code for a particular protein –DNA found in nucleus

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Ribosomes (cont’d.) Transcription –Messenger RNA copies DNA code and leaves nucleus Translation –Transfer RNA picks up amino acids –Ribosomes link amino acids together

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Ribosomes (cont’d.)

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Centrioles Centrosome: two centrioles at right angles to each other –Composed of nine sets of triplet fibers Form spindle fibers during cell division Guide duplicated chromosomes to daughter cells

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Cilia and Flagella Hairlike protrusions from cell membrane Nine double fibrils around two single central fibrils Cilia move materials across cell surface Flagellum propels cell through a medium

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Animation – Anatomy of a Typical Cell Click Here to Play Anatomy of a Typical Cell Animation

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Plastids of Plant Cells Chloroplasts –Most common plastid –Photosynthesis: conversion of light into chemical energy –Granum Made of thylakoids Connected by lamella

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Plastids of Plant Cells (cont’d.) Chromoplasts: carotenoid pigments Leucoplasts: store food Cell membrane surrounded by cell wall

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Plastids of Plant Cells (cont’d.) Cell wall composed of cellulose –Cellulose Dietary fiber Synthesized by Golgi bodies Animal cells do not have cell walls

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Summary Discussed the modern cell theory and its origins Discussed the different parts of eukaryotic cells including the cell membrane, cytoplasm and organelles

© 2012 Delmar Cengage Learning. All Rights Reserved. May not be scanned, copied, duplicated, or posted to a publicly accessible website, in whole or in part. Summary (cont’d.) Discussed protein synthesis Described some of the differences between plant and animal cells