Power Point Presentation to Accompany 2010 Delmar Cengage

Power. Point Presentation to Accompany © 2010 Delmar, Cengage Learning

Chapter 3 Cell Structure © 2010 Delmar, Cengage Learning 2

Introduction • The cell is the basic unit of biological organization • Basic composition – Protoplasm – Cell membrane – Organelles • Eukaryotic vs. prokaryotic © 2010 Delmar, Cengage Learning 3

History of the Cell Theory © 2010 Delmar, Cengage Learning 4

History of the Cell Theory • Proposed in 1830 s by Schleiden and Schwann • Modern cell theory – Cells are smallest complete living things – All organisms are composed of one or more cells – Cells arise only from other cells – All existing cells are descendants of the first cells © 2010 Delmar, Cengage Learning 5

Anatomy of a Typical Eucaryotic Cell © 2010 Delmar, Cengage Learning 6

Introduction © 2010 Delmar, Cengage Learning 7

The Cell Membrane • Double phospholipid layer with embedded proteins • Membrane transport: selectively permeable membrane – Osmosis – Protein channels – Active transport – Fluid mosaic model © 2010 Delmar, Cengage Learning 8

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 • Polar compounds go into solution • Nonpolar compounds go into colloidal suspension © 2010 Delmar, Cengage Learning 9

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 © 2010 Delmar, Cengage Learning 10

The Mitochondria • Powerhouses of the cell • Cristae: inner folds where cellular respiration occurs • Energy requirements of cell determine cristae number © 2010 Delmar, Cengage Learning 11

Lysosomes • Digestive enzyme packages • Function – Digest stored food – Maintenance and repair of organelles – Suicide agents for old or weak cells © 2010 Delmar, Cengage Learning 12

Endoplasmic Reticulum • System of membranes that makes up channels • Connects with outer nuclear and cell membranes • Cisternae: sac-like or channel-like cavities © 2010 Delmar, Cengage Learning 13

Endoplasmic Reticulum (cont’d. ) • Rough ER – For protein synthesis – Attached ribosomes • Smooth ER – Fat transport – Sex hormone synthesis © 2010 Delmar, Cengage Learning 14

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 © 2010 Delmar, Cengage Learning 15

Ribosomes • • Distributed throughout cytoplasm Attached to rough endoplasmic reticulum No membrane covering Site of protein synthesis © 2010 Delmar, Cengage Learning 16

Ribosomes (cont’d. ) • Protein functions – Structure, enzymes or catalysts, immune response • DNA contains the code for a particular protein – DNA found in nucleus © 2010 Delmar, Cengage Learning 17

Ribosomes (cont’d. ) • Transcription – Messenger RNA copies DNA code and leaves nucleus • Translation – Transfer RNA picks up amino acids – Ribosomes link amino acids together © 2010 Delmar, Cengage Learning 18

Ribosomes (cont’d. ) © 2010 Delmar, Cengage Learning 19

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 © 2010 Delmar, Cengage Learning 20

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 © 2010 Delmar, Cengage Learning 21

Animation – Anatomy of a Typical Cell • [Insert typical cell. swf] © 2010 Delmar, Cengage Learning 22

Plastids of Plant Cells • Chloroplasts – Most common plastid – Photosynthesis: conversion of light into chemical energy – Granum • Made of thylakoids • Connected by lamella • Chromoplasts: carotenoid pigments • Leukoplasts: store food © 2010 Delmar, Cengage Learning 23

Plastids of Plant Cells (cont’d. ) • Cell membrane surrounded by cell wall • Cell wall composed of cellulose – Cellulose • Dietary fiber • Synthesized by Golgi bodies • Animal cells do not have cell walls © 2010 Delmar, Cengage Learning 24

Summary • Discussed the modern cell theory and its origins • Discussed the different parts of eukaryotic cells including the cell membrane, cytoplasm and organelles • Discussed protein synthesis • Described some of the differences between plant and animal cells © 2010 Delmar, Cengage Learning 25