Structure and Function of the Cell Chapter 4
4.1 Discovering the cell… 1665 – Hooke looked at plants under the microscope and saw little boxes – –He named them “cells” 1673 – Van Leeuwenhoek was the first to see living cells
Fast Forward…150 years! Schleiden – all plants are composed of cells – all animals are composed of cells Schwann – all animals are composed of cells – cells come only from other cells Virchow – cells come only from other cells These three scientists’ work lead to the modern CELL THEORY
The Cell Theory 1. All living things are composed of cells 2. Cells are the basic unit of an organism 3. Cells only come from the reproduction of preexisting cells.
Cell Diversity Red Blood Cells Bacterial Cells Parasitic CellUlcer causing bacteria cells
Your body has over 200 different types of cells!
Cell Size Most cells are microscopic Cell size is limited by the surface area to volume ratio
Cell Shape Shape is determined by the function of the cell
Internal Organization Prokaryotic Vs. Eukaryotic Cells “Before Nucleus” No Nucleus or Membrane organelles Single cell organisms “True Nucleus” Yes Nucleus and Membrane organelles Multicellular and single Cell organisms
Surface Area to Volume Ratio Surface Area : L x W x # of sides Volume: L x W x H Ratio : surface area/volume
Now you try…. 1. Obtain a copy of the lab: Modeling Cells: Surface Area to Volume AND box paper 2. Cut out boxes and tape them together (3 boxes total) 3. Complete lab worksheet about surface area to volume ratio
All Eukaryotic Cells Have… 1. A cell membrane 2. A nucleus 3. Other organelles
Parts of the Eukaryotic Cell The structures are determined by the functions of each part
1. Cell Membrane Function: outer layer of a cell that allow substances into and out of the cell Selectively permeable – allows only certain things to cross the membrane
Parts of the Membrane Membrane Lipids – –Phospholipids arranged due to their hydrophobic and hydrophilic ends – –Lipid bilayer – –Steroid (cholesterol) embedded within
Parts of the Membrane (cont) Membrane Proteins –Peripheral proteins – attached to either side of the cell membrane –Integral proteins – embedded within the cell membrane and extends out on both sides
Fluid Mosaic Model Membrane behaves like a liquid –Lateral movement of lipids and proteins Mosaic – changing pattern of proteins and lipids in the membrane
Organelles Organelles “Mini organs” of the cell Each organelle has its own structure and function All cells have different types and numbers of organelles
Nucleus Nucleus Function: to store the hereditary information of the cell (DNA) and to control the cell Contains: nuclear envelope, nuclear pores, nucleolus, and chromatin (chromosomes)
Mitochondria Function: makes ATP “Powerhouse of the Cell”
Rough Endoplasmic Reticulum Function: Makes proteins, glycoproteins, and membranes for export out of the cell Covered in ribosomes
Smooth Endoplasmic Reticulum Function: Makes lipids, metabolizes carbohydrates, and detoxification center for the cell
Ribosomes Function: Protein synthesis Attached to E.R. or free in cytoplasm Made in nucleus and completed in cytoplasm
Golgi Apparatus Function: Manufacturing, warehousing, sorting, and shipping materials out of the cell
Lysosomes Function: Digests (breaks down) macromolecules the are in the cell, such as proteins and carbs. Also breaks down dead cells
Peroxisomes Function: Breaks down fatty acids Detoxification center in liver cells
Cytoskeleton Function: Support system of the cell, aid in movement within the cell 3 Structural Types: microtubules microtubules microfilaments microfilaments intermediate filaments intermediate filaments
Cytoplasm Function: Holds organelles in the cell Site of all chemical reactions in cell
Cilia and Flagella Function: Locomotion and movement of materials around the cell Animal cells only
Cell Wall Function: Protects the cell, gives the cell shape and structural support Plant cells
Chloroplasts Function: Photosynthesis Makes energy from the sun In plant cells
Central Vacuole Function: Stores materials especially water and waste products In plant cells