Chapter 7 Cell Structure and Function Unit 3

Cytology: the study of cells

Robert Hooke

Mid-1600s England Used microscope to observe living tissues Named chambers “cells”

Sketches from Micrographia

Anton van Leeuwenhoek Mid-1600s Holland Used hand lens microscope to observe pond water Observed microscopic life

Leeuwenhoek Microscope

Leeuwenhoek painting by Robert A. Thom This painting appeared in "Great Moments in Medicine" published by Parke Davis & Company, in 1966.

German cell biologists 1830s: Matthias Schleidan: concluded all plants made from cells 1830s: Theodor Schwann: concluded that all animals made from cells

Rudolph Virchow 1855 Germany New cells can only be produced from existing cells, confirmed by French scientist Louis Pasteur

Pasteur painting by Robert A. Thom This painting appeared in "Great Moments in Medicine" published by Parke Davis & Company, in 1966.

Lynn Margulis Organelles in larger, complex cells may have been free-living prokaryotic cells in the past.

Cell theory Cells are made from preexisting cells. Cells are the smallest units of life. All living things are made from at least one cell. Cells dividing

Properties of life Metabolism Homeostasis Growth & reproduction Cellular basis

Microscopy the use of microscopes to study cells Different types of microscopes –Light microscope –Transmission electron microscope –Scanning electron microscope

Light microscope visible light passes through specimen  glass lenses Sample of light microscope image (cork):

Transmission electron microscope TEM studies cellular interiors Sample of TEM image:

Scanning electron microscope SEM studies cellular surfaces Sample of SEM image:

Cellular basis of life Multicellular: organisms made up of more than one cell –Ex: protist, fungus, plant, animal Unicellular: organisms made up of only one cell –Ex: bacteria, protist, fungus

To be a cell… Plasma membrane: cell membrane, made of 2 layers of phospholipids Cytoplasm: carbohydrate and water based solution that suspends all internal parts of the cell Ribosomes: produces proteins DNA: genetic material made of nucleic acids

Two types of cells Prokaryote: bacteria, archaebacteria Eukaryote: protist, fungus, plant, animal

Prokaryotic cell No nucleus No organelles Small Simple Plasma membrane, ribosome, cytoplasm, DNA

Prokaryotic cell Capsule: durable outer covering that some bacteria have for protection against water, acids, and viruses Flagella: movement Cell wall: protective layer around plasma membrane Pili: anchoring and DNA exchange

Eukaryote Complex 4 basic components + organelles Organelles: small compartments that carry out specialized functions within a cell Many variations

Cytoskeleton Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion

Microtubules Internal support system (like mini- skeleton) Helps with muscle contractions

Smooth ER Endoplasmic reticulum produces lipids

Rough ER dotted with ribosomes, packages proteins made by ribosomes

Golgi apparatus (body) Modify, package, and sort protein packages for secretion, outside of cell

Mitochondria Organelle responsible for breaking down glucose molecules into ATP energy molecules

Chloroplast Organelle in plants and algae that produces sugar molecules by photosynthesis

Lysosome Organelle that produces enzymes to destroy foreign molecules and waste

Organelle that stores water, salt, food or waste Vacuole

Nucleus Stores DNA DNA helps to regulate protein production. Proteins regulate cellular activity.

Plant Cell Nuclear envelope Ribosome (attached) Ribosome (free) Smooth endoplasmic reticulum Nucleus Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrion Cell wall Cell Membrane Chloroplast Vacuole

Animal Cell Centrioles Nucleolus Nucleus Nuclear envelope Rough endoplasmic reticulum Golgi apparatus Smooth endoplasmic reticulum Mitochondrion Cell Membrane Ribosome (free) Ribosome (attached)