Cell Structure https://www.youtube.com/watch?v=gFuEo2ccTPA&feature=youtu.be

Measuring Cell Structures 1. Measurement taken by scientists are expressed in Metric Units. The official name of the metric system is International System of Measurements. The metric system is based on powers of 10.

fill in the metric chart. Unit Prefix Metric equivalent Real life equivalent Kilometer (km) Kilo- 1,000 m About 2/3 of a mile Meter (m) ------- 1 m (SI base Unit) A little more than a yard Centimeter (cm) Centi- 0.01 m About half the diameter of a penny Millimeter (mm) Milli- 0.001 m About the width of a pencil tip Micrometer (um) Micro- 0.000001 m About the length of a bacterial cell Nanometer (nm) Nano- 0.000000001 m About the length of a water molecule

Types of Microscopes 2. Electron Microscope 1. Compound Light Microscope The most powerful Light microscopes can magnify up to 2000X. 2. Electron Microscope Electron microscopes can magnify up to 200,000X. Transmission Electron Microscopes (TEM) reveal internal details. Scanning Electron Microscopes (SEM) shows 3-D images of surface.

Eyepiece Body Tube Revolving Nosepiece Objectives Arm Stage Clip Stage Course Adjustment Diaphragm Fine Adjustment Light Base

Eyepiece – lens closest to the viewers eye Body Tube – directs light from the objective to the eye Revolving nosepiece – hold the objectives Arm – holds the base of the microscope with the objectives and eyepiece Stage Clips – hold the slide in place Stage – supports the slide

Course Adjustment – used to bring an object into focus under LOW power Fine Adjustment – used to fine tune the focus under LOW and HIGH power Base – holds the light source, connects to the arm to hold the other parts of the microscope together Objective – more magnification of the objective Light source – light source Diaphragm – controls the amount of light that travels through the specimen

Levels of Organization Organism Organ System Organ Tissue Cells Atoms (Chemical)

I. Looking at Cells A. Scientists only became aware of cells after the invention of the microscope. 1. 1665:Robert Hooke observed cork cells and called them “little boxes”. 1675:Anton van Leeuwenhoek used a microscope and observed pond water. He discovered many living creatures.

Cell Theory A. Whose observations helped form the CELL THEORY? 1838- Mattias Schleiden concluded that cells make up every part of the Plant. 1839- Theodor Schwann concluded that animals are made up of cells. 1858- Rudolph Virchow determined that cells only come from other cells.

3 parts of the Cell Theory 1. All living things are made up of one or more cells. 2. Cells are the basic units of structure and function in organisms. 3. All cells arise from existing cells.

How many cells are our bodies made up of? 100 trillion CELL SIZE Small cells function more efficiently than large cells. How many cells are our bodies made up of? 100 trillion The advantage of cells being smaller is that substances that enter or leave a cell must cross that cell’s surface; if the cell is small they can exchange substances more readily than large ones.

Relationship between Surface area and Volume

Common Features of Cells Cell Membrane- outer boundary of cell Function- regulates what enters and leaves the cell Made up of- phospholipids and proteins Cytoplasm- fills the cell; cell parts are suspended in this Function- same as above Made up of- water and salts

Cytoskeleton- a system of microscopic fibers Function- provides framework, shape and support Made up of- protein fibers

Ribosomes- proteins are made here DNA- found in the nucleus Function- provides instructions for making proteins, regulates cell activities Made up of- nucleotides

Prokaryotes Smallest and simplest cells. Prokaryote- is a single-celled organism that LACKS a nucleus and other membrane bound organelles. They were the only organisms on Earth for 2 billion years. They are very simple and small. The familiar prokaryotes that cause infection and cause food to spoil are commonly called Bacteria.

Characteristics of Prokaryotes They can live everywhere. They can cause infection in humans and grow and divide very rapidly. Some do not need oxygen to survive. Some can make their own food. Prokaryotic cells have cytoplasm, cell wall, ribosomes, cell membrane & DNA (circular). Some have flagella for movement. Some prokaryotic cell walls are surrounded by a capsule that enables the cell to cling to almost anything.

. Flagellum Capsule DNA Plasma Membrane Cell Wall Ribsomes

Eukaryotic Cells A eukaryote is an organism whose cells have a nucleus. Organelle-parts of the cell that carry out specific activities Nucleus-internal compartment that holds DNA Function- controls cells activities

Cilia-short hair-like structures Function-used for movement Cytoskeleton- provides interior framework Function- support and shape of the cell Made up of- protein fibers: microfilaments, microtubules, intermediate fibers

Cell Membrane Cell Membrane- selective permeability (barrier) Made up of- phospholipids and proteins Draw a picture below of the Cell Membrane- Phospholipid and a Lipid bilayer:

Membrane Proteins Serve many roles including: as markers; as receptors to recognize and bind to substances; as enzymes; as transport proteins to move substances across the membrane

Cell Organelles The Nucleus Contains Hereditary information- DNA & RNA RNA- made in nucleus; used to make proteins DNA- wound tightly into chromosomes Humans have 46 chromosomes. Garden peas have 14 chromosomes.

Endoplasmic Reticulum-system of internal membranes Function- moves proteins and other substances through the cell Made up of- lipid bilayer & embedded proteins Rough ER- contains ribosomes Smooth ER- (lacks ribosomes)-makes lipids and breaks down toxins

C. Golgi Apparatus- flattened membrane- bound sac Function- package and distribution center (UPS) Made up of- proteins D. Lysosomes- vesicles that bud off of Golgi Apparatus Function-contains cell digestive enzymes They are present in plant cells just fewer than are found in animal cells.

E. Mitochondria- “MIGHTY MITOCHONDRIA”-site of cell metabolism (more mitochondria=more energy) Function-makes energy ATP for the cell Made up of- 2 membranes-inner is folded out and outside is smooth.

F. Centrosome and Centrioles Function- aid in cell division. Attaches to DNA to help divide it between the two cells Made up of- microfilaments, microtubules, protein They are not found in plants cell

Rough ER Smooth ER Nucleus Mitochondria Cytoskeleton Golgi Apparatus Cell Membrane Plasma Membrane Centrioles

F. Structures of Plant Cells-------- 3 structures found only in PLANT CELLS. 1. Cell Wall- surrounds the cell membrane Function- support & maintains shape of the cell Made up of- proteins, carbohydrates->cellulose 2. Chloroplasts- found in plant cells as well as algae Function-use light energy to make Carbohydrates ->glucose (sugar) Made up of- 2 membranes; has own DNA 3. Central vacuole- takes up most of a plant cell’s volume Function-stores water ,nutrients, wastes (when full cell wall is rigid)