• Always carry with 2 hands• Only use lens paper for cleaning• Do not force knobs• Always store covered• Keep objects clear of desk and cords

Eyepiece

Body Tube

Revolving NosepieceArm

Objective Lens

StageStage Clips

Coarse Focus

Fine Focus

Base

Diaphragm

Light

Always carry a microscope with one hand holding the arm and one hand under the base.

• Place the Slide on the Microscope

• Use Stage Clips • Click Nosepiece to the lowest

(shortest) setting• Look into the Eyepiece• Use the Coarse Focus

What’s my power?To calculate the power of magnification, multiply the power of the ocular lens by the power of the objective.

What are the powers of magnification for each of

the objectives we have on our microscopes?

Comparing Powers of Magnification

We can see better details with higher the powers of magnification, but we cannot see as much of the image.

Which of these images would be viewed at a higher power of

magnification?

Chapter 1

Cells: The

Basic Units of

LifeSections 1-3Pages 2-27

Cells and the Cell Theory

• Robert Hooke in 1665 built a microscope

• Looked at cork from trees and saw tiny “boxes”, he called them cells (little rooms)

• Hooke spent most time looking at plants and fungi because they we easy to see since the had cell walls

Finding Cells in other Organisms

• Anton van Leeuwenhoek in 1673 built a microscope

• He examined pond scum and saw small organisms in the water

• Named the organisms animalcules “little animals”

• Today we call these “little animals” protists

Finding Cells in other Organisms

• Leeuwenhoek also examined animal blood

• Noticed differences in the shape of animal blood cells (humans had round/flat cells while fish, birds and frogs were oval)

• 1st person to see bacteria• Discovered yeast to make

bread dough rise are single cell organisms

Cell Theory…200 years later

• Schwann wrote the first two parts of the cell theory (1839)

1. All organisms are made of one or more cells.

2. The cell is the basic unit of all living things.

• Virchow added the third part of theory (1858)

3. All cells come from existing cells.

Cell Size

• Most cells are very small because if a cell’s volume gets too large, the cell’s surface area will not be able to take in enough nutrients or get rid of wastes fast enough to keep cells alive.

• Use the surface area-to –volume ratio=

Surface area/volume

Example: page 6

Parts of a cell-Cell Membrane

• All cells are surrounded by a cell membrane

• Protective layer and acts as a barrier

• Controls materials that go in and out of cell

Inside the Cell- Cytoplasm

Organelles

• Organelles are structures within a cell that perform specific functions for the cell

Two Kinds of Cells

Prokaryotes• Has cell membrane,

organelles, cytoplasm, and DNA

• NO NUCLEUS• 2 types: eubacteria and

archaebacteria

Eukaryotic• Has cell membrane,

organelles, cytoplasm, and DNA

• HAS A NUCLEUS

Genetic Material• All cells contain DNA

(deoxyribonucleic acid)• DNA carries information to

make new cells and controls the activities of a cell

• In some cells, DNA is enclosed in the nucleus

• The nucleus is a membrane bound organelle that contains the cell’s DNA and that has a role in process such as growth, metabolism and reproduction. (eukaryotic cells only)

Eubacteria

• Most common prokaryote

• Called bacteria• No nucleus, has DNA• Contain ribosomes• Strong web like cell wall• Bacteria can be in

water, soil and living on or inside you!

Archaebacteria

• Called Archaea • Similar to bacteria

except have different ribosomes

• Three types: 1. heat loving 2. salt loving3. methane making

Eukaryotic Cells and Eukaryotes

• Larger than prokaryotic cells

• Have a nucleus and membrane bound organelles

• Multicellular (many cells) like animals and plants

Cell Wall

• Some eukaryotic cells have cell wall

• Cell Wall: rigid structure that gives support to a cell

• Plants and algae have a cell wall which is made of cellulose (complex sugar humans cant digest…FIBER)

– Protect and support the enclosed substances (protoplasm)

– Resist entry of excess water into the cell

– Give shape to the cell

• Cell wall

Cell Wall in a Plant Cell

– Fungi (yeast and mushrooms)

– Chitin – Large empty spaces present between cellulose fibers

freely permeable

• Cell wall

Cell Wall in a Plant Cell

Cell Membrane

• All cells have cell membrane, outermost structure in cells that lack a cell wall

• Protective barrier• Contains proteins, lipids

and phospholipids (fat and cholesterol)

• Lipids are a group of compounds that do not dissolve in water

Cell Membrane• Phospholipids- a lipid that

contains a phosphorus. • Lipids are water fearing or

hydrophobic• The lipid ends of the

phospholipids are the inner part of the cell membrane

• The phosphorus ends are water loving or hydrophilic

• The phosphorus ends form the outer part of the cell membrane

Cell Membrane’s 2 Main Functions

• Encloses the cell and separates and protects the cell’s contents from the cell’s environment

• It also controls the movement of materials into and out of the cell

Cytoskeleton

• A web of proteins in the cytoplasm

• Acts as muscle and a skeleton (support and structure)

• Can help cell move• Made of 3 types of

proteins (one is a hollow tube, the other two are long and stringy)

Nucleus• Large organelle in eukaryotic cells• Contains cell’s DNA or genetic

material• DNA contains information on

how to make a cell’s protein• Covered by two membranes• Materials pass through this

double membrane through pores• Most cells have a nucleolus in the

center of the nucleus (which stores materials that will be used to make ribosomes)

Ribosomes

• Organelles that make proteins

• Smallest of organelles• Float freely or are attached

to other organelles• Proteins are made within

the ribosomes• Proteins are made of amino

acids (20 of them)• All cells need protein to live

Proteins - Structure

• Proteins made up of small molecules called amino acids

• There are 20 common amino acids

• How the amino acids combine and their order determine the type of protein made

Proteins - Function

• Much of the structure of a cell is made of protein, including the organelles inside.

• Proteins can be enzymes

• Enzymes are a type of protein that speeds up a chemical reaction

Nucleic Acids

• These are very long organic molecules made of Carbon, Oxygen, Hydrogen, Nitrogen and Phosphorus.

• Two kinds: RNA and DNA

• DNA- genetic material• RNA- protein synthesis

Endoplasmic Reticulum

• A system of folded membranes in which proteins, lipids and other materials are made.

• Internal delivery system of the cell

• Rough ER: covered in ribosomes, makes proteins

• Smooth ER: makes lipids and breaks down toxic materials

Mitochondria (Mitochondrion)

• POWER SOURCE of cell• Breaks down sugar for

energy• Covered by two

membranes• Have their own DNA• Can divide within a cell• Most eukaryotic cells

have mitochondria

Mitochondria

• Energy released by mitochondria is stored in a substance called ATP (adenosine triphosphate)

• ATP is used to do “work”• ATP made at several

places in a cell but most made in the mitochondria

Chloroplasts• Animal cells can not make their

own food but plants and algae can using the chloroplasts

• Photosynthesis (sun+CO2+H2O=sugar+O2)sugar made helps make ATP in mitochondria

• Chloroplasts have two membranes and their own DNA

• Green in color because of chlorophyll (green pigment) inside

Golgi Complex

• Processes, Packages and Distributes proteins

• Named after discoverer (Camillo Golgi)

• Looks like ER• Creates “bubble” or a

vesicle (small sac) that transports materials within the cell

Cellular Digestion

• Lysosomes: responsible for digestion

1. They destroy worn out or damages organelles

2. Get rid of waste materials

3. Protect cell wall from invaders

Vacuoles

• Large vesicle• In plant and fungal cells• Some act like lysosomes• Some store water

Different kinds of plant cells

Onion Epidermal Cells

Root Hair Cell

root hair

Guard Cells

Different kinds of animal cells

white blood cell

red blood cell

cheek cells

sperm

nerve cell

muscle cell

Amoeba

Paramecium

Similarities between plant cells and animal cells

Both have a cell membrane surrounding the cytoplasm

Both have a nucleus

Both contain mitochondria

Differences between plant cells and animal cells

Animal cells Plant cells

Relatively smaller in

sizeIrregular

shapeNo cell wall

Relatively larger in size

Regular shape

Cell wall present

Animal cells Plant cells

Vacuole small or absent

Glycogen granules as food

storeNucleus at the

centre

Large central vacuole

Starch granules as food store

Nucleus near cell wall

Differences between plant cells and animal cells

Benefits of Being Multicellular

• Larger Size: larger than a single celled organism. Larger have less predators and have more choices of prey.

• Longer Life: Not limited to any single cell.

• Specialization: More efficient since each cell has a job.

Cells Working TogetherTissue- group of cells working together to perform a specific job

Animals have 4 types of tissue:

1. Nerve tissue2. Muscle tissue3. Connective tissue4. Protective tissue

Plants have 3 types of tissue:1. Transport tissue- moves

water and nutrients through plant

2. Protective tissue- covers the plant, retain water and protects from damage

3. Ground tissue- where photosynthesis takes place

Organ• Different tissues group together to carry out specialized functions–Heart : consists of muscles, nervous tissue and blood vessels

–Leaf : consists of epidermis, mesophyll and vascular tissue

Stoma

Air Space

Spongy Mesophyll Cell

Chloroplast

The Structures of a Leaf

Palisade Mesophyll Cell

The Structures of a Heart

System• Several organs and tissues work together to carry out a particular set of functions in a co-ordinated way–Human : digestive, respiratory, excretory, circulatory and reproductive systems

–Plant : root and shoot systems

Level of Organization

cells (e.g. muscle cells, nerve cells)

tissues (e.g. muscle, epithelium)

organs (e.g. heart, lungs, stomach)

systems (e.g. circulatory system)

organisms (e.g. man)

Structure and Function’s relationship

• Structure: arrangement of parts in an organism

• Function: the job each part does within

• Example-Alveoli function-contain

and exchange gasesAlveoli structure- enables

them to perform a function

Cell Fun!!!!• http://crescentok.com/staff/jaskew/isr/biology/comic/page1.htm• http://www.sheppardsoftware.com/health/anatomy/cell/index.htm• http://www.biology4kids.com/files/cell_main.html• http://learn.genetics.utah.edu/content/begin/cells/• http://www.biologycorner.com/bio1/diffusion.html• http://www.cellsalive.com/• http://biology.clc.uc.edu/courses/bio104/cellresp.htm• http://www.eurekascience.com/index.htm• http://www.johnkyrk.com/CellIndex.html• http://www.ibiblio.org/virtualcell/index.htm• http://www.biology.arizona.edu/cell_bio/tutorials/pev/page2.html Pro and Eu• http://www.harcourtschool.com/activity/cell/cell.html• http://www.courses.fas.harvard.edu/~biotext/animations/TRANSLATE20b.swf• http://www.wisc-online.com/objects/ViewObject.aspx?ID=AP1302 protein synthesis • http://www.brookscole.com/chemistry_d/templates/student_resources/shared_resources/anima

tions/protein_synthesis/protein_synthesis.html• http://www.wiley.com/college/boyer/0470003790/animations/replication/replication.htm• http://www.nobelprize.org/educational/medicine/2001/

Plants

• http://www2.estrellamountain.edu/faculty/farabee/biobk/BioBookPLANTANAT.html

• http://www.softschools.com/science/plants/flower_anatomy.jsp

• http://www.amnh.org/learn/biodiversity_counts/ident_help/Parts_Plants/parts_of_flower.htm

• http://www.phschool.com/science/biology_place/biocoach/photosynth/leaf.html