Lecture 3Lecture 3

BIOL L100 BIOL L100 Indiana University SoutheastIndiana University Southeast

David Partin, InstructorDavid Partin, Instructor

Today’s Plan…Today’s Plan…

Lecture: Cell Structure & Function Lecture: Cell Structure & Function (Ch4-5)(Ch4-5)

Video clipVideo clip One-Minute PaperOne-Minute Paper LabLab

The CellThe Cell

A cell is the smallest unit of A cell is the smallest unit of livingliving matter. matter.

Don’t confuse this with: atom, Don’t confuse this with: atom, element, proton, etc.element, proton, etc.

Cell TheoryCell Theory

““Theory” is not a casual term in Theory” is not a casual term in science.science.

Tested innumerable times with Tested innumerable times with consistent results.consistent results.

Universally acceptedUniversally accepted One of the most basic, fundamental One of the most basic, fundamental

concepts in the foundation of biology.concepts in the foundation of biology.

Cell TheoryCell Theory

1800s; several scientists working 1800s; several scientists working independently had similar resultsindependently had similar results

1. All organisms are made of cells.1. All organisms are made of cells. 2. A cell is the structural & function unit 2. A cell is the structural & function unit

of organs.of organs. 3. All cells come from pre-existing cells.3. All cells come from pre-existing cells. 4. Cells are capable of self-reproduction.4. Cells are capable of self-reproduction.

Cell SizeCell Size

Types of OrganismsTypes of Organisms

Unicellular organismsUnicellular organisms Bacteria, Protists, etc.Bacteria, Protists, etc.

Multicellular organismsMulticellular organisms PlantsPlants AnimalsAnimals

Muscles, skin, nerves, liver, digestive, bones, Muscles, skin, nerves, liver, digestive, bones, blood, immune system, lungs, etc.blood, immune system, lungs, etc.

Cell Structure & FunctionCell Structure & Function

Bacteria

Cell Structure & FunctionCell Structure & FunctionTypical Plant

Cell Structure & FunctionCell Structure & FunctionGeneric Animal Cell

Cellular OrganellesCellular Organelles CytoplasmCytoplasm NucleusNucleus

Chromosomes, nuclear Chromosomes, nuclear envelope, nuclear envelope, nuclear pores, nucleoluspores, nucleolus

RibosomesRibosomes Endoplasmic reticulum Endoplasmic reticulum

(smooth & rough)(smooth & rough) Golgi ApparatusGolgi Apparatus LysosomesLysosomes

VesiclesVesicles PeroxisomesPeroxisomes VacuolesVacuoles ChloroplastChloroplast MitochondriaMitochondria CytoskeletonCytoskeleton CentriolesCentrioles Cilia, FlagellaCilia, Flagella Plasma MembranePlasma Membrane

““Cell City” website: Cell City” website: http://www.open2.net/science/cellcity/cellcity.html

Nucleus: DNA stored here.Nucleus: DNA stored here.The Control CenterThe Control Center Nuclear

envelope: membrane surrounding the nucleus

Nuclear pores: open portals of communication between the nucleus & cytoplasm

Chromatin: condensed DNA

Chromosome: very tightly packed DNA

Nucleolus: dense region of chromatin

RibosomesRibosomes: protein factories: protein factoriesRough ERRough ER: make proteins (studded with : make proteins (studded with

ribosomes)ribosomes)Smooth ERSmooth ER: make lipids, modify proteins made in : make lipids, modify proteins made in

RERRER

Protein Production

1-receives proteins & lipids in membrane-bound vesicles 1-receives proteins & lipids in membrane-bound vesicles from ER.from ER.2-modifies those proteins & lipids.2-modifies those proteins & lipids.3-sorts and ships the proteins & lipids away in membrane-3-sorts and ships the proteins & lipids away in membrane-bound vesicles.bound vesicles.

Mitochondria & Chloroplast:Power Stations of the cell

The Endosymbiont Hypothesis

Cytoskeleton: provides structure and Support for the cell. Also provides a Scaffolding for vesicle transportation.

Specialized variations of the cytoskeleton (seen only in specific cells).

Cytoskeleton is made of these proteins…

Cell membrane (plasma membrane)

Plasma membrane is made up of

1. Mostly phospholipids

2. Proteins

3. Cholesterol

4. carbohydrates

Diffusion: movement of a substance from an

area of higher concentration to an

area of lower concentration.

Oxygen and carbon dioxide DIFFUSE across the walls of blood vessels and the lining of the lungs.

Diffusion

Exocytosis = leaving the cell

Endocytosis

Time for recess!Time for recess!

What’s next?What’s next? Video clipVideo clip ““one minute paper”one minute paper” LabLab

Overview of today’s lab…Overview of today’s lab…

3 eggs, each in a different solution3 eggs, each in a different solution Distilled waterDistilled water 20% sucrose20% sucrose 40% sucrose40% sucrose

Weigh each egg before beginning the Weigh each egg before beginning the experiment, then at 20 minute intervals. experiment, then at 20 minute intervals.

Eggs represent Eggs represent cellscells. We will use these . We will use these results to explain concepts in next results to explain concepts in next week’s classes.week’s classes.

Preparation for next class:Preparation for next class:

Topics: Metabolism and Topics: Metabolism and PhotosynthesisPhotosynthesis

Skim/Read Ch. 6-7Skim/Read Ch. 6-7 Focus on: Ch 6, sections 6.1, 6.2, 6.3 & Focus on: Ch 6, sections 6.1, 6.2, 6.3 &

allall section summaries, including 6.4 section summaries, including 6.4 summarysummary

Focus on: Ch 7, section 7.1, and p.119Focus on: Ch 7, section 7.1, and p.119 Look for online quizzes. Look for online quizzes.