CHAPTER 7: CHAPTER 7:

CELL STRUCTURE CELL STRUCTURE AND AND

FUNCTIONFUNCTION

California State Standards1. Cell biologya. Cells are enclosed in semipermeable

membranes that regulate their interactions with their surroundings

c. Know prokaryotic cell differ from eukaryotic cellse. Know the role of endoplasmic reticulum and

golgi apparatus in the secretion of proteinsg. Students know the role of mitochondria in

making stored chemical-bond energy available to cells

j. Students know how eukaryotic cells are given shape and internal organization by a cytoskeleton or cell wall or both.

7-1 Life Is Cellular

A. The Discovery of the Cell

1. Early Microscopes • Robert Hooke-

• Anton van Leeuwenhoek-

2. The Cell Theory• Mathias Schleiden-

• Theodor Schwann-

• Rudolf Virchow-

Used compound microscope to look at a slice of cork

Observed tiny living things in pond water

Concluded all plants are made of cells

Stated all animals are made of cells

Concluded new cells come from existing cells

Cell Theory:

All living things are composed of _____

Cells are the basic units of structure and function in living things

New cells are produced from ____________

cells

Existing cells

B. Exploring the Cell1. Electron Microscope (TEM & SEM) -Specimen placed in a vacuumhttp://www.mos.org/sln/sem/

2. Scanning Probe Microscope -1990 development of fine probe microscope -operates in _______________ -can even show samples in solution

ordinary air

C. Prokaryotes and Eukaryotes• cells vary in size from _________________-

___________________• viruses are not cells

0.2 micrometers

1000 micrometers

Cell membrane

Cell membrane

CytoplasmNucleus

Organelles

Cytoplasm

Eukaryotic cell

Prokaryotic cell

Prokaryotes Common to Both Eukaryotes pro=__________

karyote= kernel (nucleus)

generally smaller less complicated no

Ex: Kingdom Monera - Eubacteria - Archaea

contain __________

Eu= ___________

Karyote=kernel (nucleus)

Generally larger Contain

membrane bound organelles (“little organs”)

Ex:

before true

Membrane bound organelles

Plants, animals, fungi, and protists

DNA

Cell membrane

Eukaryotic Cell vs. Prokaryotic cell

Warm-upWarm-upSection 7-1 Section 7-1

1. Name 3 scientists and their contribution to science.

2. What is the cell theory?

3. What are the characteristics of prokaryotes and eukaryotes. Use the “thinking visually” box on page 173 to answer this question.

Prokaryotes Eukaryotes

Cell membraneContain DNA

ribosomes

NucleusEndoplasmic reticulum

Golgi apparatusLysosomesVacuoles

MitochondriaCytoskeleton

Animal Cells Plant Cells

CentriolesLysosomes

Cell membraneRibosomes

NucleusEndoplasmic reticulum

Golgi apparatusVacuoles

MitochondriaCytoskeleton

Cell WallChloroplasts

Central Vacuole

Section 7-2

Venn Diagrams7-2 Eukaryotic Cell Structure(chart)

Plant Cell

Nuclearenvelope

Ribosome(attached)

Ribosome(free)

Smooth endoplasmicreticulum

Nucleus

Rough endoplasmic reticulum

Nucleolus

Golgi apparatus

Mitochondrion

Cell wall

CellMembrane

Chloroplast

Vacuole

Section 7-2

artists rendition of the plant cell

artists rendition of an animal cell

Animal cell

Cell membrane

Endoplasmicreticulum

Microtubule

Microfilament

Ribosomes Mitochondrion

Warm-upWarm-upSection 7-2Section 7-2

1.1. Compare and contrast plant and animal Compare and contrast plant and animal cells. Are they prokaryotic or eukaryotic?cells. Are they prokaryotic or eukaryotic?

2.2. Eukaryotic cells maintain shape and Eukaryotic cells maintain shape and internal organization with ….?internal organization with ….?

3.3. What is the function of the nucleus?What is the function of the nucleus?

4.4. Where is chemical energy from food Where is chemical energy from food converted to useable energy?converted to useable energy?

5.5. Where is light energy converted to Where is light energy converted to chemical energy in plants? What is this chemical energy in plants? What is this process called?process called?

7-3 Cell Boundaries A. Cell Membrane

• Regulates what ___________ and __________ the cell

• Provides • Composed of a ______________

• __________________ are embedded in the bilayer;

• _________________ are attached to some of the proteins; allows cells to __________ one another.

enters leaves

protection and supportlipid bilayer

Protein moleculesform channels and pumps to move material across the cell membrane.

Carbohydratesidentify

Outsideof cell

Insideof cell(cytoplasm)

Cellmembrane

Proteins

Proteinchannel Lipid bilayer

Carbohydratechains

CELL MEMBRANE“FLUID MOSAIC”

“transport”

“ID tags”

“Phospholipids”

B. Cell Walls• Found in

• Cell walls are porous enough to allow

• Main function is to provide

• Plant cell walls made of __________ (carbohydrate fiber)

plants, algae, fungi and many prokaryotes

water, oxygen, carbon dioxide easily

support and protection for the cell

cellulose

C. Diffusion Through Cell Boundaries•All living cells exists in a

•Cell membranes regulate

•Cell membranes are _____________________ (aka: _______________)

•If substances can pass, then the cell membrane =

•If substances cannot pass, then the cell membrane=

liquid environment.

the movement of molecules in and out of the cell.

selectively permeablesemipermeable

impermeable

Permeable

1. Measuring Concentration• Cytoplasm=

• Concentration=

• Example:12g salt/3L H2O=

60g salt/3L H2O=

• Concentration gradient=

Water and other substances between the cell membrane and the nucleus.

mass of solute/volume of solution

4 g/L

20 g/L 5X moreconcentrated

unequal distribution of particles

2. Diffusion• Particles constantly

• Particles move from a _____ concentration _____ a ____ concentration (with the concentration gradient); process is known as _________

• Diffusion continues until

• Equilibrium =

Diffusion depends upon random particle movements, substances diffuse across membranes ______ requiring the cell to use _______

•

collide and spread out randomly in solution

high to low

diffusion

equilibrium is reached

When particles are evenly distributed in solution

withoutenergy

The movement of particles will continue to move equally across the cell membrane to maintain equilibrium.

D. Osmosis• Osmosis =

Selectively permeable membrane

BeforeOsmosis

AfterOsmosis

H2O passes easily across most membranes

The diffusion of water through a selectively permeable membrane

watersolute

Left Beaker:• More sugar molecules on the ____ side (low water

concentration).• • The membrane is permeable to water but not sugar.•

Section 7-3

Figure 7-15 Osmosis

1. How Osmosis Works

left

High water concentration on the right side.

Net movement of water from high water concentration to low water concentration.

Hypertonic Solution Isotonic Solution Hypotonic Solution

“above strength” “same strength” “below strength”

High concentration of Equal concentration of Low concentration of Dissolved substances dissolved substances dissolved substancesIn Solution in solution

TYPES OF SOLUTIONS

Cells in a hypertonic solutionCells in a hypertonic solution

In a hypertonic In a hypertonic solution, water solution, water leaves a cell by leaves a cell by osmosis, causing osmosis, causing the cell to shrink.the cell to shrink.

H2OH2O

Water MoleculeDissolved Molecule

Cells in a hypotonic solutionCells in a hypotonic solution In a hypotonic In a hypotonic

solution, water solution, water enters a cell by enters a cell by osmosis, causing osmosis, causing the cell to swell.the cell to swell.

H2OH2O

Water MoleculeDissolved Molecule

Cells in an isotonic solutionCells in an isotonic solution In an In an isotonic isotonic

solutionsolution, the , the concentration of concentration of dissolved substances dissolved substances in the solution is the in the solution is the same as the same as the concentration of concentration of dissolved substances dissolved substances inside the cell.inside the cell.

H2OH2O

Water MoleculeDissolved Molecule

2. The effects of Osmosis on cells (animal cells refer to figure 7-16)

Cells in a hypotonic solution

Cells in a hypertonic solution

Cells in an isotonicsolution

E. Facilitated Diffusion• Molecules, that cannot diffuse across the cell

membrane’s lipid bilayer on their own, can move

• Molecules still ___________________ concentration

HighConcentration

LowConcentration

CellMembrane

Glucosemolecules

Proteinchannel

Section 7-3

Facilitated Diffusion

With the help of protein channels

move from high to low

F. Active Transport• Movement of molecules

• Requires • Needs

Molecule tobe carried

Moleculebeing carried

Energy

against a concentration gradient (from low to high)

energy

a transport protein or pump

Large molecules and clumps of material can be taken into the cell by a process known as ___________. The two kinds of endocytosis are:

1. Phagocytosis=

2. Pinocytosis=

___________= release of large amounts of material

endocytosis

‘Cell eating’

‘cell drinking’

Exocytosis

endo/exocytosis demonstration

Transport of Large Transport of Large ParticlesParticlesTransport of Large Transport of Large ParticlesParticles

• Endocytosis is a process by which a cell surrounds and takes in material from its environment.

Endocytosis Exocytosis

Digestion

Nucleus

Wastes removal

Let’s Review:

PASSIVE TRANSPORTACTIVE

TRANSPORT

1. 2.

* *

*

Simple diffusion (includes Osmosis)

Facilitated Diffusion

No ATP No ATP ATP required

Hi-Lo Hi-Lo Lo-Hi

No protein Needs protein Needs Protein

1. interactive sites for cell membrane, diffusion, active, passive transport

Warm-upWarm-upSection 7-3Section 7-3

1.1. Describe the anatomy of a cell Describe the anatomy of a cell membrane.membrane.

2.2. What are the main functions of the What are the main functions of the cell membrane and the cell wall?cell membrane and the cell wall?

3.3. What happens during diffusion?What happens during diffusion?

4.4. What is osmosis?What is osmosis?

5.5. Describe the terms hypotonic, Describe the terms hypotonic, hypertonic, isotonic.hypertonic, isotonic.

6.6. Compare and contrast passive and Compare and contrast passive and active transport.active transport.

7-4 The Diversity of Cellular Life

A. Unicellular Organisms (single celled)• Unicellular organisms _________ multicellular

organisms

• Examples:

B. Multicellular Organisms (many celled)• Cells become ___________ to perform different

tasks

• Cells need to communicate and cooperate

outnumber

Yeast, algae, bacteria

specialized

C. Levels of Organization The levels of organization in a multicellular organism

are:

individual

Muscle cell

Smooth muscle( tissue)

Stomach(organ)

Digestive system(organ system)

SectionCELLS TISSUES ORGANS ORGAN

SYSTEMS

1. Tissues=• Four types of tissue:

-

-

-

-

2. Organs=

• Ex. bicep muscle is mad of muscle, connective, and nervous tissue

3. Organ Systems=

Group of similar cells that perform a particular function

muscle

epithelialnervous

connective

Groups of tissues

Group of organs that work together to perform a specific function.

Warm-upWarm-upSection 7-4Section 7-4

1.1. What are the levels of What are the levels of organization in a multicellular organization in a multicellular organism?organism?

2.2. What is cell specialization? What is cell specialization? Provide 3 examples.Provide 3 examples.