LE 7-2

Hydrophilichead

Hydrophobictail

WATER

WATER

LE 7-3

Hydrophilic regionof protein

Hydrophobic region of protein

Phospholipidbilayer

LE 7-5b

ViscousFluid

Unsaturated hydrocarbontails with kinks

Membrane fluidity

Saturated hydro-carbon tails

LE 7-5c

Cholesterol

Cholesterol within the animal cell membrane

LE 7-8

EXTRACELLULARSIDEN-terminus

C-terminusCYTOPLASMICSIDE

Helix

LE 7-15a

EXTRACELLULARFLUID

Channel protein Solute

CYTOPLASM

LE 7-17a

Diffusion Facilitated diffusion

Passive transport

LE 7-17b

ATP

Active transport

LE 7-17

Diffusion Facilitated diffusion

Passive transport

ATP

Active transport

LE 6-9a

Flagellum

Centrosome

CYTOSKELETON

Microfilaments

Intermediate filaments

Microtubules

Peroxisome

Microvilli

ENDOPLASMIC RETICULUM (ER

Rough ER Smooth ER

MitochondrionLysosome

Golgi apparatus

Ribosomes:

Plasma membrane

Nuclear envelope

NUCLEUS

In animal cells but not plant cells: LysosomesCentriolesFlagella (in some plant sperm)

Nucleolus

Chromatin

LE 6-9b

Roughendoplasmicreticulum

In plant cells but not animal cells: ChloroplastsCentral vacuole and tonoplastCell wallPlasmodesmata

Smoothendoplasmicreticulum

Ribosomes(small brown dots)

Central vacuole

Microfilaments

IntermediatefilamentsMicrotubules

CYTOSKELETON

Chloroplast

Plasmodesmata

Wall of adjacent cell

Cell wall

Nuclearenvelope

Nucleolus

Chromatin

NUCLEUS

Centrosome

Golgiapparatus

Mitochondrion

Peroxisome

Plasmamembrane

LE 6-10

Close-up of nuclearenvelope

Nucleus

Nucleolus

Chromatin

Nuclear envelope:Inner membraneOuter membrane

Nuclear pore

Porecomplex

Ribosome

Pore complexes (TEM) Nuclear lamina (TEM)

1 µm

Rough ER

Nucleus

1 µm

0.25 µm

Surface of nuclear envelope

LE 6-12

Ribosomes

Smooth ER

Rough ER

ER lumen

Cisternae

Transport vesicle

Smooth ER Rough ER

Transitional ER

200 nm

Nuclearenvelope

LE 6-2

Measurements1 centimeter (cm) = 10–2 meter (m) = 0.4 inch1 millimeter (mm) = 10–3 m1 micrometer (µm) = 10–3 mm = 10–6 m1 nanometer (nm) = 10–3 µm = 10–9 m

10 m

1 mHuman height

Length of somenerve andmuscle cells

Chicken egg

0.1 m

1 cm

Frog egg1 mm

100 µm

Most plant andanimal cells

10 µmNucleus

1 µm

Most bacteria

Mitochondrion

Smallest bacteria

Viruses100 nm

10 nmRibosomes

Proteins

Lipids

1 nmSmall molecules

Atoms0.1 nmU

na

ide

d e

ye

Lig

ht

mic

rosc

op

e

Ele

ctr

on

mic

ros

co

pe

LE 6-3a

Brightfield (unstained specimen)

50 µmBrightfield (stained specimen)

Phase-contrast

LE 6-6

A typicalrod-shapedbacterium

A thin section through thebacterium Bacilluscoagulans (TEM)

0.5 µm

Pili

Nucleoid

Ribosomes

Plasmamembrane

Cell wall

Capsule

Flagella

Bacterialchromosome

LE 6-7

Total surface area(height x width xnumber of sides xnumber of boxes)

6

125 125

150 750

1

11

5

1.2 66

Total volume(height x width x lengthX number of boxes)

Surface-to-volumeratio(surface area volume)

Surface area increases whileTotal volume remains constant

LE 6-11

Ribosomes

0.5 µm

ER Cytosol

Endoplasmicreticulum (ER)

Free ribosomes

Bound ribosomes

Largesubunit

Smallsubunit

Diagram ofa ribosome

TEM showing ERand ribosomes

LE 6-14a

Phagocytosis: lysosome digesting food

1 µm

Plasmamembrane

Food vacuole

Lysosome

Nucleus

Digestiveenzymes

Digestion

Lysosome

Lysosome containsactive hydrolyticenzymes

Food vacuolefuses withlysosome

Hydrolyticenzymes digestfood particles

LE 6-14b

Autophagy: lysosome breaking down damaged organelle

1 µm

Vesicle containingdamaged mitochondrion

Mitochondrionfragment

Lysosome containingtwo damaged organelles

Digestion

Lysosome

Lysosome fuses withvesicle containingdamaged organelle

Peroxisomefragment

Hydrolytic enzymesdigest organellecomponents

LE 6-15

5 µm

Central vacuole

Cytosol

Tonoplast

Central vacuole

Nucleus

Cell wall

Chloroplast

LE 6-16-1

Nuclear envelope

Nucleus

Rough ER

Smooth ER

LE 6-16-3

Nuclear envelope

Nucleus

Rough ER

Smooth ER

Transport vesicle

cis Golgi

trans Golgi

Plasma membrane

LE 6-17

Mitochondrion

Intermembrane space

Outer membrane

Inner membrane

Cristae

Matrix

100 nmMitochondrialDNA

Freeribosomes in themitochondrialmatrix

LE 6-18

Chloroplast

ChloroplastDNA

RibosomesStroma

Inner and outermembranes

Granum

Thylakoid1 µm