AP Biology 2013-2014

Tour of the Cell 1

http://www.dnatube.com/video/55

1/The-Inner-Life-Of-A-Cell-HQ

AP Biology

Cytology: science/study of cells

Electron microscopy – electron beam

TEM: to study cell internal ultrastructure

SEM: to study cell surfaces

To view cells: Light microscopy

resolving power: measure of clarity

http://www.vcbio.science.ru.nl/en/fes

em/info/cryosem/

AP Biology

SEM Cool

images

dog flea Foraminifera

(a protist)

Leaf part

Polysterene

aggregate

Pb(Zr, Ti)O3

Micro- & nano

organisms

hair

http://www.vcbio.science.r

u.nl/en/fesem/applets/flea/

Leaf (guard cells)

AP Biology

Cytology: science/study of cells

http://www.youtube.com/watch?v=8B

nES4T1RDk

To isolate organelles:

Cell fractionation: to separate major organelles

Ultracentrifuge: cell fractionation;

130,000rpm or 1,000,000 g

AP Biology

NUCLEI

MITOCHONDRIA

MEMBRANES -

ROUGH

ENDOPLASMIC

RETICULUM

Centrifuge at LOW SPEED

for 10 minutes

Centrifuge at MODERATE

SPEED

for 15 minutes

Centrifuge at HIGH SPEED

for 30 minutes

Organelle Isolation: Cell Fractionation & Ultracentrifugation

AP Biology

Size is relative

http://www.cellsalive.com/howbig.htm

http://htwins.net/scale2/

AP Biology

Cell Size http://learn.genetics.utah.edu/content/begin/cells/scale/

AP Biology

Cell Radius 1 2 3 4

SA (r2) 1 4 9 16

V (r3) 1 8 27 64

SA = 4 r2

V = 4/3 r3

SA/V (r2/r3) 1 1/2 1/3 1/4

Cell Size

V > SA

r V and SA

r SA/V

AP Biology

Cell Size As cell size increases, the SA to V ratio

decreases

Rates of chemical exchange may then be

inadequate for cell size

Cell size, therefore, remains small

What happens when the cell reaches a

critical size?

AP Biology

Prokaryote

bacteria cells Types of cells

Eukaryote

animal cells

- no organelles

- organelles

Eukaryote

plant cells http://www.yellowtang.org/animations/cell_features_v2.swf

AP Biology

AP Biology

Cell Types: Prokaryotic

Nucleoid: DNA

concentration

No organelles with

membranes

Ribosomes:

protein synthesis

Plasma membrane:

(all cells); semi-permeable

Cytoplasm/cytosol (all cells)

Prokaryotes contain no

organelles.

Organelles are

membrane bound.

Ribosomes are not

membrane bound.

Ribosomes are not

organelles.

AP Biology

Cell types: Eukaryotic

Nucleus:membrane enclosed organelle

containing chromosomes

Membrane bound organelles of

specialized form and function

Generally larger than prokaryotic cells

AP Biology

Why organelles? Specialized structures

specialized functions

cilia or flagella for locomotion

Containers

partition cell into compartments

create different local environments

separate pH, or concentration of materials

distinct & incompatible functions

lysosome & its digestive enzymes

Membranes as sites for chemical reactions

unique combinations of lipids & proteins

embedded enzymes & reaction centers

chloroplasts & mitochondria

mitochondria

chloroplast

Golgi

ER http://www.cellsalive.com/cells/cell_model.htm

AP Biology

Cells must work to live! What jobs do cells have to do?

make proteins

proteins control every

cell function

make energy

for daily life

for growth

make more cells

growth

repair

renewal

AP Biology 2013-2014

Building Proteins

http://www.johnkyrk.com/aminoacid.ht

ml

http://sciencenetlinks.com/interactives/

protein.html

http://www.phschool.com/

atschool/phsciexp/active_

art/protein_synthesis/inde

x.html

http://www.rcsb.org/pd

b/101/static101.do?p=

education_discussion/

educational_resources/

index.html#Posters-

Exhibits

AP Biology

Proteins do all the work!

cells

DNA

proteins

organism Repeat after me…

Proteins do all the work!

AP Biology

Cells functions http://vcell.ndsu.nodak.edu/animations/proteinmodification/

movie-flash.htm

Building proteins

read DNA instructions

build proteins

process proteins

folding

modifying

removing amino acids

adding other molecules

e.g, making glycoproteins

for cell membrane

address & transport proteins

AP Biology

Building Proteins Organelles involved

nucleus

ribosomes

endoplasmic reticulum (ER)

Golgi apparatus

vesicles

nucleus ribosome ER Golgi

apparatus vesicles

The Protein Assembly Line

AP Biology

nuclear pores

nuclear pore

nuclear envelope

nucleolus

histone protein

chromosome

DNA

Function

protects DNA

Structure

nuclear envelope

double membrane

membrane fused in spots to create pores

allows large macromolecules to pass through

Nucleus

What kind of molecules need to

pass through?

http://www.youtube.com/watch?

v=gbSIBhFwQ4s

http://www.biostudio.com/demo_fre

eman_dna_coiling.htm

AP Biology

DNA Wrapping

AP Biology

DNA Packaging

AP Biology

DNA

Nucleus mRNA

nuclear membrane

small ribosomal

subunit

large ribosomal

subunit

cytoplasm

mRNA

nuclear pore

production of mRNA

from DNA in nucleus

mRNA travels from

nucleus to ribosome

in cytoplasm through

nuclear pore

1

2

http://www.dnalc.org/resources/3d/12-transcription-basic.html

http://www.dnalc.org/view/15481-Translation-RNA-to-

protein-3D-animation-with-no-audio.html

http://www.youtube.com/watch?v=I9ArIJWYZHI

http://www.youtube.com/watch?v=4jtmOZa

IvS0&feature=related

http://www.dnalc.org/view/15889-RNA-

polymerase-game-interactive-2D-animation.html

Build RNA

AP Biology

What kind of molecules

pass through the pore?

AP Biology

Nucleolus

small subunit

large subunit

ribosome

rRNA & proteins

nucleolus

Function

ribosome production

build ribosome subunits from rRNA & proteins

exit through nuclear pores to cytoplasm &

combine to form functional ribosomes

AP Biology

Ribosomes

0.08mm

Ribosomes

Rough ER

Smooth ER

small subunit

large subunit

Function

protein production

Structure

rRNA & protein

2 subunits combine

AP Biology membrane proteins

Types of Ribosomes Free ribosomes

suspended in cytosol

synthesize proteins that

function in cytosol

Bound ribosomes

attached to endoplasmic

reticulum

synthesize proteins

for export or

for membranes

AP Biology

Endoplasmic Reticulum Function

processes proteins

manufactures membranes

synthesis & hydrolysis of many compounds

Structure

membrane connected to nuclear envelope &

extends throughout cell

AP Biology

Types of ER

rough smooth

AP Biology

Smooth ER function Membrane production

Many metabolic processes

synthesis

synthesize lipids oils, phospholipids, steroids & sex hormones

hydrolysis hydrolyze glycogen into glucose

in liver

detoxify drugs & poisons in liver ex. alcohol & barbiturates

AP Biology

Membrane Factory Build new

membrane

synthesize phospholipids builds membranes

ER membrane expands bud off & transfer

to other parts of cell that need membranes

AP Biology

Rough ER function Produce proteins for export out of cell

protein secreting cells

packaged into transport vesicles for export

Which cells have lot of rough ER?

AP Biology

Synthesizing proteins

cytoplasm

cisternal space

mRNA

ribosome

membrane of endoplasmic reticulum

polypeptide

signal sequence

ribosome

http://www.dnalc.org/view/15890-Ribosome-

game-interactive-2D-animation.html

Build a protein

http://www.dnalc.org/view/15481-Translation-

RNA-to-protein-3D-animation-with-no-audio.html

AP Biology

Golgi Apparatus

Which cells have lots of Golgi?

transport vesicles

secretory vesicles

Function

finishes, sorts, tags & ships cell products

like “UPS shipping department”

ships products in vesicles

membrane sacs

“UPS trucks”

http://www.sumanasinc.com/webcontent/animati

ons/content/vesiclebudding.html

AP Biology

Golgi Apparatus http://www.goldiesroom.org/Shockwave_P

ages/011--Golgi%20Complex.htm

AP Biology

Vesicle transport

vesicle budding from rough ER

fusion of vesicle with Golgi apparatus

migrating transport vesicle

protein

ribosome

http://highered.mcgraw-

hill.com/sites/0072495855/student_view0/chapte

r2/animation__lysosomes.html

http://www.goldiesroom.org/Shockwave_Pages/

011--Golgi%20Complex.htm

AP Biology

Vesicles

Regents Biology

DNA

RNA

ribosomes

endoplasmic

reticulum

vesicle

Golgi

apparatus

vesicle

protein on its way!

protein finished protein

Making Proteins

TO:

TO:

TO:

TO:

nucleus

You should be able to label each step.

AP Biology

proteins

transport vesicle

Golgi apparatus

vesicle

smooth ER

rough ER

nuclear pore nucleus

ribosome

cell membrane protein secreted

cytoplasm

Making proteins Putting it together…

Describe “making

proteins”?

AP Biology

Lysosomes Function

little “stomach” of the cell

digests macromolecules

“clean up crew” of the cell

cleans up broken down

organelles

Structure

vesicles of digestive

enzymes

only in

animal cells

synthesized by rER,

transferred to Golgi

Where old organelles go to die!

AP Biology

Lysosomes

white blood cells attack &

destroy invaders = digest

them in lysosomes

1974 Nobel prize: Christian de Duve

Lysosomes discovery in 1960s

1960 | 1974

AP Biology

Cellular digestion Lysosomes fuse with food vacuoles

polymers

digested into

monomers

pass to cytosol

to become

nutrients of

cell vacuole

lyso– = breaking things apart

–some = body

http://highered.mcgraw-

hill.com/sites/0072495855/student_view0/chapte

r2/animation__lysosomes.html

http://highered.mcgraw-

hill.com/olc/dl/120067/bio01.swf

AP Biology

Lysosomal enzymes Lysosomal enzymes work best at pH 5

organelle creates custom pH

how?

proteins in lysosomal membrane pump H+ ions from

the cytosol into lysosome

why?

enzymes are very sensitive to pH

why?

enzymes are proteins — pH affects structure

why evolve digestive enzymes which function at

pH different from cytosol?

digestive enzymes won’t function well if some leak into

cytosol = don’t want to digest yourself!

http://faculty.ccbcmd.edu/courses/bio141/lecguid

e/unit4/innate/acidification_phagosome.html

http://highered.mcgraw-

hill.com/olcweb/cgi/pluginpop.cgi?it=swf::5

35::535::/sites/dl/free/0072437316/120068

/bio05.swf::Proton%20Pump

AP Biology

When things go bad… Diseases of lysosomes are often fatal

digestive enzyme not working in lysosome

picks up biomolecules, but can’t digest one

lysosomes fill up with undigested material

grow larger & larger until disrupts cell &

organ function

lysosomal storage diseases

more than 40 known diseases

example:

Tay-Sachs disease

build up undigested fat

in brain cells (autosomal rec)

Mutation in:

hexosaminidase

A, (helps break

down

gangliosides)

AP Biology

Lysosomal storage diseases

Lipids

Gaucher’s disease

Niemann-Pick disease

Tay Sachs

Glycogen & other polysaccharides

Farber disease

Krabbe disease

Proteins

Schindler’s disease

http://www.youtube.com/wa

tch?v=WbUpMBHioT8

Niemann-Pick Disease

AP Biology

Lysosomal storage diseases Gaucher’s

-autosomal recessive disorder

-deficiency of glucocerebrosidase,

a lysosomal enzyme that catalyses

the hydrolysis of the glycolipid

glucocerebroside ceramide + glucose

AP Biology

Lysosomal storage disease

Hepatosplenomegaly courtesy of The

National MPS Society, Inc.

http://www.lysosomallearning.com/heal

thcare/about/lsd_hc_abt_niemann.asp

AP Biology

But sometimes cells need to die… Lysosomes can be used to kill cells when

they are supposed to be destroyed

some cells have to die for proper

development in an organism

apoptosis

“auto-destruct” process

lysosomes break open & kill cell

ex: tadpole tail gets re-absorbed

when it turns into a frog

ex: loss of webbing between your

fingers during fetal development

AP Biology

Fetal development

15 weeks

6 weeks

syndactyly

AP Biology

Apoptosis

programmed destruction of cells in multi-

cellular organisms

programmed development

control of cell growth

example:

if cell grows uncontrollably this self-destruct

mechanism is triggered to remove damaged cell

cancer must over-ride this to enable tumor

growth

AP Biology

AP Biology

AP Biology 2013-2014

Any Questions!!