Searching for Scale - Office of Science Education (OSE)€¦ · Searching for Scale Name: Date: Master 1.1 Biological Structure Actual Diameter (in Meters) Size Relative to Cell Object

Searching for Scale

Name: Date:

Master 1.1

Biological Structure

ActualDiameter

(in Meters)

Size Relative to Cell Object Used to Model Biologi-cal structure

Measured Size of

Model Object

Size Relative to Model Cell (the Room)

Cell 1 × 10–5 1 × 10–5

1 × 10–5Room 10 meters 10

10

Bacterium 1 × 10–6 1 × 10–6

1 × 10–5Desk 1 meter

Mitochondrion 5 × 10–7 5 × 10–7

1 × 10–5

Virus 1 × 10–7

Ribosome 1 × 10–8

Protein 5 × 10–9

Glucose molecule

1 × 10–9

H2O molecule 1 × 10–10

= 1

= 110

= 120

= 1

= 110

110

Master 2.1

Probing for Answers Score Sheet

A B C D E F G H I

1

2

3

4

5

6

7

8

9

Master 2.2

Probes

Master 2.3

Probing for Answers—Level 1

A B C D E F G H I

1

2

3

4

5

6

7

8

9

Level 1

Master 2.4


A B C D E F G H I

1

2

3

4

5

6

7

8

9

Level 2

Master 2.5


A B C D E F G H I

1

2

3

4

5

6

7

8

9

Level 3

Master 2.6


A B C D E F G H I

1

2

3

4

5

6

7

8

9

Level 4

Master 2.7


A B C D E F G H I

1

2

3

4

5

6

7

8

9

Level 5

Master 2.8


A B C D E F G H I

1

2

3

4

5

6

7

8

9

Level 6

Master 2.9

Solution to Probing for Answers

Master 3.1

Memo from the Director, Global Science and Health Organization

MemoTO: Members, Scientific and Health Evaluation Teams

FROM: Director, Global Science and Health Organization

RE: New disease

Our Division of Disease Surveillance recently reported a new disease affecting approximately 30% of the persons living in a small rural area of the United States. Affected individuals have a lack of energy and demonstrate a progressive loss of muscle function. Although we have no information yet, we believe the disease is caused by an infectious agent. Consequently, to limit the spread of this disease, immediate intervention is critical.

We need your expertise to answer these questions: 1. Is there evidence of disease at the cellular level? If so, 2. Is the disease caused by an infectious agent? If it is, 3. What is the infectious agent? 4. Does the infectious agent attack muscle tissue? 5. How might the infectious agent cause the disease? 6. Is there a drug to treat or prevent the disease?

Blood and muscle tissue samples from unaffected and affected individuals are waiting for you. The microscopy and X-ray crystallography facilities at GSHO are being readied for your arrival. In order to gain information as quickly as possible, please develop a solid research plan before beginning your investigations.

Good luck!

Global Science and Health Organization

Master 3.2

Research PlanName: Date:

1. To answer the question,

2. I will use this technology:

3. I chose this technology because

4. My hypothesis is

5. I expect one of the following two results:

6. Observations (actual results) and interpretation:

Master 3.3

Example of a Research Plan1. To answer the question,



4. My hypothesis is

5. I expect one of the following two results:





4. My hypothesis is (continue as above).





4. My hypothesis is (continue as above).

Is there evidence of disease at the cellular level (in

muscle cells)?

Light Microscope

its resolution level allows me to see muscle cells.

There is evidence of disease in muscle cells.

I will see abnormal muscle cells in affected

individuals OR I will see NO abnormal muscle cells in affected individuals.

Result 1—Muscle cells from affected individuals are different from normal muscle cells and those from unaffected individuals; interpreted as evidence of disease in muscle of affected individuals. Proceed to next question.

Is the disease caused by an infectious agent (bacteria)?

Light Microscope

its resolution level allows me to see bacteria.

Result 2—Muscle cells from affected individuals appear the same as normal muscle cells and muscle cells from unaffected individuals. Interpreted as lack of evidence of disease in muscle cells of affected individuals. Look for evidence of disease in other tissues.

Is there evidence of disease at the cellular level (blood)?

Light Microscope

its resolution level allows me to see blood cells.

OR

Master 3.4

Drug Discovery Evaluation Form

Name: Date:

Molecule 1: Evaluation of X-ray crystallography, protein structure data:




Overall evaluation: Is there a drug you would recommend to treat the disease? Justify your response.

Ava

ilab

le T

ech

nol

ogie

s

Mas

ter

3.5

Scie

nce

Ref

eren

ce M

anu

al

Mas

ter

3.6(

a)

Scie

nce

Ref

eren

ce M

anu

alT

able

of

Con

ten

ts

Ligh

t M

icro

scop

y

Th

e fi

rst

mic

rosc

opes

wer

e op

tica

l on

es,

wh

ich

use

gla

ss le

nse

s to

foc

us

and

mag

nif

y li

ght.

Alt

hou

gh H

ans

and

Sach

aria

s Ja

nss

en

con

stru

cted

th

e fi

rst

opti

cal m

icro

scop

e in

159

5,

it w

as n

ot u

nti

l 60

to 8

0 ye

ars

late

r th

at m

ajor

di

scov

erie

s w

ere

mad

e w

ith

th

is t

ech

nol

ogy.

In

th

e la

te 1

600s

, An

ton

io v

an L

eeu

wen

hoe

k im

prov

ed t

he

len

ses

use

d in

mic

rosc

opes

, al

low

ing

mag

nif

icat

ion

to

be in

crea

sed

from

50x

to

200

x. T

her

e w

ere

addi

ton

al im

prov

emen

ts

to o

ptic

al m

icro

scop

y ov

er t

he

nex

t 30

0 ye

ars,

w

hic

h u

ltim

atel

y in

crea

sed

mag

ific

atio

n u

p to

1,5

00x

and

allo

wed

opt

ical

mic

rosc

opes

to

reso

lve

obje

cts

as s

mal

l as

200

nan

omet

ers

(nm

;2

x 10

–7 m

). T

his

res

olu

tion

is a

ph

ysic

al li

mit

di

ctat

ed b

y th

e w

avel

engt

h o

f li

ght

(th

at is

, its

si

ze a

s a

prob

e).

Tran

smis

sion

EM

Sect

ion

1: T

ech

nol

ogy

L

igh

t M

icro

scop

y

Ele

ctro

n M

icro

scop

y

X-R

ay C

ryst

allo

grap

hy

Sect

ion

2: I

nfe

ctio

us

Dis

ease

Cau

sati

ve A

gen

ts

Infe

ctio

us

Dis

ease

Bac

teri

a

Vir

use

s

Sect

ion

3: B

lood

Sect

ion

4: M

usc

le

Mu

scle

Str

uct

ure

M

usc

le P

rote

ins

M

usc

le C

ontr

acti

on

Sect

ion

5: D

rug

Dis

cove

ry

Rat

ion

al B

asis

for

New

D

rug

Dev

elop

men

t

Elec

tron

Mic

rosc

opy

Th

e fi

rst

elec

tron

mic

rosc

ope

(EM

) w

as b

uil

t in

19

33 b

y E

rnst

Ru

ska

(198

6 N

obel

Pri

ze w

inn

er

for

ach

ieve

men

ts in

ele

ctro

n o

ptic

s). R

usk

a u

sed

acce

lera

ted

elec

tron

s an

d m

agn

etic

coi

ls t

o m

ake

an im

age

inst

ead

of li

ght

and

glas

s le

nse

s.

Ele

ctro

ns

hav

e a

wav

elen

gth

(si

ze)

that

is 1

04 to

105 t

imes

sm

alle

r th

an t

he

wav

elen

gth

of

ligh

t. E

Ms

can

res

olve

obj

ects

th

at a

re 1

03 tim

es

smal

ler

than

th

e sm

alle

st r

esol

vabl

e ob

ject

in a

li

ght

mic

rosc

ope.

Tran

smis

sion

EM

s yi

eld

info

rmat

ion

sim

ilar

to

tra

nsm

issi

on li

ght

mic

rosc

opes

abo

ut

the

size

, sh

ape,

an

d ar

ran

gem

ent

of p

arti

cles

in a

sp

ecim

en, a

lth

ough

at

mu

ch h

igh

er r

esol

uti

on.

Th

e h

igh

-res

olu

tion

tra

nsm

issi

on E

M c

an

mag

nif

y a

sam

ple

up

to 5

0,00

0 x a

nd

prov

ide

a re

solu

tion

of

0.1

nm

(0.

1 x

10–9

m).

Hig

h-R

esol

utio

nTr

ansm

issi

on E

M

Th

e re

solu

tion

of

EM

s ca

n b

e im

prov

ed t

hro

ugh

mod

ific

atio

ns

of

the

sam

ple

prep

arat

ion

pro

cedu

re. I

n

cryo

-EM

, spe

cim

ens

are

froz

en r

apid

ly

to e

lim

inat

e ic

e cr

ysta

ls f

rom

for

min

g th

at c

an d

isto

rt t

he

spec

imen

’s st

ruct

ure

. Sam

ples

are

th

en v

iew

ed a

t te

mpe

ratu

res

as lo

w a

s –1

85ºC

.

Two-

an

d th

ree-

dim

ensi

onal

mod

els

of

the

sam

ple

can

be

reco

nst

ruct

ed u

sin

g a

com

pute

r pr

ogra

m t

hat

ave

rage

s m

any

elec

tron

mic

rogr

aph

s ta

ken

fr

om d

iffe

ren

t an

gles

.C

ryo-

EM

Scie

nce

Ref

eren

ce M

anu

al

Mas

ter

3.6(

b)

X-R

ay C

ryst

allo

grap

hy

X-r

ays,

wit

h w

avel

engt

hs a

ppro

xim

atel

y th

e sa

me

size

as

the

spac

ing

betw

een

atom

s, a

re d

irec

ted

thro

ugh

a cr

ysta

l of t

he s

ubst

ance

und

er s

tudy

. The

X-r

ays

are

bent

by

the

elec

tron

s su

rrou

ndin

g th

e at

oms

in t

he c

ryst

al. T

he s

catt

ered

X-r

ays

prod

uce

a pa

tter

n as

the

y ex

it t

he c

ryst

al. L

ocat

ions

at

whi

ch X

-ray

s ar

e re

ceiv

ed

by a

det

ecto

r ar

e re

cord

ed a

s da

rk s

pots

on

a fi

lm. S

ophi

stic

ated

com

pute

r pr

ogra

ms

use

mea

sure

men

ts o

f the

ang

les

of t

he s

catt

ered

X-r

ays

and

thei

r in

tens

itie

s to

cal

cula

te t

he t

hree

-dim

ensi

onal

pos

itio

ns o

f the

ato

ms

in t

he c

ryst

al.

By r

otat

ing

the

crys

tal a

nd m

akin

g m

any

two-

dim

ensi

onal

imag

es, i

t is

pos

sibl

e to

co

mbi

ne r

esul

ts t

o pr

oduc

e a

thre

e-di

men

sion

al p

ictu

re o

f the

mol

ecul

e.

Ele

ctro

n m

icro

scop

y re

quir

es a

sam

ple

thin

en

ough

to

allo

w e

lect

ron

s to

pas

s th

rou

gh. S

ampl

es s

mal

ler

than

1/5

00th

th

e di

amet

er o

f a

hu

man

hai

r ar

e u

sed.

In

a t

ran

smis

sion

EM

, ele

ctro

ns

pass

th

rou

gh t

he

sam

ple

and

are

imag

ed o

n

a fl

uor

esce

nt

scre

en a

t th

e bo

ttom

of

the

mic

rosc

ope

colu

mn

. Sam

ples

th

at

are

mor

e el

ectr

on d

ense

all

ow f

ewer

ele

ctro

ns

to p

ass

thro

ugh

. Th

is r

esu

lts

in

a da

rker

im

age.

In

som

e ca

ses,

ch

emic

als

that

are

ele

ctro

n d

ense

an

d bi

nd

to

spec

ific

cel

lula

r co

mpo

nen

ts a

re u

sed

as s

tain

s. T

hes

e st

ain

s m

ake

it p

ossi

ble

to

view

cel

l co

mpo

nen

ts t

hat

th

emse

lves

are

not

ele

ctro

n d

ense

.

Thi

s is

a t

ypic

al d

iffr

acti

on

patt

ern

prod

uced

by

pass

ing

X-r

ays

thro

ugh

a pr

otei

n cr

ysta

l. T

he d

ark

spot

s re

p-re

sent

int

ensi

ties

of

X-r

ays

and

plac

es w

here

X-r

ays

have

str

uck

the

dete

ctor

. Sc

ient

ists

mea

sure

the

loc

a-ti

on a

nd i

nten

sity

of

the

scat

tere

d X

-ray

s. T

he w

hite

ci

rcle

to

the

righ

t of

cen

ter

wit

h th

e w

hite

lin

e ex

tend

-in

g to

the

lef

t is

a s

hado

w

from

a “

beam

stop

.” T

he

beam

stop

is

a sm

all

piec

e of

lea

d m

ount

ed o

n a

met

al

arm

. It

prot

ects

the

det

ecto

r fr

om t

he i

nten

se b

eam

of

unsc

atte

red

X-r

ays.

Soph

isti

cate

d co

mpu

ter

prog

ram

s co

nver

t th

e da

ta f

rom

X-r

ay c

ryst

allo

grap

hy

patt

erns

int

o th

ree-

dim

ensi

onal

mod

els

of p

rote

ins,

suc

h as

the

one

abo

ve o

f M

utY,

a D

NA

-rep

air

prot

ein.

Scie

nce

Ref

eren

ce M

anu

al

Mas

ter

3.6(

c)

Bac

teri

a

Bact

eria

are

sin

gle-

celle

d pr

okar

yoti

c or

gani

sms.

Mos

t ba

cter

ia a

re fr

om 0

.3 t

o 2.

0 x

10–6

m in

dia

met

er. M

ost

are

harm

less

, and

man

y pe

rfor

m h

elpf

ul

func

tion

s. O

nly

a sm

all n

umbe

r of

bac

teri

a ar

e pa

thog

ens.

Cho

lera

, lep

rosy

, pn

eum

onia

, tub

ercu

losi

s, a

nd w

hoop

ing

coug

h ar

e ex

ampl

es o

f hum

an d

isea

ses

caus

ed b

y ba

cter

ia t

hat

dest

roy

heal

thy

cells

. Dip

hthe

ria,

sca

rlet

feve

r, te

tanu

s,

and

botu

lism

are

hum

an d

isea

ses

caus

ed b

y to

xins

tha

t ba

cter

ia p

rodu

ce.

Bact

eria

are

div

ided

into

gro

ups

acco

rdin

g to

sha

pe, a

s se

en b

elow

. Som

e ba

cter

ia

may

be

foun

d in

sm

all g

roup

s or

clu

ster

s.

Vir

use

s at

tach

to

prot

ein

s ca

lled

rec

epto

rs o

n t

he

surf

ace

of c

ells

. Th

is a

llow

s th

e vi

rus

or i

ts n

ucl

eic

acid

to

ente

r th

e ce

ll. P

rote

ins

enco

ded

by t

he

viru

s’s n

ucl

eic

acid

can

th

en b

e pr

odu

ced

by t

he

cell

. Th

ese

prot

ein

s m

ay a

ffec

t ce

ll f

un

ctio

ns

by b

indi

ng

to c

ell

prot

ein

s, a

lter

ing

met

abol

ism

, or

som

e ot

her

mea

ns.

Th

ey a

lso

may

be

use

d to

man

ufa

ctu

re n

ew v

iru

s pa

rtic

les.

Infe

ctio

us

Dis

ease

Infe

ctio

us d

isea

ses

resu

lt w

hen

an o

rgan

ism

or

othe

r ag

ent

ente

rs t

he b

ody

and

repr

oduc

es it

self

. Inf

ecti

ous

agen

ts, o

r pa

thog

ens,

can

pro

duce

dis

ease

in s

ever

al

way

s. F

or in

stan

ce, p

atho

gens

can

pro

duce

che

mic

al a

gent

s, s

uch

as p

rote

ins

or

othe

r sm

all m

olec

ules

, whi

ch c

an d

amag

e ti

ssue

. Als

o, t

he c

hem

ical

age

nts

can

inte

rfer

e w

ith

norm

al c

ellu

lar

proc

esse

s or

act

as

toxi

ns.

The

mos

t co

mm

on p

atho

gens

are

bac

teri

a an

d vi

ruse

s. O

ther

pat

hoge

ns in

clud

e fu

ngi,

wor

ms,

and

pro

tozo

ans.

Vir

use

sV

irus

es a

re s

mal

l par

ticl

es c

onsi

stin

g of

a c

ore

of n

ucle

ic a

cid

and

an o

uter

coa

t of

prot

ein.

The

y liv

e w

ithi

n ce

lls o

f liv

ing

orga

nism

s. V

irus

es g

ener

a lly

are

rod

s or

sp

here

s th

at r

ange

in s

ize

from

abo

ut 0

.1 to

3 x

10–7

m. T

he w

ord

viru

s is

der

ived

from

a

Lati

n w

ord

mea

ning

poi

son.

Thi

s is

app

ropr

iate

sin

ce v

irus

es a

re a

maj

or c

ause

of

dise

ase,

eve

n th

ough

som

e vi

ruse

s ar

e ha

rmle

ss. D

isea

ses

in h

uman

s th

at v

irus

es c

ause

in

clud

e A

IDS,

chi

cken

pox,

col

ds, i

nflu

enza

, col

d so

res,

mea

sles

. mum

ps, a

nd r

abie

s.

The

pro

tein

coa

t of a

vir

us g

ives

the

part

icle

its

char

acte

rist

ic s

hape

, as

illus

trat

ed in

th

e fo

llow

ing

exam

ples

:

Ebo

la v

irus

from

EM

Rab

ies

viru

sfr

om E

MH

uman

her

pes

viru

sfr

om E

M

Hum

an in

flue

nza

viru

s fr

om E

MH

uman

pap

illo

ma

viru

s fr

om E

MH

uman

pol

io v

irus

fr

om c

ryo-

EM

re

cons

truc

tion

Coc

cus

Bac

illu

sSp

iroc

hete

Vib

rio

Master

Scie

nce

Ref

eren

ce M

anu

al

Mas

ter

3.6(

d)

Blo

od

App

roxi

mat

ely

55 p

erce

nt o

f blo

od is

a s

traw

-col

ored

cle

ar li

quid

cal

led

plas

ma.

T

he r

emai

nder

of b

lood

is c

ompo

sed

of v

ario

us c

ell t

ypes

, as

seen

abo

ve.

Red

blo

od c

ells

are

dis

c-sh

aped

and

con

tain

hem

oglo

bin,

a p

rote

in t

o w

hich

ox

ygen

bin

ds. N

eutr

ophi

ls a

nd ly

mph

ocyt

es a

re t

he m

ajor

whi

te b

lood

cel

ls.

The

se p

rovi

de t

he b

ody’

s m

ajor

def

ense

aga

inst

infe

ctio

n. P

late

lets

are

sm

all c

ells

in

volv

ed in

blo

od c

lott

ing.

Eac

h m

yofi

bril

is

mad

e of

tw

o ki

nds

of

para

llel

fil

a-m

ents

. Thi

ck f

ilam

ents

are

1.

6 x

10–6

m l

ong

and

mad

e of

myo

sin

. Thi

n fi

lam

ents

ar

e 1

x 10

–6 m

lon

g an

d m

ade

of a

ctin

. Th

in f

ila-

men

ts e

xten

d in

bot

h d

irec

-ti

ons

from

a p

rote

in t

hat

fo

rms

a re

gion

cal

led

the

z li

ne.

Th

e ar

ea b

etw

een

tw

o z

lin

es i

s a

sarc

omer

e. T

his

is

the

fun

ctio

nal

un

it o

f sk

el-

etal

mu

scle

. Sar

com

eres

are

th

e sm

alle

st u

nit

s th

at c

an

perf

orm

all

of

the

fun

ctio

ns

of m

usc

le t

issu

e.

Blo

od s

mea

r vi

ewed

at

400x

wit

h a

ligh

t m

icro

scop

e.

Tran

smis

sion

EM

of

lym

phoc

yte

and

red

bloo

d ce

ll (

RB

C)

(2,0

00x)

.

Mu

scle

Str

uct

ure

Skel

etal

mus

cle,

als

o kn

own

as s

tria

ted

mus

cle,

is m

ade

of m

any

mus

cle

fibe

rs, e

ach

of w

hich

ext

ends

the

leng

th o

f the

mus

cle

(up

to 2

.5 fe

et lo

ng).

M

uscl

e fi

bers

are

arr

ange

d pa

ralle

l to

one

anot

her,

and

a m

embr

ane

calle

d th

e sa

rcol

emm

a bu

ndle

s th

em t

oget

her.

Eac

h fi

ber

cont

ains

mul

tipl

e nu

clei

and

nu

mer

ous

mit

ocho

ndri

a, b

ecau

se e

ach

mus

cle

fibe

r de

velo

ps fr

om t

he fu

sion

of

man

y ce

lls c

alle

d m

yofi

brils

tha

t ex

tend

the

leng

th o

f the

fibe

r.

Lig

ht m

icro

grap

h of

a lo

ngit

udin

al

sect

ion

of n

orm

al s

kele

tal m

uscl

e;

dark

ova

l str

uctu

res

are

nucl

ei.

Lig

ht m

icro

grap

h sh

owin

g st

riat

ed

appe

aran

ce o

f no

rmal

mus

cle

fibe

r.

Ele

ctro

n m

icro

grap

h of

hum

an s

kele

tal m

uscl

e.

Master

Scie

nce

Ref

eren

ce M

anu

al

Mas

ter

3.6(

e)

Mu

scle

Pro

tein

s

Mus

cle

fibe

rs a

re m

ade

up o

f man

y di

ffer

ent

prot

eins

arr

ange

d in

a

spec

ific

way

. The

ir a

rran

gem

ent

and

indi

vidu

al p

rope

rtie

s al

low

m

uscl

e to

func

tion

. Som

e pr

otei

ns s

erve

str

uctu

ral r

oles

, whi

le o

ther

s ar

e di

rect

ly in

volv

ed in

mus

cle

cont

ract

ion

and

rela

xati

on.

Up

to o

ne-f

ifth

of t

he p

rote

in in

mus

cle

cells

is a

ctin

, whi

ch fo

rms

the

thin

fila

men

ts o

f the

cel

ls.

Abo

ut 3

60 a

ctin

mol

ecul

es c

ombi

ne t

o fo

rm a

long

cha

in. T

wo

of

thes

e ch

ains

are

tw

iste

d in

to a

dou

ble

helix

to

form

an

acti

n fi

lam

ent.

Sp

ecia

lized

pro

tein

s st

abili

ze t

he fi

lam

ent.

Myo

sin

mak

es u

p ab

out

45 t

o 50

per

cen

t of

m

usc

le c

ontr

acti

le p

rote

ins

and

is t

he

maj

or

prot

ein

of

the

thin

k fi

lam

ents

.

Myo

sin

use

s ch

emic

al e

ner

gy t

o pe

rfor

m

mot

ion

. Th

e m

yosi

n m

olec

ule

loo

ks s

ome-

wh

at l

ike

two

golf

clu

bs w

ith

th

eir

shaf

ts

wra

pped

aro

un

d ea

ch o

ther

.

Seve

ral

oth

er p

rote

ins

hel

p m

ain

tain

th

e st

ruct

ure

of

the

thic

k fi

lam

ents

.

Cry

o-E

M r

econ

stru

ctio

n of

an

act

in d

oubl

e he

lix.

Mu

scle

Con

trac

tion

At

the

tip

of t

he m

yosi

n m

olec

ule

is a

cle

ft t

hat

bind

s to

the

act

in fi

lam

ent.

The

le

ver

arm

of t

he m

yosi

n pu

shes

the

myo

sin

mol

ecul

e al

ong

the

acti

n fi

lam

ent.

M

uscl

e co

ntra

ctio

n re

quir

es a

ctin

, myo

sin,

and

oth

er p

rote

ins,

the

impo

r tan

t m

iner

al c

alci

um, a

nd e

nerg

y in

the

form

of a

deno

sine

tri

phos

phat

e (A

TP)

.

Cry

o-E

M r

econ

stru

ctio

n of

a m

yosi

n m

olec

ule

(lef

t) a

nd a

thi

ck m

yosi

n fi

lam

ent

in b

etw

een

two

thin

act

in f

ilam

ents

(ri

ght)

.

Rat

ion

al B

asis

for

New

Dru

g D

evel

opm

ent

The

key

to

rati

onal

dru

g de

sign

is u

nder

stan

ding

the

str

uctu

re a

nd fu

ncti

on o

f bi

olog

ical

mol

ecul

es in

volv

ed in

dis

ease

dev

elop

men

t. T

o de

velo

p dr

ugs

that

figh

t di

seas

e, s

cien

tist

s se

arch

for

chem

ical

and

bio

logi

cal s

ubst

ance

s th

at t

arge

t ce

llula

r an

d m

olec

ular

fact

ors

that

pla

y a

role

in d

isea

se. M

any

tool

s ar

e us

ed in

rat

iona

l dr

ug d

esig

n, in

clud

ing

mic

rosc

opic

tec

hniq

ues,

X-r

ay t

echn

ique

s, c

ompu

ter

anal

yses

, and

sim

ulat

ions

.

The

aim

of r

atio

nal d

rug

desi

gn is

to

prod

uce

drug

s w

ith

grea

ter

sele

ctiv

ity

and,

the

refo

re,

grea

ter

effe

ctiv

enes

s. T

he a

ppro

ach

diff

ers

from

th

e tr

adit

iona

l med

icin

al a

ppro

ach,

whi

ch r

elie

s on

mor

e ex

tens

ive

and

rand

om t

esti

ng.

MasterMaster 3.7

Muscle Protein Structures Determined by X-Ray Crystallography

Muscle protein from affected people

Along z-axis Along x-axis Along y-axis

Muscle protein from unaffected people

Along z-axis Along x-axis Along y-axis

MasterMaster 4.1

Microscopes Across Time

1754 Culpepper microscope

1850 Ross microscope

1909 Leitz Wetzler microscope

1948 Spencer microscope

2004 Modern research microscope

MasterMaster 4.2

Some Key Developments in Biology, Medicine, and Technology, by Year

BIOLOGY1665 Cells first described (Robert Hooke).1839 Proposal made that animal tissues are composed of cells (Theodor Schwann).1869 DNA discovered (Friedrich Miescher).1911 Structure of the atom discovered (Ernest Rutherford).1942 Myosin and actin reported to be the main structural proteins of muscle (Albert Szent-

Gyorgi and colleagues).1953 Double helix model of DNA proposed (James Watson and Francis Crick; their model was

supported by X-ray crystallography done by Maurice Wilkins and Rosalind Franklin).1953 Structure of hemoglobin determined using X-ray crystallography (Max Perutz and John

Kendrew).2000 Atomic structure of the large subunit of a bacterial ribosome resolved using X-ray crys-

tallography (Thomas Steitz and colleagues).

MEDICINE1862 Germ theory published: infection is caused by bacteria (Louis Pasteur).1868 First diagnosis made of a complex disease, multiple sclerosis (Jean Martin Charcot).1892 Viruses discovered (Dimitri Ivanovsky).1892 White blood cells identified (Elie Metchnikoff).1893 First modern American medical school opens (Johns Hopkins University, Baltimore, Md.).1895 First pharmaceutical research laboratory founded (Parke-Davis Company, Detroit, Mich.).1928 Penicillin discovered (Alexander Fleming).1959 First major drug to treat leukemia invented (Gertrude Elion).

TECHNOLOGY1593 Thermometer invented (Galileo).1883 First induction motor constructed, the basis of generating electricity (Nicola Tesla).1895 X-rays discovered (Wilhelm Conrad Roentgen).1912 X-ray crystallography invented (William Bragg).1923 First electric refrigerator produced (Electrolux, Old Greenwich, Conn.).1927 First working model of television (Philo Farnsworth).1932 Electron microscope invented (Max Knoll and Ernst Ruska).1969 First microprocessor designed, the basis for computer development (Marcian Hoff).

Searching for Scale - Office of Science Education (OSE)€¦ · Searching for Scale Name: Date: Master 1.1 Biological Structure Actual Diameter (in Meters) Size Relative to Cell Object

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