Human Bio Notes

8/9/2019 Human Bio Notes

1/17


2/17


3/17

Carrier Mediated Transport

• Molecules ind to proteins in the cell memrane to e transported across the

memrane,

• Carrier proteins are specific – the" *ill onl" ind to certain molecules

• Carrier proteins can ecome saturated – the" can onl" ind to a certain numer

of proteins &saturation point)

• Transport is regulated " hormones

• T*o t"pes$ .acilitated +iffusion and Acti(e Transport

/ facilitated diffusion is a passi(e process, It is the mo(ement of molecules

from a high concentration to a lo* concentration " inding to a carrier

protein, The molecule attaches to the inding site on the protein1 the carrier

changes shape and releases the molecule on the other side of the memrane,

/ acti(e diffusion is the transport of molecules from a lo* concentration to a

high concentration, It is an acti(e process and uses AT! molecules, Molecules

tra(el across the memrane similar to those in facilitated diffusion1 onl" going

against the concentration gradient,

Vesicular Transport

• The mo(ement of sustances across the cell memrane is memranous ags

called (esicles, Is an acti(e process,

• Endoc"tosis$ #ringing sustances into the cell, The cell memrane folds

around a droplet of li5uid or a solid particle until the droplet or particle is

completel" enclosed, The (esicle then pinches off and enters the c"toplasm,

/ !inoc"tosis$ Cell drining

/ !hagoc"tosis$ Cell eating

• E'oc"tosis$ %ustances e'iting the cell, Vesicle containing sustances

migrates to the cell memrane and fuses *ith the memrane, The (esicle then

opens and the contents are pushed out,

TY!E 4. TRA6%!4RT !A%%IVE7ACTIVE %U#%TA6CE%

+I..U%I46 !assi(e 8ater1 421 C421 alcohol1 fatt"

acids1 steroids1 ions &6a1 91 Ca)1

lipid solule drugs, 4smosis !assi(e 8ater

CARRIER ME+IATE+ :::::::: :::::::::::::,

.acilitated +iffusion !assi(e -lucose Amino Acids

Acti(e Transport Acti(e Certain ions &glucose1 AA;s)VE%ICULAR TRA6%!4RT :::::::: :::::::::::::,

Endoc"tosis Acti(e Cholesterol1 iron ions1 micro/

organisms and cell deris ut

onl" " certain speciali


4/17

• #ind *ith certain molecules outside the cell and trigger a response7reaction

*ithin the cell

• %pecific – each t"pe of receptor *ill ind *ith one t"pe of molecule &loc and

e" analog")

• +ifferent cells ha(e different t"pes and numers of receptor proteins therefore

there is a (ariation in the sensiti(ities of cells to hormones and other

sustances

• Receptor proteins also help in the communication *ith other cells

+6A

• A +6A molecule is made up of thousands of nucleotides

• Each nucleotide consists of riose &a >/caron sugar)1 a phosphate group and a

nitrogenous ase

• The t*o chains of alternating sugars and phosphates are no*n as the sugar/

phosphate acone

• The ases &once =oined) can e seen as the rungs on a ladder

• The t*o strands t*isted together are no*n as a doule heli'

• A chromosome contains appro'imatel" ?@ million ase pairs

.unctions of !roteins

• %tructure$ %trengthening hair1 nails1 sin &eratin) and strengthening and

maing one1 cartilage1 deep sin la"ers fle'ile &collagen)

• Transport across memranes$ carriers and channels,

• Communication$ 0ormones1 receptors

• Cell metaolism$ en


5/17

• tR6A$ a small R6A molecule that carries an AA to the riosome and places it

in the correct position determined " its corresponding mR6A

• -ene$ part of a +6A molecule that contains all the triplets needed to produce a

specific protein

• +6A$ a molecule in the nucleus of a cell that determines the t"pes of protein

that a cell can mae, 0olds the genetic information

• Chromosome$ rod/lie structures in the cells nucleus that carr" the hereditar"

information

• Triplet$ a section of +6A B ases long

• Codon$ a section of mR6A B ases long1 codes for a particular AA

!rotein %"nthesis

• Translation

The mR6A strand undergoes modification efore it lea(es the nucleus, The introns

&non/coding sections) are remo(ed from the strand1 lea(ing onl" the e'ons &coding

sections),

• Translation

Translation is the production of the protein that is coded in the mR6A strand, The

mR6A tra(els into the c"toplasm and a riosome attaches to one end of the strand

&*here the inding site of ases are – ensures riosome attaches to correct end of

mR6A),


6/17


7/17

%ummar" of !rotein %"nthesis$

Transcription$

/ T*o strands of the +6A in a gene separate – coding and templatestrand

/ mR6A forms complementar" to the ases on the template strand

/ modification$ introns are remo(ed to lea(e onl" e'ons

/ mR6A tra(els to the c"toplasm

Translation$

/ mR6A attaches to riosome

/ riosome mo(es along strand reading codons until it reached AU-

&start codon) *hen it *ill egin coding the mR6A and maing the

protein

/ for each codon1 a tR6A molecule *ith matching anticodon rings the

correct AA/ AA;s are onded together to form peptide chain &? AT! molecule per

ond) *hich is the protein

!rotein %tructure

!rimar" &?D) %tructure$ A chain of AA;s =oined "

peptide onds, The se5uence of AA;s that mae up

the protein, A protein ma" ha(e ? or more

AA;s in the chain and changing =ust one of these can

significantl" change the proteins properties and in

turn1 the function of the od",

%econdar" &2D) %tructure$ Is either a coiled or folded

shape, Is made " onds et*een different parts of

the AA chain, .orms sheets or spirals,

Tertiar" &BD) %tructure$ Is formed " further ending

and folding of the protein into gloular or firous

shapes,

uaternar" &@D) %hape$ &%ome proteins) Is formed*hen t*o or more AA chains interact7=oin,


8/17

Modif"ing and !acaging of !roteins

• AA chain goes to the -olgi Apparatus &or -olgi #od") *here %U-AR%1

!04%!0ATE%1 sulfates1 fatt" acids and other molecules &depending on the

desired protein) are added to create a functional protein

/ +6A holds info to mae proteins1 *hich mae en


9/17

• Is the determination of the precise order of the nucleotides in a sample of

+6A

• The method most commonl" used to determine this se5uence *as in(ented "

.RE+ERIC9 %A6-ER

• 4ur nucleotides &+eo'"nucleotide Triphosphates) are onded together (ia

their h"dro'"l groups

• The se5uence that has een shortened is then more easil" compared to the

+6A se5uences in 5uestion

• It is also a lot easier *oring *ith smaller1 more manageale sections of +6A

+6A %e5uencing !rocess

• The +6A is separated into t*o strand &" heating)

• The strand to e se5uenced is copied using s"ntheticall" altered ases

&thousands and thousands of copies)

• These altered ases cause the

cop"ing process to stop each

time one particular letter &e,g,

- – guanine) is incorporated

into the gro*ing +6A chain

• The location of that particular

ase can then e located on

the strand of +6A

• This process is carried out for all four ases1 and the

fragments are put together lie

a =igsa* to re(eal the

se5uence of the original piece

of +6A,

• #" comparing +6A se5uences1 changed alleles and mutations can e

identified and *ill sho* *hether an indi(idual has a particular disease,

Electrophoresis

4040

4040

0

00

0

8ithout the 0"dro'"l group1 the nucleotides

can;t ond together,

Therefore1 artificiall" made nucleotides1

ha(e another 0"drogen *here the 0"dro'"l

group should e,

This means that this artificial nucleotide

can;t =oin to another nucleotide1 hence

stopping the +6A molecule from gro*ing

and lengthening,


10/17

• +6% strands can e chopped up into smaller fragments using special en


11/17

• These B steps are repeated as necessar" &efore final step)

• .inal Elongation$ &J – J@DC)

/ after the last !CR c"cle

/ this ensures an" remaining strands are elongated

runs for ?> minutes

• .inal hold$ &@ – ?>DC)

/ allo*s for stoppage and storage of the reaction

Recominant +6A Technologies &aa -enetic Engineering)

• In(ol(es the

introduction of +6A

from one organism

into the +6A of

another organism,

• 0as the huge potential

of replacing fault"

genes *ith health"

ones

• Can help patients

suffering from c"stic

firosis1 rheumatoid

arthritis and certain

cancers

• Transgenic organisms

are those *hose


12/17

genome has een altered " the transfer of a gene or genes from another

organism

• These transferred genes ecome part of the organisms +6A and therefore can

e passed on to the ne't generation

• Recognition site$ a point *here there is a specific se5uence of ases *here

restriction en


13/17

• This process is used e'tensi(el" to detect +uchene muscular d"stroph" and

Thalasseamia

• If the gene in 5uestion is normal7health" the genetic proe *ill ind to the

+6A and the gene *ill e highlighted, If the gene is anormal1 the genetic

proe *ont e ale to ind to the +6A and nothing *ill e highlighted

• Man" techni5ues are used to detect the presence of a mutant gene3

/ +6A se5uencing

/ !rofiling techni5ues

/ !ol"merase Chain Reaction &!CR)

/ -enetic !roes

/ -enetic Engineering &recominant +6A technologies)

Chapter ?@ – I60ERITA6CE

• -ene$ Coding sections1 for the factors that determine hereditar" diseases1 on

the chromosomes• Allele$ Alternati(e forms of the same gene

• Chromosome$ Rod/shaped structures that carr" the hereditar" information

• Loci7lucus$ The location of a gene7 genes on a chromosome

• -ene Linage$ Certain characteristics tend to e inherited as a set

Multiple Alleles

• %till one gene1 ho*e(er there are more than 2 alleles and more than 2

phenot"pes

• E,g, #lood T"pes

A#4 #lood T"ping

• A;s1 #;s and 47s code for antigens that are present on the cell memrane ofR#C;s

• Antigen A K IA Antigen A # K IAI#

• Antigen # K I# 6o Antigen K i

• IA and I# are co/dominant – lending of characteristics

• i is recessi(e

Monogenic Inheritance

• There are man" alleles ut the pattern of inheritance is one *ith discrete

characteristics

• Each person has onl" one pair of alleles for the characteristics &e,g lood t"pe)

!ol"genic Inheritance• The inheritance of the characteristic is dependent on man" genes1 not =ust one

pair

• The en(ironment ma" also influence the e'pression of these characteristics

&e,g, diet1 e'ercise1 UV radiation1 disease causing organisms)

• 0air colour1 *eight1 height and sin colour


14/17


15/17

• -ene !ool$ the collection of genot"pes of all the indi(iduals that are capale

of reproduction &not infants) in a particular population

• Allele .re5uencies$ the occurrence of alleles of a gene in a population studied

• %pecies$ a group of indi(iduals that share man" characteristics and are ale to

interreed under natural conditions to produce fertile offspring

• There are @ *a"s to change the allele fre5uencies in a population$

/ Mutations

/ 6atural %election

/ Random -enetic +rift

/ #arriers to -ene .lo*

Mutations

• Random1 non/inherited (ariations appearing *ith no precursor and purel" "

chance

• Mutant$ an organism *ith a mutation

• -ene mutation$ change in a single gene so the traits normall" produced " that

gene are changes or destro"ed• Chromosomal mutation$ all or part of a chromosome is destro"ed

• %omatic mutations$ mutations occurring in somatic &od") cells that are not

passed on to the ne't generation

• -ermline Mutations$ mutations that occur in the reproducti(e &germinal) cells

that are passed on to the ne't generation

6atural %election

• Charles +ar*in$ .ather of E(olution, A naturalist *ho proposed and pro(ed

*ith scientific e(idence that all species of life ha(e e(ol(ed o(er time from

common ancestors through the process of natural selection

• .orms the asis of the modern e(olutionar" theor"• Can e (ie*ed as the selection of genes in a population that gi(e an organism

a greater chance of sur(i(al, The organisms that sur(i(e can pass on their

genetic information &*ith these fa(ourale characteristics) and graduall" o(er

a long period of time1 the population *ill ecome etter suited to the

en(ironment

• 6atural selection CA664T occur in a changing en(ironment

• There are B oser(ations that for the theor" of 6atural %election$

/ Variation$ All memers of a species (ar" and these (ariations are passed on

from generation to generation

/ #irth rate$ all li(ing things increase their numers at a rate greater than theira(ailale resources allo* &food1 shelter1 *ater etc)

/ 6atures #alance$ although the irth rate of organisms *as (er" high1 the

species tended to maintain their numers at a relati(el" constant le(el


16/17


17/17

• %ocio/cultural arriers$ +e(eloped as human cultures ecame more comple',

Religion1 economic status1 education1 social position &main @) and language

&to some e'tent),

• -ene .lo*$ The transfer of genetic information from one population to

another, If isolation has een e'treme and o(er an e'tended period of time1 itma" not e possile for populations to interreed if the" come together again

• %peciation$ The formation of ne* species, .or a ne* species to form &e,g,

et*een t*o separated populations)1 there needs to e (ariation *ithin oth

populations1 isolation of the t*o populations1 en(ironmental pressures

&*eather1 UV1 diet1 chemicals) and it needs to occur o(er an e'tended period

of time,

• .ounders Effect$ %imilar to -enetic +rift &e'cept change is more immediate),

8hen a small population mo(es a*a" from the original population and

estalishes a ne* communit", This ne* communit" is not geneticall"

representati(e of the homeland population and usuall" sho*s non/t"pical &forthe original population) characteristics,

E,g, the ount" mutineer descendents &*ith nati(e Tahitian men and *omen)

Documents

Human Bio Notes