biology i lect 4 cell function.ppt

7/18/2019 Biology I Lect 4 Cell Function.ppt

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1

Biology I Lecture 4

Cell Structure and Function



2

Points to ponder

• What is a cell?• Why are most cells small?

• What do prokaryotic and eukaryotic cells have in

common?• How are cells organized?

• How do things move across the plasma

membrane?

• What is cellular respiration?



3

What does the cell theory tell us?

• A cell is the basic unit of life.

• All living things are made up of cells.

• ew cells arise from pre!e"isting cells.

#.$ What is a %ell?



4

Why are most cells small?

• %onsider the cell surface!area!to!volume

ratio.

& 'mall cells have a larger amount of surface

area compared to the volume.

& An increase in surface area allows for more

nutrients to pass into the cell and wastes to

e"it the cell more efficiently. & (here is a limit to how large a cell can be) and

be an efficient and metabolically active cell.

#.$ What is a %ell?



5

(hinking about surface

area!to!volume in a cell

#.$ What is a %ell?

Figure 3.2 'urface area!to!volume ratio limits cell size.

%opyright * (he +c,raw!Hill %ompanies) -nc. Permission reuired for reproduction or display.

Total surface area

(height × width × nu!er of sides × nu!er of cu!es"

Total #olue

(height × width × length × nu!er of cu!es"

$urface area%

&olue 'er cu!e (surface area#olue"

)%13%11.5%1

)4 c3

3*4 c31+2 c3+) c3

)4 c3 )4 c3

,ne

4-c cu!e

ight

2-c cu!es

$i/ty-four

1-c cu!es



)

What are some common

microscopes used to view cells?• %ompound light microscope

& /ower magnification

& 0ses light beams to view images

& %an view live specimens

#.$ What is a %ell?




microscopes used to view cells?• (ransmission electron microscope

& 1!2 image

& 0ses electrons to view internal structure

& High magnification) no live specimens

#.$ What is a %ell?


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microscopes used to view cells?• 'canning electron microscope

& #!2 image

& 0ses electrons to view surface structures

& High magnification) no live specimens

#.$ What is a %ell?


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3lood cells viewed with different

microscopes

#.$ What is a %ell?

Figure 3.3 +icrographs of human red blood cells.


a. Light icrogra'h !. Transission electron icrogra'h c. $canning electron icrogra'h

!lood #essel wall

red !lood cells

red !lood cell red !lood cell

!lood #essel wall !lood #essel wall

a4 * 2avid +. Phillips56isuals 0nlimited7 b 4 * Alfred Pasieka5 Photo 8esearchers7

c4 * 19$#5Warren 8osenberg5 3iological Photo 'ervice



What are the 1 ma:or types of

cells in all living organisms?• Prokaryotic cells

& (hought to be the first cells to evolve

& /ack a nucleus

& 8epresented by bacteria and archaea

• ;ukaryotic cells & Have a nucleus that houses 2A

& +any membrane!bound organelles

#.1 How %ells are <rganized



What do prokaryotic and

eukaryotic cells have in common?• A plasma membrane that surrounds and

delineates the cell

• A cytoplasm4 the semi!fluid substance inside the

cell that contains organelles

• 2A

#.1 How %ells are <rganized



What do eukaryotic cells look like?#.1 How %ells are <rganized

Figure 3.4 (he

structure of a

typicaleukaryotic cell.


a. 2.5

lasa e!rane%outer surface that

regulates entrance and

e/it of olecules

'rotein

'hos'holi'id

T,$6LT,7% aintainscell sha'e and assists o#eent

of cell 'arts%

8icrotu!ules% cylinders of 'rotein olecules 'resentin cyto'las9 centrioles9

cilia9 and flagella

Interediate filaents%'rotein fi!ers that

'ro#ide su''ortand strength

:ctin filaents% 'roteinfi!ers that 'lay a role in

o#eent of cell

and organelles

entioles% short9cylinders of icrotu!ules

&esicle% e!rane-!oundedsac that stores and trans'orts

su!stances

!.

yto'las% seifluidatri/ outside nucleus

that contains organelles

entrosoe% icrotu!ulesorgani;ing center thatcontains a 'air of centroles

Lysosoe% #esicle that

digests acroolecules

and e#en cell 'arts

<olgi a''aratus% 'rocesses9 'ac=ages9

and secretes odified cell 'roducts

olyri!osoe% string of ri!osoes siultaneouslysynthesi;ing sae 'rotein

8itochondrion% organellethat carries out cellular res'iration9 'roducing

:T olecules

>i!osoes%'articles that carry

out 'rotein synthesis

$ooth >% lac=sri!osoes9 synthesi;es

li'id olecules

>ough >% studded withri!osoes9 'rocesses 'roteins

7?,L:$8I >TI@L@8%

7ucleolus% region that 'roduces

su!units of ri!osoes

hroatin% diffuse threadscontaining ?7: and 'rotein

7uclear en#elo'e% dou!lee!rane with nuclear 'ores

that encloses nucleus

7@L@$%

itochondrion

chroatin

nucleolus

nuclear

en#elo'e

endo'lasicreticulu

* 2ennis =unkel56isuals 0nlimited



Where did eukaryotic cells come from?#.1 How %ells are <rganized

Figure 3.5 (he evolution ofeukaryotic cells.


?7:

1. ell gains a nucleus !y the

'lasa e!rane in#aginating and surrounding the ?7:

with a dou!le e!rane.

7ucleus allows s'ecific functionsto !e assigned9 freeing u' cellular

resources for other wor=.

2. ell gains an endoe!rane syste !y 'roliferation

of e!rane.

Increased surface area allows

higher rate of trans'ort of aterials within a cell.

3. ell gains itochondria.

:!ility to eta!oli;e sugars in

the 'resence of o/ygen ena!lesgreater function and success.

4. ell gains chloro'lasts.

:!ility to 'roduce

sugars fro sunlightena!les greater

function and success.

chloro'last

lant cell

has !oth itochondriacnd chloro'lasts.

:nial cellhas itochondria9!ut not chloro'lasts.

itochondrion

aero!ic!acteriu

'hotosynthetic!acteriu

,riginal'ro=aryotic cell



What are some characteristics

of the plasma membrane?• -t is a phospholipid bilayer.

• -t is embedded with proteins that move in space.

• -t contains cholesterol for support.

• -t contains carbohydrates on proteins and lipids.

• -t is selectively permeable.

#.# (he Plasma +embrane and How 'ubstances %ross -t


http://slidepdf.com/reader/full/biology-i-lect-4-cell-functionppt 15/4815Figure 3.) <rganization of the plasma membrane.



,utside

hydro'hilic

heads

car!ohydrate

chain

glyco'rotein

cholesterol

integral 'rotein

filaents of cytos=eleton

'hos'holi'id

!ilayer

hydro'ho!ic

tails

Inside

'eri'heral 'rotein

'lasa e!rane

e/tracellular

atri/ (8"

glycoli'id

# # (h Pl + b d H ' b % -


http://slidepdf.com/reader/full/biology-i-lect-4-cell-functionppt 16/481)

What does selectively permeable

mean?• (he membrane

allows somethings in whilekeeping other

substances out.


A

'hos'holi'id

olecule

'rotein

acroolecule

aCua'orin noncharged

olecules

D2,

charged olecules

and ions A


Figure 3.0 'elective permeability of theplasma membrane.

# # (h Pl + b d H ' b t % -t



How do things move across the

plasma membrane?

$. 2iffusion

1. <smosis#. >acilitated transport

. Active transport

@. ;ndocytosis and e"ocytosis


# # (he Plasma +embrane and How 'ubstances %ross -t


http://slidepdf.com/reader/full/biology-i-lect-4-cell-functionppt 18/481*

What are diffusion and osmosis?

$. 2iffusion is the random movement of molecules from

a higher concentration to a lower concentration.

1. <smosis is the diffusion of water molecules.




http://slidepdf.com/reader/full/biology-i-lect-4-cell-functionppt 19/481+


Figure 3.* 2iffusion across the plasma membrane.

What are diffusion and osmosis?%opyright * (he +c,raw!Hill %ompanies) -nc. Permission reuired for reproduction or display.

'article

'lasa

e!rane water

cell cell

tie

a. Initial conditions !. Cuili!riu conditions

# # (h Pl + b d H ' b t % -t



How does tonicity change a cell?

• -sotonic solutionshave eual amountsof solute inside andoutside the cell andthus do not affect thecell.


Figure 3.+a ;ffects of changes in tonicity on red blood cells.


a. Isotonic solution

(sae solute concen-

tration as in cell"* 2ennis =unkel5Phototake





• Hypotonic solutionshave less solute thanthe inside of the celland lead to lysisburstingB.


Figure 3.+! ;ffects of changes in tonicity on red blood cells.

!. Dy'otonic solution

(lower solute concen-

tration than in cell"

D2,


* 2ennis =unkel5Phototake





• Hypertonic solutionshave more solutethan the insideof the cell and lead tocrenation shrivelingB.


Figure 3.+c ;ffects of changes in tonicity on red blood cells.

c. Dy'ertonic solution

(higher solute concen-

tration than in cell"

D2,


* 2ennis =unkel5Phototake




23

What are facilitated diffusion andactive transport?

#. >acilitated transport is the transport ofmolecules across theplasma membranefrom higherconcentration tolower concentrationvia a protein carrier.


6A

7 a A

7 a A

Inside

,utside

glucose


Figure 3.1 >acilitated transport across a cell membrane.




24

What are facilitated diffusion and

active transport?. Active transport is the

movement of moleculesfrom a lower to higher

concentration using A(Pas energy7 it reuires aprotein carrier.


7 a A

Inside

,utside

7 a A

6A

6A

6A

7 a A

6A6A

7 a A

7aA

7 a

A

7 a A

:T

:?


Figure 3.11 Active transport and the sodium&potassium pump.




25

What are endocytosis

and e"ocytosis?• @. ;ndocytosis transports

molecules or cells into the cell

via invagination of the plasma

membrane to form a vesicle.

• C. ;"ocytosis transports

molecules outside the cell viathe fusion of a vesicle with the

plasma membrane.


'lasa e!rane

#acuole

a. hagocytosis

solute

#esicle

!. inocytosis

rece'tor 'rotein

coated #esiclecoated 'it

solute

c. >ece'tor-ediated endocytosis


Figure 3.12 +ovement of large molecules across the membrane.

# (he ucleus and ;ndomembrane 'ystem



2)

What structures are involved in

protein production?• ucleus

• 8ibosomes

• ;ndomembrane system

#. (he ucleus and ;ndomembrane 'ystem




20

What is the structure and

function of the nucleus?

• 3ound by a porous nuclear envelope

•

• Houses chromatin4 2A with associatedproteins

• ucleolus contains ribosomal 8A r8AB





2*

What is the structure and

function of ribosomes?

• <rganelles made of r8A and protein

• >ound bound to the endoplasmic reticulumand free floating in the cytoplasm

• 'ites of protein synthesis





2+Figure 3.13 (he nucleus and endoplasmic reticulum.



nuclear

'ores

sooth >

nuclear

en#elo'e

chroatin

nucleolus

rough >

nuclear poresB4 %ourtesy ;.,. Pollock7 ;8B4 * 8. 3olender D 2. >awcett56isuals 0nlimited




3

What is the endomembrane

system?• -t is a series of membranes in which molecules

are transported in the cell.

• -t consists of the nuclear envelope) endoplasmic

reticulum) ,olgi apparatus) lysosomes) and

vesicles.





31

How does the endomembrane system function?secretion

'lasa

e!rane

incoing #esicle

en;ye

lysosoe

contains digesti#e en;yes

that !rea= down cell 'arts or

su!stances entering !y #esicles

trans'ort #esicle

ta=es li'ids to

<olgi a''aratus

li'id

sooth endo'lasic

reticulu

synthesi;es li'ids and has

#arious other functions

rough endo'lasic

reticulu

synthesi;es 'roteins and

'ac=ages the in #esicles

trans'ort #esicle

ta=es 'roteins to

<olgi a''aratus

'rotein

<olgi a''aratus

odifies li'ids and 'roteins

fro the >E sorts and 'ac=ages

the in #esicles

secretory #esicle

7ucleus

ri!osoe


Figure 3.14 (he endomembrane system.





32

How can we summarize the parts

of the endomembrane system?• 8ough endoplasmic reticulum & studded with

ribosomes used to make proteins

• 'mooth endoplasmic reticulum & lacks ribosomesbut aids in making carbohydrates and lipids

• ,olgi apparatus & flattened stacks that process)package) and deliver proteins and lipids from the;8





33

How can we summarize the parts

of the endomembrane system?• /ysosomes & membranous vesicles made by the

,olgi that contain digestive enzymes

• 6esicles & small membranous sacs used fortransport


#.@ (he %ytoskeleton) %ell +ovement) and %ell Eunctions



34

What is the cytoskeleton?

• A series of proteins that maintain cell shape) as

well as anchors and5or moves organelles in the

cell

• +ade of # types of fibers4 large microtubules)

thin actin filaments) and medium!sized

intermediate filaments





35

Flagellu

icrotu!ules

'lasae!rane

cilia

s'er

flagellu

secretory cell

flagellu

!.

c.

a.


bB4 * F. ikas5Photo 8esearchers) -nc.7 cB4 * 2avid +. Phillips5Photo 8esearchers) -nc.

• 3oth are made of

microtubules.

• 3oth are used inmovement.

• %ilia are about 19×

shorter than flagella.

What are cilia and flagella?

Figure 3.15 'tructure and function of the cilia

and flagella.

y ) )




3)

What are cell :unctions?

• Eunctions between thecells of human tissue

that allow them to

function in a

coordinated manner• # main types

& Adhesion :unctions

mechanically attach

ad:acent cellscommon in skin

cellsB.

y ) )

Figure 3.1)a Eunctions between cells.


filaents of

cytos=eleton

'lasae!ranes

a. :dhesion unction

intercellular

s'ace

intercellular

filaents




30


& (ight :unctions are

connections between

the plasma membrane

proteins of

neighboring cells thatproduce a zipper!like

barrier common in

digestive system and

kidney where fluids

must be contained to

a specific areaB.

y ) )

Figure 3.1)! Eunctions between cells.

'lasa

e!ranes

tight unction

'roteins

intercellular

s'ace

!. Tight unction





3*


& ,ap :unctions are

communication

portals between

cells7 channel

proteins of theplasma membrane

fuse) allowing easy

movement between

ad:acent cells.

y ) )

Figure 3.1)c Eunctions between cells.

'lasa

e!ranes

e!ranechannels

intercellular

s'ace

c. <a' unction


#.C +itochondria and %ellular +etabolism



3+

What do mitochondria do and what do

they look like?

• Highly folded

organelles in

eukaryotic cells

• Produce energy in the

form of A(P

• (hought to be derived

from an engulfed

prokaryotic cell


2 natri/

intere!rane

s'ace

outer

e!raneinner

e!rane

cristae

topB 4 * 2r. 2on W. >awcett56isuals 0nlimitedFigure 3.10 (he structure of a mitochondrion.




4

;nzymes are important for cellular

respiration and many activities in the cell• +ost enzymes are proteins.• ;nzymes are often named for the molecules that

they work on) called substrates.• ;nzymes are specific to what substrate they workon.

• ;nzymes have active sites where a substrate binds.• ;nzymes are not used up in a reaction but instead

are recycled.• 'ome enzymes are aided by nonprotein molecules

called coenzymes.




41

How do enzymes work?


acti#e site

en;ye

su!strate

'roducts

en;ye

en;yesu!strate

co'le/

$ynthesis

$u!strates are co!ined

to 'roduce a larger 'roduct.

?egradation

: su!strate is !ro=en

down to saller 'roducts.

'roduct

en;ye

en;yesu!strate

co'le/

en;ye

acti#e site

su!strates

Figure 3.1* Action of an enzyme.




42

What is cellular respiration?

• Production of A(P in a cell

• -ncludes

$. ,lycolysis

1. %itric acid cycle =rebs cycleB

#. ;lectron transport chain




43Figure 3.1+ Production of A(P.


,utside cell

2 322

Inside cell

electrons

transferred

!y 7:?D

:T:T:T

itochondrion

lectron

trans'ortchain

itric

acidcycle

o/ygen

glucose

electrons

transferred!y 7:?D

glucose

<lycolysis

'yru#ate

#.C +itochondria and cellular metabolism



44

,lycolysis

& <ccurs in the cytoplasm

& 3reaks glucose into 1 pyruvate

& A2H and 1 A(P molecules are made

& 2oes not reuire o"ygen




45

%itric acid cycle =rebs cycleB

& A cyclical pathway that occurs in the

mitochondria

& Produces A2H and 1 A(P

& 8eleases carbon dio"ide




4)

;lectron transport chain

• 'eries of molecules embedded in the

mitochondrial membrane

& A2H made in steps $ and 1 carry electrons

here & #1!# A(P are made depending on the cell

& 8euires o"ygen as the final electron

acceptor in the chain




40

What other molecules besides glucose

can be used in cellular respiration?• <ther carbohydrates

• Proteins

• /ipids




How can a cell make A(P without

o"ygen?

• >ermentation4

& occurs in the cytoplasm.

& does not reuire o"ygen. & involves glycolysis.

& makes 1 A(P and lactate in human cells.

& can give humans a burst of energy for a shorttime.

biology i lect 4 cell function.ppt

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