A798057369_21039_13_2018_Structure & Organization-Animal cell-Dr. Mishra.pdf

A798057369_21039_13_2018_Structure & Organization-Animal celA798057369_21039_13_2018_Structure & Organization-Animal celA798057369_21039_13_2018_Structure & Organization-Animal celA798057369_21039_13_2018_Structure & Organization-Animal cell

1. Cells

Structure and Function
Jibanananda Mishra, MS, MPhil, PhD.
Associate Professor

2. Discovery of Cells

e The invention of the lens

e Robert Hooke (1665):
observed a thin slice of cork > is
(dead plant cells) with a ec
microscope. He described
what he observed as “little
boxes” (cells).

3. Discovery of Cells

e Anton van Leeuwenhoek
(1675): was the first person to

4. Microscopes

e Magnification: refers to the
microscope’ s power to increase
an object’ s apparent size

e Resolution: refers to the

microscope’ s power to show
detail clearly

KO (o

5. Resolving Power Line

What can you see with the different types of microscopes? The human eye is capable of
distinguishing objects down to a fraction of a millimeter. With the use of light and electron
microscopes it is possible to see down to an angstrom and study everything from different
cells and bacteria to single molecules or even atoms.

im idm 1cm imm 100 um 10 ym um 100nm 10nm 1nm 12 0,14

1074m_10"5m 106m 107m 108m 102m 1010m 10711m

im 1071 m 102m 103m

Light microscope*

Electron microscope”

ye

man hand finger thickness cell bacterium virus | macro small atom
height of hair mole- mole-
cule cule

scope includes

ase contrast and fluorescence microscopes. Electron micri

* Light microscope Includes
transmisson electron microscope.

6. 10x Wicefield,
Eyepiece

Course &
Fine Focusing

360 Rotating
H

Objective Lens
4x, 10x, 40x

Eye

Ce

Final Image —

Eyepiece

Projector
Lens

Objective

Specimen

~~ condenser Lens

7. 1croscope

ht M

Lig

- Elodea

Plant

1C

Aquati

8. Transmission Electron Microscope (TEM)

Electron
= source

9. Transmission Electron Microscope (TEM)

10. Scanning Electron Microscope (SEM)

11. EM

ron Micr

nning El

S

12. Scanning Electron Microscope (SEM)

13. Scanning Electron Microscope (SEM)

14. Scanning Electron Microscope (SEM)

Neuron

15. Scanning Electron Microscope (SEM)

Pollen

Cell, Platelet, |
and White |
Blood Cell |

16. TEM vs. SEM

Viruses
leaving a cell

17. Cell Theory

e Three Parts:
— 1) All organisms are made of cells
— 2) The cell is the most basic unit of life

— 3) Cells come from other cells

e What's the big problem with this theory?

18. Cell Theory

e Detailed study of the cell began in the
1830s

e A unifying concept in biology

e Originated from the work of biologists e
Schleiden and Schwann in 1838-39
4

States that:
All organisms are composed of cells
German botanist Matthais Schleiden in 1838
German zoologist Theodor Schwann in 1839
All cells come only from preexisting cells
German physician Rudolph Virchow in 1850’ s

Cells are the smallest structural and functional
unit of organisms

19. The Cell Theory

e Who developed the cell theory? 4

- Matthias Schleiden (1838): e +
concluded that all plants are TT
composed of cells

- Theodor Schwann (1839):
concluded that all animals are
composed of cells

- Rudolph Virchow (1855):

determined that cells come only
from other cells

20. The Cell Theory

e What is the cell theory?

_ All living things are composed of one
or more cells.

- Cells are organisms’ basic units of
structure and function.

- Cells come only from existing cells.

21. Cell Diversity

e Size
e Shape
e Internal Organization

22. 1 centimeter

à (cm) = R
1/100 meter, ue
| ‚or 0.4 inch i
L
| 1 millimeter
| (mm) = 1 mm frog egg, fish
1/1,000 meter ace =

1 micrometer
(am) =
1/1,000,000 meter

human egg

typical plant cells
typical animal cells
chloroplast
mitochondrion
Anabaena
(cyanobacterium)
Escherichia coli

1 nanometer
(am) =

1/1,000,000,000 meter

27

0.1

al

large virus (HIV,
influenza virus

ribosome

cell membrane
(thickness)

DNA double helix
(diameter)
hydrogen atom

1 meter = 102 cm = 10% mm = 108 um = 109 nm

23. BATERIA

Smallest Cells:

2» loam

Cell Diversity- Size

nn Biggest Cells:

Longest Cells: 6 inches long, 5 inches

GIRÄFFE
Netve
eek

TOTAL
LENGTH
UPTO lm

24. Surface Area to Volume Ratio

SA = 6 mm?
V=1mm?
SA/V =6:1 SA = 24 mm?
V=8 mm?
SA/V =3:1
V increases faster than SA SA = 96 mm?

| V = 64 mm°

SA/V = 1.5:1

25. Why cells are small
and organisms are
made up of cells!

SA:Vol ratio 6 4.2 6
(surface area + volume)

26. e Cells differ widely in shape.

e Most cells are roughly
cuboidal or spherical.

27. Cell Diversity- Internal Organization

e Nucleus: contains DNA which directs the activity
of the cell

e Organelle: a cell component that performs
specific functions in the cell

e Eukaryotes: cells that contain a nucleus and
membrane-bound organelles

e Prokaryotes: cells that lack nuclei and
membrane-bound organelles

28. Eukaryotes vs. Prokaryotes

e Eukaryotes (animals,
plants, fungi, protists)
and prokaryotes
(bacteria) differ greatly
in structure.

29. Cell Diversity

Shape depends upon function
Nerve Shape: Elongated branching
— Function: Sends messages to and from brain
Red Blood Shape: Disc-like shape prevents clogging
— Function: Carries O, throughout blood
e Skin Shape: Flat & broad; layers overlap
— Function: Covers and protects the body

30. Cell Categories

e 1) Prokaryote: Cells without a nucleus and other
membrane-bound organelles
— Oldest cells known (~4 billion years old)
— Believed to have evolved first (oldest fossils)
— Bacteria

31. Cell Categories

Middle Lamella
“Typical” Cell ‚Cell Wall

Chloroplast Cell Membrane
Nucleus

Mitochondrion

a Ribosome
Vesicle

Endoplasmic
Reticulum

Golgi_/
Apparatus

e 2) Eukaryote: Cells

with a nucleus &

membrane bound

organelles

— More complex cells

— Evolved from
prokaryotes

— Ex: Protists, Fungi,
Plants, Animals

32. Hypothesized Origin of Eukaryotic Cells

€
5) [4 Gel gains chloroplasts|
=

33. Eukaryotic Cells

e Domain Eukarya includes:
— Protists
— Fungi
— Plants
— Animals

e Cells contain:
— Membrane-bound nucleus that houses DNA
— Specialized organelles
— Plasma membrane
— Much larger than prokaryotic cells
Some cells (e.g., plant cells) have a cell wall

34. Structure and Function of Organelles

e The Structure and Function of the following
organelles will be discussed:

— Cell Membrane
— Nucleus
— Cell Wall
— Cytoplasm
— Cytoskeleton
— Ribosomes
— Endoplasmic Reticulum
— Golgi Apparatus

Mitochondria
Lysosomes
Peroxisomes
Cilia and Flagella
Basal Bodies
Centrioles
Vacuoles
Plastids

35. Structure and Function of Organelles

A cell is the basic, living, structural and functional
unit of the body.

Cell Theory:

The building blocks of all plants and animals
All cells come from the division of preexisting
cells

Cells are the smallest units that perform all vital
physiological functions

Each cell maintains homeostasis at the cellular
level.

36. Cell Size

e Cells are measured in micrometers.

e Cells vary in size and shape.

e Shape is determined by function.

e Two types of cells:
— Sex cells
— Somatic (body) cells

e Cells are surrounded by extracellular fluid,
which is called interstitial fluid in most
tissues

37. Cell Size

Red
blood cell
@

7.5um

White
blood cell

[ir
12 um

38. Cell Size

e Cells range in size from one millimeter down to
one micrometer
e Cells need a large surface area of plasma
membrane to adequately exchange materials.
e The surface-area-to-volume ratio requires that
cells be small
— Large cells - surface area relative to volume decreases

— Volume is living cytoplasm, which demands nutrients
and produces wastes

— Cells specialized in absorption utilize membrane
modifications such as microvilli to greatly increase
surface area per unit volume

39. Surface to Volume Ratio

One 4-cm cube Eight 2-cm cubes Sixty-four 1-cm cubes

(height x width x number of sides x number of cubes)
192 cm? 384 cm?

40. Cell Shape and Function

Cell Shape and Function

A

Muscle cell GL
(cantract/pull) ES

Epithelial cells
(protect)

Nerve cell
(transmits)

41. Animal Cell Anatomy

Plasma membrane:
‘outer surface that
‘regulates entrance and

Nucleus: command center of cell

Nuclear envelope: double

Cytoskeleton: maintains membrane with nuclear pores,

cell shape and assists movement that encloses nucleus

of cell parts: - ch diffuse threads
‘containing DNA and protein

‘Nucleolus: region that produces

cylinders that move
organelles

intermediate mente
protestors the provi N y Fe aan
Col of shape J Fibosomes cha synthesize
Actin filaments: protein pees
e ren Smooth ER ct
hinge ot Ene ; ZA We

> iid moles

oles: short > . Peroxisome: vesicle
‘of microtubules A

Centrosome: microrubule
organizing center that arcs that ca
ontains à pal of centrioles ( but protein synthesis

lysosome’: vesicle that > Irtosomecst
digest macromolecles . Heron simuhanssushy
and even cal pars symhertsng ame poten

Vesicle small membrane:

Sounded ase tot sores

and wanepors substances

cytoplasm: semifuid that carries out cellular respiration,

producing ATP molecules

4

Golgi apparatus: processes, package

and secretes modified proteins

“notin plant cells

42. Eukaryotic Cells: Organelles

e Eukaryotic cells are compartmentalized
— They contain small structures called organelles

+ Perform specific functions
+ Isolates reactions from others

e Two classes of organelles:

— Endomembrane system:
+ Organelles that communicate with one another
— Via membrane channels
— Via small vesicles
— Energy related organelles
+ Mitochondria & chloroplasts
+ Basically independent & self-sufficient

43. Every Eukaryotic cell has three main
_ parts-

Plasma (cell) membrane - separates inside of cell
from external environment.

Nucleus - organelle that contains the cell’ s DNA and
is Surrounded by a double membrane.

Cytoplasm - everything from the nuclear membrane
to the plasma membrane

44. o. Cytoplasm refers to cytosol plus organelles and

inclusions.

+ Cytosol - contains proteins, enzymes, nutrients,
ions, and other small molecules

+ Organelles - highly organized structures with
characteristic shapes that are specialized for
specific cellular activities.

« Inclusions - are temporary structures in the
cytoplasm that contain secretions and storage
products of the cell.

45. Plasma membrane

e Physical isolation

e Regulation of exchange with the
environment

e Sensitivity to the environment
— Signal transduction

e Structural support

46. Plasma membrane

made of phospholipid, but accounts for only
42% of the weight of the membrane.

» Phosphoslipid is an amphipathic molecule —
phosphate heads on the outside and inside, and
fatty acid tails in the middle.

+ Proteins — important in many functions

+ Also find glycolipids and cholesterol.

- Most of the surface area of the cell membrane is

47. Cell Membrane

"Heads of Maret

phospholipid 1900000000 — Polar head
$ (hydrophilic)

a (hydrophilic)
"Tails" of
phospholipid

48. Cell Membrane

Membrane is fluid
- fatty acid tails are unsaturated

The membrane is selectively
permeable - it allows fat soluble
substances to pass through (such as
steroid hormones) and some other
small, uncharged molecules.

Cholesterol is a large molecule, and
helps to stabilize the membrane.

49. Membrane carbohydrates
e 3-5 % of membrane
e Proteoglycans, glycoproteins and
glycolipids
e Gylcocalyx
— Lubrication and protection
— Anchoring and locomotion
— Specificity in binding
— Recognition

50. Structure of Proteoglycans & Glycocalyx

Core prot
Glycosaminoglycan Es

Hyaluronan
molecule

51. Cell Membrane

Fluid mosaic model - proteins float like icebergs
in a sea of phospholipids.

Proteins can be integral proteins — go all the
way through the membrane, or may be
peripheral proteins -bound to the inside or
outside membrane.

52. Extracellular side Cell Membrane Double
of membrane layer of
Fibrous proteins phospholipid
molecules
Carbohydrate

Globular Lg molecules
protein ;

Hydrophilic
C o ph Did += pho: pre

53. Membrane proteins

Integral Proteins can be channels or
transporters.

Peripheral proteins can be receptors,
enzymes or can be cell identity markers

54. Membrane proteins

e Anchoring proteins
e Recognition proteins
e Enzymes

e Receptor proteins

e Carrier proteins

e Channels

55. Intercelluar junctions

Tight junctions — membranes of adjacent cells
bound together by occludins and claudins
forming an impermeable junction.

Desmosomes are protein “spot welds” in skin
and cardiac muscle:

— plaques, linker protein filaments, and thicker
filaments across inside of cell

56. Intercellular junctions

e Gap junctions are tubular channels
(connexons) that connect the cytoplasm
of one cell with that of another.

— lons, simple sugars and other small molecules

e Cellular Adhesion Molecules help cells
form temporary attachments to other cells.
CAMs

57. Intercellular Junctions

Nucleus

Nucleolus

Gap junction Tight juntion Cell membrane

58. CAMs

Cell Adhesion actes
CAM) il

White blood cell

Adhesion

Adhesion
receptor
proteins

59. Membrane proteins

Anchoring proteins

Recognition proteins

Enzymes

Receptor proteins

— Ligands bind

Carrier proteins

— allows establishment of electrochemical gradient
Channels

Rafts -lipid rafts — tails saturated; more
cholesterol

60. Membrane Physiology

e Cell membrane function:
— Cellular communication
— Establish an electrochemical gradient
— Are selectively permeable
+ Lipids
» Size
» Electrical charge
» Presence of channels and transporters

61. Movement of materials

e Passive processes:
— Depend on concentration and kinetic
energy
— Do not require energy

— Move substances from an area of high
concentration to an area of low
concentration

+ Down a concentration gradient

62. e Rate depends on:

Diffusion

— Temperature

— Gradient size

— Distance

— Molecule size

- Electrical forces
e Reaches equilibrium or
e Physiological steady state

63. Diffusion

64. lon

2
>
©

2
©
E
3
E
=
o

©
£
E

iffus

9 Sugar molecule

Permeable
membrane

65. Fick’ s Law of Diffusion

nn DA Ap
Rate of diffusion = —

D = diffusion constant (molecule specific)

A = area over which diffusion occurs

Ap = pressure difference between two sides

d = distance over which diffusion occurs
Maximized by increasing surface area, increasing the

concentration difference, and decreasing the distance over
which diffusion occurs

66. e Simple diffusion
e Channel mediated diffusion
0.8 nm
Size and charge
Interaction between ion and channel walls
Rate limited by number of suitable channels
- Na, K, Cl pass through membranes at a rate
comparable to simple diffusion

67. Osmosis

e Movement of WATER through a selectively
permeable membrane

e Moves according to the conc. of water
e Osmotic pressure

68. Osmosis

selectvey OSMOSIS Osmosis
© Sugar molecul: Water .
Membrane o Water molecule Ossugar Selectively Permeable Membrane

Low Sugar Concentration High Sugar Concentration
High Water Concentration Low Water Concentration

69. Concentration of one solution relative to another
(conc. in cytoplasm)

e Isotonic — equal concentrations
0.9 % NaCl or 5% glucose soln.

e Hypertonic — more concentrated
e Hypotonic - less concentrated

70. Human Red Blood Cells

70

71. =
4

Cell in
Isotonic
Solution

71

72. Cellina
=

hypertonic
solution

crenation

73. Cellina
hypotonic
solution

74. osmosis

e Eliminates conc. differences faster than
solute diffusion

e Aquaporins - water channels

75. Facilitated diffusion

e Uses carrier molecules
e Down a conc. gradient
e Specificity

e Saturation limits

e Regulation

76. Facilitated diffusion

Facilitated
Diffusion

Protein
carrier
molecule

Transported
substance o
Region of lower
concentration
o o

o
Cell ö o ==" o
membrane a 0

77. Filtration

-a type of bulk flow where the
movement of water and dissolved
substances across a membrane
is due to gravity or hydrostatic
pressure (water pressure).

78. Filter paper
Pape ¿= Water and
solids

Filtration

+ Gravitational force —

79. Afferent Glomerular Capillary
arteriole filtrate endothelium

Proximal
convoluted
tubule

Glomerulus

Glomerular
capsule

Blood Fenestrae Podocyte
Efferent flow
arteriole

(a) (b)

80. Active Transport

Active Transport

e Depends on the use of Exteel E
energy (ATP) ® +:
e Moves substances up a
concentration gradient (up
hill)
e These systems are often called
“pumps”
Na+ / K+ pump - Na/K ATPase
Others carry Ca**, Mg**, I", Cl and Fe**

81. Active transport

e Counter transport
Exchange pump
e Cotransport or symport

Move two different substances in same
direction

One down a conc. Gradient
Use of energy to pump one substance back out

81

82. Active transport

Carrier Region with altered
of higher shape
concentration

Binding site Carrier protein Alan epored
aA particle

Cell membrane

Kr of lower
Phospholipid concentration
molecules

82

83. Vesicular Transport

Exocytosis — moving substances outside the cell

Endocytosis - taking substances into the cell
clathrin proteins

Pinocytosis — “cell drinking”
Phagocytosis — “cell eating”

Receptor mediated endocytosis

83

84. Pinocytosis
Cell Fluid
membrane Fluid-filled
. ucleolus | ¢
Nucleus

Cytoplasm

84

85. Phagocytosis
Cell Vesicle
membrane "Partie rn
-Q SER >
Nucleus

Nucleolus

85

86. Receptor mediated endocytosis

er DEEE Receptor-Mediated Endocytosis
EXTRACELLULAR FLUID jo js . > 5

5 © e Ligands bi 2 . > Oo
7

to rec
fey Target molecules (ligands) bind to
receptors in plasma membrane.

e

‘Areas coated with ligands form
deep pockets in plasma membrane
surface.

©

Pockets pinch off, forming
‘endosomes known as coated
vesicles.

Coated vesicles fuse with primary

Oo lysosomes to form secondary
Fusion lysosomes.
Primary Ligands are removed and
lysosome absorbed into the cytoplasm.
© VEN
Secondary ©
lysosome The lysosomal and endosomal

membranes separate.

The endosome fuses with the
plasma membrane, and the
receptors are again available for

87. Endoplasmic
reticulum

Golgi
apparatus

Nucleus

87

88. Extracellular
fluid

. eS
Plasma membrane sa a
SNARE : x
QUEUE
SU

‘Vesicle

‘Molecules to
be secreted

Secretory vesicle
Cytoplasm

89. Transcytosis
HIV - infected Anal or
white blood cells vaginal canal
DD Pr bud
HIV ~Receptor-mediated

Lining of ra endocytosis
anus or
vagina
(epithelial
cells)

Receptor-mediated

De
GO) (5 D

Virus infects
white blood cells on
other side of lining

89

90. Nucleus

Nuclear

e Structure: the nucleus is a
sphere that contains another
sphere called a nucleolus

e Function: -storage center of
cell’s DNA
-manages cell functions

Anatomy
of the
Nucleus

91. Cytoplasm

e Structure: gelatin-like fluid that lies inside
the cell membrane

e Function: -contains salts, minerals and
organic molecules

-surrounds the organelles

92. e Structure: a network of
thin, fibrous elements
made up of microtubules SE

(hollow tubes) and

microfilaments (threads \

made out of actin)

e Function: -acts as a
support system for
organelles
-maintains cell shape

y

N
Li
N LA

DEN NEN
SAN NE

0.25 um
Plasma
Membrane
Endoplasmic Microtubule

Reticulum 4 À
Mitochondrion

Microfilamonts

and Intermediate
Filaments

93. bound to GTP 8

Tubulin dimer
bound to GDP

y Tubulin Shrinking microtubule

‘Capping

proteins

Growing microtubule
Paused microtubule (neither polymerizing
nor depolymerizing)

Nature Reviews | Neuroscience

93

94. e Structure: consist of two
subunits made of protein
and RNA

e Function: location of protein
synthesis

Large subunit

/

95. Endoplasmic Reticulum

e Structure: a system of membranous tubules and sacs

e Function: intercellular highway (a path along which
molecules move from one part of the cell to another)

e Two types:
Rough Endoplasmic Reticulum
Smooth Endoplasmic Reticulum

96. e Rough Endoplasmic
Reticulum (RER):
prominent in cells that
make large amounts of
proteins to be exported
from the cell or inserted
into the cell membrane

Covered with ribosomes

97. This is an electron microscope image showing part of the rough endoplasmic
reticulum in a plant root cell from maize. The dark spots are ribosomes.

98. Smooth Endoplasmic Reticulum

e Smooth Endoplasmic
Reticulum (SER): involved in
the synthesis of lipids and
breakdown of toxic substances

Not covered with ribosomes

99. e Structure: stacked flat sacs

e Function: receives proteins from
the RER and distributes them to
other organelles or out of the
cell (receiving, processing,
packaging, and shipping)

100. Mitochondria Structural Features

e Structure: folded
membrane within an outer
membrane

The folds of the inner
membrane are called
cristae

Figure 1

e Function: -converts energy
stored in food into usable maiz cristae a
energy for work

cellular respiration

101. Electron Transport Chain

cn

ATP
Synthase

AUR Citric

. acid
Matrix Ney

Succinate
Fumarate

cing
H Intermembrane space

REED EEK EKEKEEE EEK EEE EEE EEE

Inner membrane

102. ETC

Building proton gradient!

membrane

NADH > NAD* +(H)

103. Inner.
mitochondrial

Intermembrane.
space

Inner
mitochondrial
membrane
(carrying electrons
from food)
Mitochondrial
matrix

Electron transport chain Oxidative phosphorylation

electrons
flow downhill
to O,

104. e Structure: spherical organelles
that contain hydrolytic
enzymes within single
membranes

e Function: breaks down food
particles, invading objects, or
worn out cell parts

105. Peroxisomes

e Structure: spherical
organelles that contain
enzymes within single
membranes

e Function: Degrade
hydrogen peroxide, a toxic
compound that can be
produced during
metabolism.

106. Cilia and Flagella

e Structure: hair-like organelles that extend from the
surface of cells

When they are present in large numbers on a cell
they are called cilia

When they are less numerous and longer they are
called flagella

Both organelles are composed of nine pairs of
microtubules arranged around a central pair.

e Function: cell motility

107. fused pair of
microtubules —=

Power stroke Recovery stroke 4
protein "arms" EE 4 Y

Movement of flagellum

@
O central unfused
Bs pair of = >
o microtubules :
>

0.1 micrometer

108. Basal Bodies

e The microtubule assembly of a cilium or
flagellum is anchored in the cell by a basal body.

e Structurally identical to a centriole

109. e Structure: composed
of nine sets of triplet
microtubules arranged
in a ring

Exist in pairs

e Function: centrioles
play a major role in cell
division (mitosis)

Microtubule

Centrioles

110. e Structure: a sac of fluid
surrounded by a membrane
Very large in plants
e Function: used for
temporary storage of
wastes, nutrients, and water

111. Golgi complex

Vesicles arriving Rough endoplasmic
from RER to cis reticulum (RER)
face of Golgi

Cell

membrane

112. Secretory Pathway

Golgi complex

Vesicles arriving
from RER to cis
face of Golgi

Rough endoplasmic
reticulum (RER)

membrane

113. (b) THE SECRETORY PATHWAY: A MODEL

Rough ERE

Golgi apparatus

Rough endoplasmic

reticulum

Flow of
material

Proteins for use“

within the cell

—

Inside of cell

Golgi
apparatus

114. Animal Cell

Mitochondrion

Flagellum

Peroxisome

Centrioles

NUCLEUS
Microfilaments ——= Nucleolus
Rough
Microtubules endoplasmic

reticulum
Ribosomes

Lysosome

Plasma
membrane

: Smooth endoplasmic
Golgi apparatus reticulum

115. The Structures of a Heart (Animal Organ)

VENTRICLE

116. e Several organs and tissues work together
to carry out a particular set of functions ina
co-ordinated way

— Human : digestive, respiratory, excretory,
circulatory and reproductive systems
— Plant : root and shoot systems

117. Human Body Systems

Examplessofsystemss
& Digestive System

& Respiratory System
© Circulatory System

& Nervous System

® Reproductive System

118. Levels of Organization

x CELLS (muscle cells,nerve cells)
x | (muscle, epithelium)

x ORGANS (heart, lungs, stomach)
x (circulatory system)

x ORGANISM (human)

119. It’s You!