2. Objectives
1. Trace the history of the discovery of the cell.
2. Discuss cells as the fundamental unit of
living organisms (Cell Theory)
3. Identify the organelles found inside a cell.
4. Differentiate plant and animal cells
according to the presence or absence of
certain organelles.
5. Prokaryotes and Eukaryotes
3. Living Organisms
Cell
Classification Functions
energy processing
breakdown and
storage
Prokaryotes
(no cell
membrane-bound
nucleus)
Animal
Cell
Bacterial
Cell
Eukaryotes
(true cells)
Plant
Cell
protection
manufacturing
support and
communication
5. Sihay
BASIC fundamental unit of
ALL living organisms
FOUNDATION of life
to Biology
contains the MACHINERIES
needed to maintain Life
basic physiological (functions) and
morphological (structures) unit of life
Cella
6. Why study cells?
▪Cells → Tissues → Organs →
Bodies
◆ bodies are made up of cells
◆ cells do all the work of life!
7. The Work of Life
What jobs do cells have to do for an organism to live…
• Breathe (gas exchange)
• Eat (take in & digest food)
• Make energy (ATP)
• Build molecules (Macromolecules)
• Remove wastes
• Control internal conditions (homeostasis)
• Respond to external environment
• Build more cells
ATP
8. • Make energy
• need energy for all activities
• need to clean up waste produced
while making energy
• Make proteins
• proteins do all the work in a cell,
so we need lots of them
• Make more cells
• for growth
• to replace damaged or diseased cells
The Jobs of Cells
Our
organelles
do all these
jobs!
ATP
9.
10. Cytologist
•Robert Brown – discovered the presence of nucleus within
the cells.
•Félix Dujardin – discovered the sarcode – a life substance
containing gelatinous fluid.
•Johannes Purkinje - coined the term protoplasm – living
material within the cell (nucleus, cytoplasm, and other
organelles).
•Rudolf Albert von Kölliker – coined the term cytoplasm
(semisolid-semiliquid substance inside the cell) from
protoplasm.
11. Cell Theory
States that:
◦All organisms are made up of one or more cells.
- Matthias Schleiden
- Theodor Schwann
◦The cell is the basic unit of structure and
function of all organisms.
◦All cells come only from preexisting cells.
- Rudolph Virchow
11
12. Key roles and function of cells
1. The energy of organisms is formed in the cell. (ATP)
2. Organism can be made of one or more cells. (Prokaryotic and
Eukaryotic)
3. DNA replication and division. (Cell Division)
4. An organism carrying certain chemical composition of cells
is the same with the species where it belongs. (Exclusivity)
5. The activities in an organism are dependent on the activities
done by the cells. (Function)
13. What is a cell?
A cell is the basic unit of life, from which
larger structures such as tissue and organs
are made.
● Unicellular organisms, such as
bacteria, consist of just a single cell.
● Multicellular organisms consists of
many cells – humans are made from an
estimated 50 trillion cells!
14. How big is a cell?
• Most plant and animal cells are between
0.025 µm and 60 µm in size – around half
the diameter of a human hair – and too
small to see without a microscope.
• The largest cell in the human body is the
female egg cell, (ovum) at around 1,000
µm in diameter.
• The smallest human cell is the sperm
cell – the head is around 5 µm long.
15. Specialized cells
• Most plants and animals are multicellular. The human
body is made up of around 200 different types of cell, all
working together.
• Most cells are specialized, meaning that each type of
cell has a specific structure and function.
• All cells with a nucleus contain the same genes, but
different cells activate different genes so they only
produce the proteins they need.
• However, all cells have certain common features and
structures called organelles.
18. 18
Prokaryotic Cells
Lack a membrane-bound nucleus
Structurally smaller and simpler than eukaryotic cells (which
have a nucleus).
Prokaryotic cells are placed in two taxonomic domains:
◦Bacteria
◦Archaea
◦Live in extreme habitats
◦Domains are structurally similar but biochemically different
19. 19
The Structure of Bacteria
Extremely small - 1–1.5 μm wide and 2–6 μm long
Occur in three basic shapes:
◦ Spherical coccus,
◦ Rod-shaped bacillus,
◦ Spiral spirillum (if rigid) or spirochete (if flexible).
Cell Envelope includes:
◦ Plasma membrane - lipid bilayer with imbedded and peripheral protein
◦ Form internal pouches (mesosomes)
◦ Cell wall - maintains the shape of the cell and is strengthened by peptidoglycan
◦ Glycocalyx - layer of polysaccharides on the outside of the cell wall
◦ Well organized and resistant to removal (capsule)
22. 22
The Structure of Bacteria Cytoplasm &
Appendages
Cytoplasm
◦Semifluid solution
◦ Bounded by plasma membrane
◦ Contains water, inorganic and organic molecules, and enzymes.
◦Nucleoid is a region that contains the single, circular DNA molecule.
◦Plasmids are small accessory (extra chromosomal) rings of DNA
Appendages
◦Flagella – Provide motility
◦Fimbriae – small, bristle-like fibers that sprout from the cell surface
◦Sex pili – rigid tubular structures used to pass DNA from cell to cell
23.
24. Eukaryotic Cells
Domain Eukarya includes:
◦Protists
◦Fungi
◦Plants
◦Animals
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
24
25. 25
Eukaryotic Cells: Organelles
Eukaryotic cells are compartmentalized
◦ They contain small structures called organelles
◦ Perform specific functions
◦ Isolates reactions from others
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
27. Organelles
▪Organelles do the work of cells
◆ each structure has a job to do
▪keeps the cell alive; keeps you alive
Model Animal Cell
They’re like
mini-organs!
29. 1. Cells need power!
▪Making
energy
◆ to fuel daily life & growth, the cell must…
▪take in food & digest it
▪take in oxygen (O2)
▪make ATP
▪remove waste
◆ organelles that do this work…
▪cell membrane
▪lysosomes
▪vacuoles & vesicles
▪mitochondria
ATP
30. ▪Function
◆ separates cell from outside
◆ controls what enters or leaves cell
▪O2, CO2, food, H2O, nutrients, waste
◆ recognizes signals from other cells
▪allows communication between cells
▪Structure
◆ double layer of fat
▪phospholipid bilayer
◆ receptor molecules
▪proteins that
receive signals
Cell membrane
33. Cytoplasm
•jelly-like fluid that fills a cell
•made up of mostly water and salt
•contains molecules such as enzymes
•SITE”, “AREA” or “SPACE” where most of
the METABOLIC REACTIONS takes place
•Cytosol – fluid present in the cell membrane
36. Vacuoles & Vesicles
▪Function
◆ moving material
around cell
◆ storage
small food
particle
vesicle
▪Structure
◆ membrane-bound
sac
vacuole filled w/
digestive enzymes
vesicle filled w/
digested nutrients
37. Food & Water storage
Plant cells
contractile
vacuole
Animal cells
central vacuole food vacuole
Protist
38. cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
42. lysosome
▪food digestion
▪garbage disposal &
recycling
cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
43. ▪Function
◆ make ATP energy from cellular
respiration
▪sugar + O2 → ATP
▪fuels the work of life
▪Structure
◆ double membrane
◆ spherical or sausage-shaped
Mitochondria
44.
45. lysosome
▪food digestion
▪garbage disposal &
recycling
cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
mitochondria
▪make ATP energy
from sugar + O2
46. Plants make energy two ways
Mitochondria
make energy from sugar + O2
▪cellular respiration
▪sugar + O2 → ATP
▪Chloroplasts
◆ make energy + sugar from sunlight
▪photosynthesis
▪sunlight + CO2 → ATP & sugar
◆ATP = active energy
◆sugar = stored energy
■ build leaves & roots & fruit
out of the sugars
48. Mitochondria are in both cells!!
animal cells plant cells
mitochondria
chloroplast
49. central vacuole
▪storage: food,
water or waste
mitochondria
▪make ATP in
cellular respiration
chloroplast
▪make ATP & sugars in
photosynthesis
lysosome
▪digestion & clean up
cell wall
▪support
cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material
around organelles
50. Cell Wall
• provides rigidity, shape, support and
protection
• surrounds the cell membrane acts like a
filter due to its semi-permeability
• found only in plant cell
•Plant Cell walls have 3 LAYERS
middle lamella
-a layer rich in pectins
-outermost layer forms the interface between adjacent
plant cells and glues them together
primary cell wall
-generally a thin, flexible and extensible layer formed
while the cell is growing.
-made up of CELLULOSE
secondary cell wall
-a thick layer formed inside the primary cell wall
-contains LIGNIN, which strengthens and waterproofs
the wall
51. 2. Cells need workers = proteins!
▪Making proteins
◆ to run daily life & growth, the cell must…
▪read genes (DNA)
▪build proteins
◆structural proteins (muscle fibers, hair, skin, claws)
◆enzymes (speed up chemical reactions)
◆signals (hormones) & receptors
◆ organelles that do this work…
▪nucleus
▪ribosomes
▪endoplasmic reticulum (ER)
▪Golgi apparatus
52. Proteins do all the
work!
cells
DNA
proteins
one of the major job of cells is to make proteins,
because…
proteins do all the work!
signals
receptors
structural
enzymes
53. Nucleus
▪Function
◆ control center of cell
◆ protects DNA
▪instructions for building proteins
▪Structure
◆ nuclear membrane
◆ nucleolus
▪ribosome factory
◆ chromosomes
▪DNA
56. cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
mitochondria
▪make ATP energy
from sugar + O2
nucleus
▪protects DNA
▪controls cell
chromosomes
▪DNA
lysosome
▪food digestion
▪garbage disposal &
recycling
nucleolus
▪produces
ribosomes
57. Ribosomes
▪Function
◆ protein factories
◆ read instructions to build
proteins from DNA
▪Structure
◆ small granular structures
made up of RNA and proteins
◆ some free in cytoplasm
◆ some attached to ER
58. cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
mitochondria
▪make ATP energy
from sugar + O2
nucleus
▪protects DNA
▪controls cell
ribosomes
▪build proteins
nucleolus
▪produces
ribosomes
lysosome
▪food digestion
▪garbage disposal &
recycling
59. ▪Function
◆ works on proteins
▪helps complete the
proteins after ribosome builds them
◆ makes membranes
▪Structure
◆ rough ER
▪ribosomes attached
▪works on proteins
◆ smooth ER
▪makes membranes
Endoplasmic Reticulum
60.
61. lysosome
▪food digestion
▪garbage disposal &
recycling
cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
mitochondria
▪make ATP energy
from sugar + O2
nucleus
▪protects DNA
▪controls cell
ribosomes
▪builds proteins
ER
▪works on proteins
▪makes membranes
62. ▪Function
◆ finishes, sorts, labels & ships
proteins
◆shipping & receiving department
◆ ships proteins in vesicles
◆ packed and export hormones
and enzymes
▪Structure
◆ membranous organelle forming
a stack of flattened sac located
very close to ER
Golgi Apparatus
65. cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
cytoplasm
▪jelly-like material holding
organelles in place
vacuole & vesicles
▪transport inside cells
▪storage
mitochondria
▪make ATP energy
from sugar + O2
nucleus
▪protects DNA
▪controls cell
ribosomes
▪builds proteins
ER
▪helps finish proteins
▪makes membranes
Golgi apparatus
▪finishes, packages
& ships proteins
lysosome
▪food digestion
▪garbage disposal &
recycling
66. central vacuole
▪storage: food,
water or waste
mitochondria
▪make ATP in
cellular respiration
chloroplast
▪make ATP & sugars in
photosynthesis
cell wall
▪support
cell membrane
▪cell boundary
▪controls movement
of materials in & out
▪recognizes signals
Golgi apparatus
▪finish & ship
proteins
nucleus
▪control cell
▪protects DNA
endoplasmic reticulum
▪processes proteins
▪makes membranes
lysosome
▪digestion & clean up
ribosomes
▪make proteins
cytoplasm
▪jelly-like material
around organelles
nucleolus
▪make ribosomes
67. 3. Cells need to make more cells!
▪Making more cells
◆ to replace, repair & grow,
the cell must…
▪copy their DNA
▪make extra organelles
▪divide the new DNA & new
organelles between 2 new
“daughter” cells
◆ organelles that do this work…
▪nucleus
▪centrioles
68. Cytoskeleton
•a network of thin and fibrous
filaments that serves as the “bones
and muscles” of cell.
•Microfilaments – attached to the
cell membrane responsible for cell
shape and constriction of cytoplasm
during cell division.
•Microtubules – not connected to
cell membrane, they serve as the
anchorage of organelles in the cell.
77. What is a cell?
Animal and plant cells come in different shapes and sizes,
but they all have three basic features.
cell membrane
cytoplasm
nucleus
animal cell plant cell
Plant cells also have some extra features that make them different to
animal cells.
81. How do animal cells specialize?
red blood cell
In animals, the first type of cells in the developing embryo are stem cells. These are
unspecialized cells that go on to form all the different cell types in the adult.
muscle cell
stem cell sperm cell
nerve cell
90. How do plant cells specialize?
Unlike animals, many plant cells retain the ability to differentiate and specialize
throughout their life. These cells are found in tissues called meristems.
sieve cell
leaf cell
root cell
meristem cell
96. What is a cell wall?
All plant cells have a cell wall –
a rigid layer that surrounds the cell
membrane.
The plant cell wall is made from cellulose, a
carbohydrate polymer.
The purpose of the cell wall is to:
● maintain the shape and structure of the cell
● protect the cell’s contents from pathogens
● prevent damage to the cell caused by excess water intake.
Unlike the cell membrane, the cell wall is freely permeable to water
and other molecules.
97. What is a vacuole?
The vacuole is a fluid–filled sac
found within plant cells and some
bacteria.
The vacuole has a range of functions,
including:
● storing waste products
● maintaining the water and pH balance of the cell
● regulating the turgor pressure of the cell.
The site of vacuoles depend on how much water the plant has absorbed.
98. What are chloroplasts?
thylakoids
Chlorophyll is embedded in disk-like structures called thylakoids,
which are arranged into stacks.
Chloroplasts are the site of photosynthesis in plant
cells.
A green pigment in chloroplasts called
chlorophyll absorbs the energy in
sunlight.
This energy is used to convert
carbon dioxide and water into
glucose and oxygen.
102. PETA: Edible Cell Model
Directions:
1. Make an edible cell model, you can
choose between the plant cell and
animal cell.
2. You’re about to make a video of
yourself while making this task.
3. List/Mention all the materials that you
use on this task.
4. You can use any material as long as it is
edible and represent the shape of the
organelles.
5. Put a tag with description on each
organelles.
6. Make a short explanation about your
model.
