1. Module 1
Introduction to the study of Cell and
Molecular Biology
https://poweredtemplate.com/01247/0/index.html
2. At the end of this module, the students should
be able to:
1. Understand how cell was discovered
2. Identify the basic properties of cell
3. Differentiate the two fundamental classes of cell
Learning Objectives
3. Cell Discovery
• 13th Century
- spectacles were first made
• End of 16th Century
- first compound microscope were
constructed
• 1665 Robert Hooke
- first discovered cells
- piece of cork
• 1676 Anton von Leeuwenhoek
- first to examine animacules
- drop of pond water
4. Cell Discovery
• 1830 Matthias Schleiden
- German botanist
- plants were made up of cells
• 1839 Theodor Schwann
- German zoologist
- animals are made up of cells
• 1855 Rudolf Virchow
- German pathologist
- cells arise from pre existing cells
5. Cell Theory
1. Cell is the basic unit of life
2. All living things are composed of one
or more cells
3. Cells came from pre-existing cells
6. Basic Properties of Cells
• Cells Are Highly Complex and Organized
- parts are in their proper places
- less tolerance of errors
- more regulation and control
- cellular activities are precise
7. Basic Properties of Cells
• Cells Possess a Genetic Program and the
Means to Use it
- DNA contained information (genes)
- genes constitute the blueprints for
constructing cellular structures, directions
for running cellular activities
8. Basic Properties of Cells
• Cell Are Capable of Producing More of
Themselves
- cells division
- genetic material faithfully duplicated
9. Basic Properties of Cells
• Cells Acquire and Utilize Energy
- energy from the sun
- photosynthesis convert light energy to
chemical energy
- plants: sucrose or starch
- animals: glucose (glycogen)
- spends large amount of energy in
breaking and rebuilding macromolecules
10. Basic Properties of Cells
• Cells Carry out a Variety of Chemical
Reactions
- undergo different chemical reactions
- uses enzymes
- Metabolism: sum total of chemical
reactions
11. Basic Properties of Cells
• Cells Engage in Mechanical Activities
- material transport
- assembly and disassembly of structures
- move from one place to another
- due to changes in the shape of “motor
proteins”
12. Basic Properties of Cells
• Cells are Able to Respond to Stimuli
- adapts to the environment
- covered with receptors that interact with
substances in the environment
- receptors provide pathways that can
evoke responses
- alter metabolic activities, moving from
one place to another, committing suicide
13. Basic Properties of Cells
• Cells are Capable of Self-Regulation
- cells are robust (durable)
- can return to its appropriate state
14. Basic Properties of Cells
• Cells Evolve
- modify properties that will be beneficial
15. Two Fundamentally Different
Classes of Cells
• Features common to Eukaryotes and
Prokaryotes
- similar composition of plasma
membrane
- genetic material in DNA
- similar mechanism for transcription and
translation
-same metabolic pathways
16. Features common to
Eukaryotes and Prokaryotes
- similar apparatus for conservation of
chemical energy
- similar mechanism of photosynthesis
- similar mechanism for synthesizing and
inserting membrane proteins
-similar construction of protein digesting
structure
17. Difference between
Prokaryotes and Eukaryotes
Attributes Prokaryotes Eukaryotes
Cell Size Smaller Larger
Presence of Nucleus Absent Present
How genetic material
is stored in the cell
Located in an area in
cytoplasm (nucleoid)
Located in the
Nucleus
Reproduction Binary fission Mitosis
Presence of
membrane bound
organelles
Absent Present
18. Eukaryotic Cell organelles
Golgi complex Materials are sorted, modified and
transported
Cell wall Addition structure in plant cell
Chloroplast site of photosynthesis
Golgi complex Materials are sorted, modified and
transported
Cell wall Addition structure in plant cell
Chloroplast site of photosynthesis
Golgi complex Materials are sorted, modified and
transported
Cell wall Addition structure in plant cell
Chloroplast site of photosynthesis
19. Eukaryotic Cell organelles
Vacuoles Storage
Lysosome Contains enzymes for cellular
processes
Plasma Membrane Protection of the cell
Cilia/Flagella For locomotion/movement
20. Model Animal Cell
Organelles = membrane bound
structures inside a cell that perform
specific functions required by the
cell.
22. Cell MEMBRANE (cont.)
FUNCTIONS of the Cell Membrane:
1. Separates the inside of the cell from the outside environment.
2. Transport proteins control what enters and leaves the cell.
3. Receptor proteins communicate between cells and with anything in the
environment.
23. Cell Communication
Some cells can send signals to other cells.
Ex. Nerve cells sending chemical signals, called
impulses to other nerve cells. This is how your brain tells
your finger that it has touched a hot stove!
24. Ex. Plant hormones stimulate the growth and death of
plant cells.
Auxin: responsible for the growth
pattern of plants toward sunlight
Gibberellins tell the plant embryo to
cease being dormant and germinate.
Cytokinins promote cell division and
differentiation.
25. Cytoplasm = jelly-like filling that holds organelles
Centrioles = used in cell division and replication
Surface Area: Volume Lab
http://www.biologyjunction.com/cell_size.htm
28. • Structure
– double membrane
• Function
– make ATP energy
– cellular respiration
• sugar + O2 ATP
• fuels the work of life
Mitochondria
ATP
29. • 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
Plants make energy two
ways!
ATP
ATP
sugar
30. Mitochondria are in both cells!
animal cells plant cells
mitochondria
Chloroplast/plastid
Chloroplasts are only in plant cells.
31. When things go bad…
• Diseases of lysosomes are fatal
– digestive enzyme not working in lysosome
– picks up food, but can’t digest it
• lysosomes fill up with undigested material
– grow larger & larger until disrupts cell & organ
function
• example:
Tay-Sachs disease
build up undigested fat
in brain cells
Tay Sachs Disease
http://www.teachersdomain.org/resource/tdc02.sci.life.gen.onewrong/
32. But sometimes cells need to die…
• Lysosomes can be used to kill cells when they
are supposed to be destroyed
– some cells need to die as a part of normal
development in an organism
– “auto-destruct” process
• lysosomes break open and kill cell
• cell “suicide”
33. Example 1 of necessary Lysosome work:
Tadpoles must re-absorb their tails when becoming a frog.
34. 15 weeks
6 weeks
syndactyly
Example 2 of necessary Lysosome work:
During human fetal development cells must be destroyed to
separate fingers and toes.
35. Nucleus
• Function
– control center of cell
– protects DNA
• instructions for building proteins
• Structure
– nuclear membrane
– nucleolus
• ribosome factory
– chromosomes
• DNA
Where is the nucleus in a bacterial cell?
36. Ribosomes on ER
Ribosomes
• Function
– protein factories
– read instructions to build proteins from DNA
• Structure
– 2 subunits
– some free in cytoplasm
– some attached to ER large
subunit
small
subunit
37. Endoplasmic Reticulum
• Function
– part of protein factory
• helps complete the
proteins
– makes membranes
• Structure
– rough ER
• ribosomes attached
• works on proteins
– smooth ER
• makes membranes
38. 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
helps finish proteins
makes membranes
39. transport vesicles
vesicles
carrying proteins
• Function
– finishes, sorts, labels & ships proteins
• like UPS headquarters
– shipping & receiving department
– ships proteins in vesicles
• “UPS trucks”
• Structure
– membrane sacs
Golgi Apparatus
