The first few topics on general biology as aid to LET review. My humble contribution

1. What is Biology?
Prepared by Ana Carla T. Villarmente

2. Biology
• “bios” = life
• “logus” = study
• BIOLOGY = study of life
• The study of life
extends from the
microscopic scale of the
molecules and cells that
make up organisms to
the global scale of the
entire living planet.

3. Branches of Biology
• Anatomy • Histology- cells and
• Biochemistry tissue
• Biotechnology • Ichthyology- fish
• Botany • Microbiology-
• microorganisms
Cell Biology/ cytology
• Ornithology-birds
• Ecology
• • Pathology- diseases
Entomology
• Taxonomy- naming and
• Genetics
classification, etc. etc

4. Characteristics of Living Things
• Order
• Evolutionary adaptation
• Response to the
environment
• Regulation
• Energy processing
• Growth and
development
• Reproduction

5. Levels of Biological Organization
Biosphere= all ecosystems
Ecosystem= consists of all organisms living
in a particular area, as well as the
nonliving, physical components of the
environment
Community= consists of various
populations of organisms living together
in a given area
Population= a group of organisms of the
same species in any given area.
Organism= within a population there are
organisms, just one of those organisms is
called an organism. For example, within a
population of lions, there is a lion.

6. Levels of Biological
Organization.p2
Organ system= consists of different organs
that work together for a specific function.
Organ= consists of different tissues that
function together to do a certain job
Tissue= consists of similar cells that work
together
Cell= the smallest unit of life that is able to
carry out all the functions of living things
Molecule= consists of different atoms. For
example, DNA, within DNA there are
oxygen atoms and different proteins.
Atom= the smallest unit of matter that has
the chemical properties of a particular
element.

7. Chemical Foundations of Biology
• Organic molecules
a. Carbohydrates
b. Protein
c. Nucleic acid
d. Fats and lipids
• Inorganic molecules
• Vitamins
• Elements
• Water

8. Organic molecules

9. Inorganic molecules

10. Parts of the cell
• 3 main parts:
1. Plasma membrane
2. Cytoplasm and
organelles
3. nucleus

11. Parts of the cell
1.Plasma membrane or
cell membrane • All cells are protected by a
membrane called the cell
membrane. Plant cells
however also have a cell
wall in addition...
• It is the outermost cell
surface which separates the
cell from the external
environment

12. 2. Cytoplasm and organelles
• a. Endoplasmic Reticulum - The
• The functions of animal endoplasmic reticulum is a
cell are all carried out by network for transportation of
certain critical substances in and
the different cell out of the nucleus. The
organelles. These cell endoplasmic reticulum is seen
organelles function as a like a network of interconnecting
pathways to enable the transport
unit and regulate the of molecules. There are two kinds
activities of the cell on of ER, namely Rough ER and
Smooth ER. Rough ER has
the whole. The different ribosome molecules attached to
cell organelles present in its surface while the smooth ER
an animal cell are does not have ribosome
molecules attached to its surface.

13. • b. Golgi Apparatus - The Golgi
• c. Lysosomes - Lysosomes are
apparatus is involved with
processing and packaging of referred to as suicide bags of
the molecules synthesized by the cell. They are involved in
the cell mainly the proteins clearing the unwanted and
ready for secretion. The ER
transports the proteins in their waste materials from the cell.
crude form to the golgi The lysosomes contain
apparatus. The golgi apparatus hydrolytic enzymes that are
packages the proteins destructive. they kill the toxic
developing them into primary,
secondary and tertiary materials of the cell time to
proteins respectively. time. They engulf materials
like damaged organelles, virus,
bacteria and food particles.

14. • d. Mitochondria/
mitochondrion - The
mitochondria is also referred
to as the power house of the e. Ribosomes - The Ribosome
cell. It is a double membrane is involved in protein
organelle that helps in
energy production for the synthesis. It consists of two
cell. The energy is generated sub units. Protein synthesis
in the form of ATP. primarily occurs in the
Mitochondria also has its
own genetic material called ribosomes. The ribosomes
the mitochondrial DNA may be found freely floating
which is circular. The energy in the cytoplasm or may be
is generated from the
glucose we take in by a found attached to the ER.
process called the cellular
respiration.

15. Functions of the Cell
• g. Vacuole - The vacuole is a h. Cytoskeleton
large empty storage • An interconnected system
organelle. They store excess of fibers, threads and
water or food. It is present interwoven molecules that
in many numbers within the give structure to the cell
cell floating in the • Main components:
cytoplasm. (More microtubules,
discussion in plant cells) microfilaments, and
intermediate filaments. All
are assembled from
subunits of protein.

16. h. Cytoskeleton • i. Centriole
• An interconnected system • It is a cylinder-like structure
of fibers, threads and that occurs in pairs
interwoven molecules that • Centrioles function in cell
give stucture to the cell division

17. • The cells perform various activities with the aid of the many
cell organelles. These cells function together as a unit and
form tissue, for example Muscle tissue ( cluster of muscle
cells ), A group of similar tissues join together to form an
Organ for example stomach, Liver etc. A group of similarly
functioning organs group together to form an organ system
for example Digestive system, Respiratory system.
• Thus, these cells very tiny and invisible to the naked eye
perform all the activities in coordination with the other body
cells and help the organism survive.

18. 3. Cell Nucleus
• 1. Cell Nucleus - The nucleus is
referred to as the heart of the
cell. The nucleus houses the
genetic material of the organism
which is the DNA. DNA
replication and RNA synthesis
occurs in the nucleus. It regulates
the activities of the other cell
organelles thus a very important The double helix: DNA or
cell organelle. The cell nucleus is
bound by a definite membrane deoxyribonucleic acid make up
called the nuclear membrane the chromosomes and are the
that separates the nucleus from base of the genetic code.
the cytoplasm.

19. The discovery of the double elix
• The realization that the
structure of DNA is that of a
double-helix by which
genetic information is
James D. Watson,
stored and copied in living
Francis Crick, and
organisms is widely
Maurice Wilkins each
considered one of the most
received one third of
important scientific
the 1962
discoveries of the 20th
Nobel Prize in Physiology or M
century..
for their contributions
to the discovery

21. Plant cells are larger than animal cells
• Plant cells can be larger than animal cells
• Normal range for an animal cell: from 10 to
30 micrometers
• Plant cell: from 10 to 100 micrometers.
• Main structural differences between plant and
animal cells: additional structures found in
plant cells. These structures include:
chloroplasts, the cell wall, and vacuoles.

22. Chloroplasts
• Plant cells use sunlight as their
energy source; the sunlight must be
converted into energy inside the
cell in a process called
photosynthesis. Chloroplasts are
the structures that perform this
function. They are rather large,
double membrane-bound
structures (about 5 micrometers
across) that contain the substance
chlorophyll, which absorbs sunlight.
Additional membranes within the (In animal cells, the mitochondria
chloroplast contain the structures produces the majority of the cells
that actually carry out energy from food. It does not have
photosynthesis. the same function in plant cells).

23. Vacuoles
• Vacuoles are large, liquid-filled
organelles found only in plant cells.
Vacuoles can occupy up to 90% of a
cell's volume and have a single
membrane. Their main function is
as a space-filler in the cell, but they
can also fill digestive functions
similar to lysosomes (which are also
present in plant cells). Vacuoles
contain a number of enzymes that
perform diverse functions, and
their interiors can be used as
storage for nutrients or, as
mentioned, provide a place to
degrade unwanted substances.

24. The Cell Wall
• Another structural
difference between in plant
cells is the presence of a
rigid cell wall surrounding
the cell membrane. This
wall can range from 0.1 to
10 micrometers thick and is
composed of fats and
sugars. The tough wall gives
added stability and
protection to the plant cell.

25. The Microscope and Microscopy

26. • Microscope – a tool in
Biology
• Microscopy – is a
technique in used to
examine biological
structure, function, and
procceses. Uses different
types of microscopes,
specimen and stains.
• « Discovery in Science is
parallel to the invention
of tools. »

28. – Phase and Contrast
microscope – is an optical
microscopy illumination
technique in which small
phase shifts in the light
passing through a
transparent specimen are
converted into contrast
changes in the image.
• Electron microscope - is a
type of microscope that
uses a particle beam of
electrons to illuminate the
specimen and produce a
magnified image. There are
two types: Scanning
Electron microscope (SEM)
and Transmission Electron
Scanning electron microscope image of an Microscope (TEM).
ant. Its eye is approximately 300 microns
wide. (Dartmouth Electron Microscope
Facility/Dartmouth College)

29. The Cell – the basic unit of life
Type of Size DNA Complexity Example
Cell
Eukaryotic Large True Complex Human
Eubacteria Small Circular Simple Bacteria
Archaea Small Circular Simple Thermophil
ic bacteria
3 domains of Life (Three types) : Eukaryotic, Eubacteria, Archaea

30. Transport in & out of the cell
•Two kinds : passive and active
Type of transport Passive Active
Driving energy Kinetic ATP
Types Diffusion, Osmosis, Electron pump, Co-
Facilitated diffusion, transport,
exocytosis,
endocytosis,
pinocytosis,